Vitamin C Supplements Review
Find the Best Vitamin C
Supplement. Tests and Reviews of Popular Vitamin C Supplements & CL's Top
Picks.
Medically reviewed and
edited by Tod Cooperman, M.D. 
Last Updated
: 11/22/2021 | Initially Posted:
06/06/2020Latest Update: Vitamin C Serums for Wrinkles?
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Table of Contents
Summary
·
Does vitamin C help? If you get sufficient vitamin C from
your diet (such as from one cup of tomato or orange juice), taking more from a
supplement will generally not help. Nevertheless, taking high-dose vitamin C
daily from a supplement during cold season can slightly reduce the risk of
getting a cold, particularly if you are deficient in vitamin C, but won't help
once you're sick. Vitamin C supplementation may also slightly reduce blood
pressure, although it has not been shown to reduce rates of cardiovascular
disease. Taking vitamin C has also been associated with a reduced risk of gout.
(See What It Does)
·
COVID-19 UPDATE: Due to vitamin C's role in maintaining immune system
health, vitamin C supplements are being promoted by some to help prevent
coronavirus (COVID-19), the infection caused by the SARS-CoV-2 virus. While
getting sufficient vitamin C can help maintain a healthy immune system, there
is no evidence that getting more than the daily requirement of vitamin C can
prevent COVID-19 infection. See the COVID-19 section
for more details regarding vitamin C.
·
How much vitamin C should I take? To be sure you're
getting the daily requirement of vitamin C, a supplement providing roughly 50
mg to 100 mg of vitamin C is sufficient for most adults and is quite safe
(see What to Consider When Using). When higher
doses are taken in hopes of reducing the risk of a cold or gout, or to slightly
reduce blood pressure, a typical dose is 500 mg taken twice daily or up to
2,000 mg per day. Be aware, however, that taking more than 500 mg of vitamin C
per day on a regular basis (which will saturate your blood with vitamin C) may
increase your risk of developing cataracts, and taking more than 1,000 mg per
day may also increase your risk of kidney stones. Diarrhea can result from a
single dose of more than 2,000 mg for an adult and lower amounts for children
(see Concerns and Cautions). In short, there is a
risk/benefit trade-off when taking high-dose vitamin C.
·
Which form of vitamin C is best? There are many
forms of vitamin C available (ascorbic acid, sodium ascorbate, calcium
ascorbate, liposomal vitamin C, etc.) but there is no compelling evidence that
one is much better than another. The ascorbate forms may be easier on your
stomach, but you will still run a risk of developing loose stools at a very
high dose. Whole food ingredients (like lemon peel) will provide additional
bioflavonoid compounds, which may be of some benefit, but are not necessary to
meet your nutritional needs, and natural vitamin C, such as from rose hips, is
the exact, same compound, L-ascorbic acid, found in most synthetic vitamin C
supplements. As vitamin C is an acid, products formulated as capsules or
tablets may be safer for your teeth than high-dose liquids, powders (mixed into
liquids), chewables, or gummies (See Forms of Vitamin C).
·
Which vitamin C product is best? Among the vitamin C
supplements shown to be of high quality and Approved in our tests, four were
chosen as CL's Top Picks for
different uses, including one that provides the daily requirement of vitamin C
for less than a penny.
What It Is:
Vitamin
C (ascorbic acid or dehydroascorbic acid) is an essential water-soluble vitamin
that the human body can't manufacture. It must, therefore, come from foods or
supplements. Good sources of vitamin C include many vegetables, such as
broccoli and Brussels sprouts, as well citrus and other fruits, such as kiwi. A
healthful diet should provide the Recommended Dietary Allowance (RDA) of
vitamin C (see ConsumerTips™ for RDAs by age, gender, and life stage).
Vitamin C supplements are typically sold as ascorbic acid, calcium ascorbate
(Ester-C®), sodium ascorbate, ascorbyl palmitate, or
a combination of these forms. Supplements also commonly contain natural sources
of vitamin C such as rose hips (the pear-shaped fruit of the rose, without the
flower's petals) and/or acerola (a cherry-like fruit). (See ConsumerTips™: What to Consider When Buying for more
information about types of vitamin C).
What It Does:
Vitamin C helps the body produce collagen, a basic
component of connective tissue. Collagen is an important structural element in
blood vessel walls, gums, skin, and bones, making it particularly important to
anyone recovering from wounds or surgery. Vitamin C also enhances iron
absorption from supplements and plant foods.
Vitamin C also acts as
an antioxidant, scavenging potentially harmful molecules called
free radicals. Although not established by clinical trials, this antioxidant
activity is theorized by some to help protect against age-related skin changes,
osteoarthritis, and other chronic diseases.
Vitamin C may help
maintain the effectiveness of nitrate drugs, such as nitroglycerin,
taken for chest pain and coronary artery disease.
Vitamin C intake may be
particularly helpful to smokers, who suffer from oxidative stress
and cell damage, which can deplete the body's store of vitamin C.
Although some experts
recommend taking vitamin C to boost iron absorption, research suggest it is
unlikely to have a significant effect (see the Iron Supplements Review details).
Vitamin C deficiency
Prolonged deficiency
of vitamin C may cause scurvy, symptoms of which include non-healing
wounds, petechial rash (tiny red dots on the skin caused by
"microbleeds"), bleeding gums, loosening of teeth, and bone
deformities.
Be aware that even low
blood levels of vitamin C that do not meet the definition of scurvy (< 11.4 mcmol/L) and low vitamin C intakes (30 mg to 60 mg per day
in adults) have been associated with bleeding gums. A review of 15
clinical trials in the U.S., United Kingdom, India and several other countries
concluded that, in people with a vitamin C blood level of 27 mcmol/L or lower, vitamin C supplementation (average dose
and duration 222 mg of vitamin C for 41 days) reduces gingival bleeding —
although the researchers suggest that about half that dose, or 110 mg daily,
would be sufficient, which is greater than the current RDAs for men and women
(except lactating women, for whom the RDA is 120 mg). In people with blood
levels of vitamin C within normal ranges (48 mmol/L to 70 mcmol/L),
supplementation does not appear to reduce gingival bleeding (Hujoel, Nutr Rev 2021).
Deficiency can also
result in iron deficiency anemia due to increased bleeding and decreased
nonheme iron absorption (NIH, 2016).
Vitamin
C deficiency can cause symptoms similar to those found in inflammatory
conditions, such muscle and joint pain. In fact, it was reported
that 10 patients with restrictive eating habits, ages 3 to 20, who had such
symptoms and were initially believed to have juvenile arthritis or other
rheumatic diseases were ultimately found to have abnormally low blood levels of
vitamin C. Supplementation in amounts ranging from 250 mg to 1,000 mg of
vitamin C per day led to a resolution of symptoms in all 10 patients (Stapleton, J Pedatr
2019).
Deficiency
can also impair proper endothelial function (contraction and relaxation of the
lining of blood vessels) and has been implicated in several cases of pulmonary
arterial hypertension (PAH) (high blood pressure in the lungs),
generally with co-occurring iron deficiency. This was reported, for example, in
a man in his 60's with severe vitamin C deficiency due to a poor diet. He
experienced shortness of breath and swelling of the legs, as well as other
symptoms of vitamin C deficiency noted above. His symptoms resolved after five
months of treatment with 1,000 mg of vitamin C taken twice daily. During
treatment his blood levels of vitamin C increased from almost non-detectable
(0.1 mg/dL) to 1.5 mg/dL, which is within normal range (0.2 - 2 mg/dL) (Shameek, Chest 2020).
Cancer
It was theorized that
vitamin C might prevent cancer, but a study found that vitamin C (500 mg per
day) did not reduce the risk of prostate or total cancer in
healthy men aged 50 and older, nor did vitamin E (400 IU per day) (Gaziano, JAMA 2009). Similarly,
a large study of older men in Canada failed to find any association between
intake of vitamin C (from food and/or supplements) and subsequent diagnosis of
prostate cancer or the severity of the disease at the time of diagnosis (Parent, Front Physiol
2018).
Cataracts and macular
degeneration
The same Canadian study
found that vitamin C (500 mg), vitamin E and the combination of the two failed
to prevent cataracts in healthy men (Christen, Arch Opthalmol 2010). It is clear that some amount of vitamin C is important
to reducing the risk and progression of cataracts. A study in the
UK showed that, in comparison to people with the lowest intakes of vitamin C
from their foods, those with the highest intakes were 19% less likely to have
nuclear cataracts and were 33% less likely to experience progression of the
cataracts over the next 10 years. People who had taken supplements (including
multivitamins) were also less likely to have cataracts, but this did not reduce
the risk of subsequent progression (Yonova-Doing, Ophthalmology 2016). Other
long-term studies (more than 10 years) suggest that vitamin C supplementation,
at modest dosage, may reduce the risk of developing cataracts
and that the daily intake of vitamin C needed to saturate the eye is only about
150 mg to 250 mg per day (Jacques, Am J Clin Nutr 1997). A long-term study of a modest-dose
multivitamin (containing 60 mg of vitamin C) showed that the
multi reduced the risk of developing cataracts except when a separate, daily,
high-dose vitamin C supplement (500 mg -- about 6 times the RDA) was added to
the regimen. In summary, over the long-term (10 years or more), it
seems that low-dose vitamin C (60 mg to 250 mg) may help prevent cataracts,
while high-dose does not and may have a negative effect.
Despite this, high-dose
vitamin C (452 mg daily) is part of the AREDS formula that
has been shown to reduce the progression of age-related macular
degeneration.
Colds and immune system
health
Starting
vitamin C supplements prior to getting a cold may
reduce cold duration and severity: An analysis of 44 studies found that when
people developed a cold while taking vitamin C (usually 1 gram daily) their
cold symptoms were slightly less severe (by 5% in one large
study) compared to those who were taking a placebo. The duration of
symptoms was also reduced by about 8% in adults and 14% in children.
Studies evaluating vitamin C supplementation after cold symptoms
develop have not conclusively shown a benefit (Hemila, Cochrane Database Syst Rev 2013). However, an analysis of nine clinical trials published between
1950 and 2001 concluded that, in people who already regularly
supplemented with vitamin C (1 gram or less daily), taking a higher
dose of vitamin C (3 to 4 grams daily) during a cold may slightly shorten the
duration of the cold (by about half a day) and modestly reduce certain symptoms
(chest pain and chills) but not nasal congestion or sore throat, compared to
placebo. This high-dose vitamin C benefit was not seen in people who weren't
already supplementing regularly with vitamin C — again suggesting that some
vitamin C may need to be onboard prior to developing a cold to get a benefit (Ran, Biomed Res Int 2018).
Although studies have
generally not found that taking vitamin C can prevent a cold, this has been
shown to occur in certain situations: The Cochrane Database analysis noted
above found that people undergoing short-term, severe physical stress,
such as running a marathon, had a 52% lower risk of developing a cold if they
took vitamin C (as opposed placebo) for several days before the event (Hemila, Cochrane Database Syst Rev 2013). A
small study of men ages 18 to 35 with low to adequate levels of
vitamin C found that those taking 1 gram of vitamin C daily (500 mg of
crystalline vitamin C taken as a capsule (TwinLab
C-500 Caps) in the morning and, again, in the evening) for two months in
the winter reported fewer colds compared to those taking a placebo (7 vs. 11) (Johnston, Nutrients 2014).
As vitamin C is important
for immune system health, vitamin C supplements have been promoted by some
websites to help fight viral infections other than colds, such as COVID-19, the infection
caused by the SARS-CoV-2 virus. However, there is no evidence that
getting more than the daily requirement of vitamin C can prevent infection from
coronavirus and clinical studies have not shown a clear benefit from giving
high dose vitamin C to COVID patients.
[Update
(3/6/21): The FDA sent a Warning Letter to
Dr. Joseph Mercola on February 18th warning that his promotion of Dr.
Mercola Liposomal Vitamin C as well as his Liposomal Vitamin
D3 and Quercetin and Pterostilbene Advanced supplements
violated federal laws based on claims that these ingredients could prevent or
treat COVID-19. These claims were found by the FDA on Dr. Mercola's website and
blog on February 4th. These claims do not appear on the Liposomal
Vitamin C product tested by ConsumerLab
tested in this Review.]
A study of 214 adults
diagnosed with COVD-19 in Ohio and Florida found that taking a total of 8,000
mg daily of vitamin C (divided over 2 to 3 times per day with meals) daily
did not significantly decrease the duration of symptoms
compared to standard care without vitamin C supplementation. In fact, those
given vitamin C were more likely to experience nausea, diarrhea, and stomach
cramps — common side effects of high-dose vitamin C. There was also no benefit
from combining the vitamin C with high-dose zinc (50 mg daily) or from the zinc
alone (Thomas, JAMA Network Open 2021).
A review of several
studies performed prior to the emergence of COVID-19 revealed that a daily dose
of 1,000 to 6,000 mg of vitamin C (intravenously or by mouth) shortened
the time on ventilation by about 25% for people who required
ventilation for over 10 hours, but it appeared to be less helpful for those on
ventilators for shorter periods (Hemila J Intens Care 2020).
This has prompted the use of high-dose vitamin C for patients in some
hospitals. However, a trial among 56 men and women in China (average age
66) with severe SARS-CoV-2-related pneumonia found that giving extremely
high-dose vitamin C (24,000 mg per day for seven days) intravenously within
48 hours of arrival to ICU slightly improved blood oxygenation but did not
reduce invasive mechanical ventilation-free days or mortality over the 28 days
after admission compared to placebo (Zhang, Ann Intensive Care 2021). Additionally,
a retrospective study among 15 people (average age 72) who were critically ill
with COVID-19 and also in shock found that the mortality rate was very high
(80%) despite treatment with 3,000 mg of vitamin C given in three divided doses
daily for three to five days (along with standard treatment consisting of
hydroxychloroquine, methylprednisone and tocilizumab
when indicated) (Chaudhary, Acute Crit Care 2020).
Blood pressure and blood
sugar
Blood
pressure appears
to be modestly reduced with vitamin C supplements, at least in short-term
studies. A review of 29 such studies, most of which used a daily dose of 500 mg
or 1,000 mg of vitamin C, found average decreases of 3.84 mm Hg and 1.48 mm Hg,
respectively, in systolic and diastolic blood pressures (Juraschek, Am J Clin Nutr 2012).
Among patients with high blood pressure, the decreases were greater: 4.85 mm Hg
and 1.67 mm Hg. Vitamin C was not found to directly prevent or reduces rates of
cardiovascular disease (CVD), although the trials may have been too short (2
weeks to 6 months) to detect an effect. The blood pressure reduction with
vitamin C supplementation is minor compared to that with ACE inhibitors and
diuretics, which reduce pressures by about 10 mm Hg.
Vitamin
C's modest effect on lowering blood pressure may result from lowering the
activity of the endothelin-1 system, relaxing blood vessels. A small, 3-month
study in the U.S. found that giving 500 mg per day of timed-release vitamin C
each morning to overweight and obese individuals (who tend to have elevated
endothelin-1 activity) reduced endothelin-1 activity as much as an exercise
regime of daily aerobic walking for 45 to 60 minutes. The mean blood level of
vitamin C was 1.2 mg/dL (rising in the supplemented group to 1.5 mg/dL),
suggesting that the group was not vitamin C deficient. The researchers suggest
vitamin C as a strategy for reducing endothelin-1-mediated vasoconstrictor tone
in overweight and obese adults (Dow, Am Phys Soc Conf 2015 — abstract not
available).
Another
study among overweight or obese adults, all 27 of whom had type 2
diabetes, showed that 500 mg of vitamin C taken twice daily for four months
not only lowered blood pressure (by an average 7 mm Hg systolic and 5 mm Hg
diastolic) compared to placebo, but also lowered the amount of glucose
in the blood after eating by 36% and reduced by 2.8 hours the period
during which glucose levels were elevated daily. There was no significant
improvement in HbA1c, although this may have been due to the limited size and
duration of the study, according to the researchers (Mason, Diab Obes Metab 2019).
Nonalcoholic
fatty liver disease (NAFLD)
Higher dietary intake of
vitamin C (>146 mg/day) has been associated with a 29% lower odds of nonalcoholic
fatty liver disease (NAFLD) compared to lower intake (<75 mg/day) (Wei, PLOS One 2016). A
study in China among 84 people with recently diagnosed NAFLD — none of whom
were vitamin C deficient — showed that taking 200, 1,000 or 2,000 mg of vitamin
C daily before meals for 12 weeks improved markers of liver function (AST, ALT,
and/or GGT), with those in the 1,000-mg group consistently showing the greatest
benefit. However, the lack of a placebo control group limits the validity of
these results. None of the three groups showed improvements in total
cholesterol or triglyceride levels, or blood levels of albumin (a protein made
by the liver that tends to be lower in people with advanced NAFLD or fibrosis)
(He, Front Nutr
2021).
Risk of death
A long-term study of Americans found the risk of dying over
the course of the study (about 14 years) was lowest when vitamin C levels in
the blood serum were above the lowest levels (the bottom 20% of the population,
i.e., above 15.33 millimol/liter) and the risk
continued to decrease until vitamin C levels reached 45.99 to 59.62 millimol/liter, with no further decrease at higher levels.
The risk of dying specifically from cardiovascular disease followed a similar
pattern, although the risk of dying from cancer continued to decrease even into
the highest blood levels of vitamin C (at or above 60.19 millimol/liter)
(Goyal, Cancer Epidemiol Biomarkers Prev
2013). However, one study suggests that
getting vitamin C from supplements may increase breast cancer risk in women who
already have a high dietary intake of vitamin C. The ten year observational
study among 57,403 women in France found that while those who reported the
highest intakes of vitamin C from foods (> 177.6 mg/ day) had a reduced risk
of postmenopausal breast cancer compared to women reporting the lowest intake
of vitamin C from foods (<101.9 mg/day), women who reported the highest
intakes of vitamin C from foods and also took vitamin C supplements had
an increased risk of postmenopausal breast cancer (Cadeau, Am J Clin Nutr 2016).
Shingles (Herpes zoster)
Low
blood levels of vitamin C (≤45 µmol/L) have been associated with an
increased risk of developing post-herpetic neuralgia -- nerve pain that persists
after shingles (Herpes zoster) lesions have healed (Chen, Br J Nutr 2011).
Vitamin C given intravenously (2.5 to 15 grams daily or every other day for 3
to 14 days), given along with standard treatment, has been shown to reduce this
delayed pain and its severity but not acute shingles pain (Carr J Transl Med 2017; Kim, Ann Dermatol 2016). However, there do not
appear to be any clinical studies investigating the effects of oral vitamin C
supplementation on treating shingles or reducing acute or post-shingles nerve
pain.
Foot ulcers
A small
clinical trial in Australia found that vitamin C supplementation may improve
healing of foot ulcers in people with diabetes mellitus, vascular
disease, and other conditions conducive to foot ulcers, particularly when
patients have low or deficient levels of vitamin C. In the study, 16 older
adults (average age 60) being treated for foot ulcers who had type I or type II
diabetes, vascular disease, neuropathy, or deformed foot architecture were
given 500 mg of vitamin C (as a slow-release tablet) or placebo (1,000 mg
glucosamine — an unusual choice for a placebo) once daily for two months. Half
of the patients in each group had been vitamin C deficient. Complete healing
occurred in all of those who took vitamin C as opposed to only 56% of those who
took the placebo (Gunton, Brit J Nutr 2020).
In men, intake of vitamin
C from supplements is associated with reduced risk of gout.
Compared to men who did not use supplemental vitamin C, intakes of 1,000 to
1,499 mg and more than 1,500 mg were, respectively, associated with 34% and 45%
reductions in the risk of gout (Choi, Arch Intern Med 2009).
This may be due to lower levels of uric acid in the blood with vitamin C
intakes of up to 400-500 mg per day — although there is no further decrease
with higher vitamin C intake (Gao, J Rhematol
2008).
Nail health
Vitamin
C deficiency has been associated with changes in nails such as
koilonychia (spoon nails) and hapalonychia (top of the nail becomes soft and
thin, causing it to bend or break) (Cashman, Clin Dermatol 2010). As discussed
above, vitamin C can enhance iron absorption, and iron deficiency can result in
brittle nails. However, there do not appear to be any clinical
studies demonstrating that vitamin C improves nail health or strength in people
who are not deficient in vitamin C or iron (Scheinfeld, J Drugs Dermatol 2007).
The
science around vitamin C for skin health:
Vitamin C, which is naturally present in the skin, plays a role in collagen
synthesis and may help protect skin against environmental stress due to its
antioxidant effects (Pullar, Nutrients 2017).
Research has shown lower levels of vitamin C in aged or sun-damaged skin, so
there has been interest in applying vitamin C to the skin to boost vitamin C
levels (Rhie,
J Invest Dermatol 2001). However, as discussed below, there
is no compelling evidence that applying vitamin C to the skin provides
meaningful improvement in skin appearance or that it is even well absorbed into
the skin.
A small
study among women (average age 55) with photo-aged skin found that applying a
5% vitamin C serum (Active C, Laboratories La Roche Posay) once daily
for 6 months improved investigator-rated physical properties of the skin
(including hydration, fine and coarse wrinkles, roughness, suppleness,
and sagging skin) by only 2.3 points based on a 17-point global
score compared to an improvement of 1.4 points with the placebo cream
(excipient without vitamin C). Blood levels of vitamin C before or after
topical treatment were not reported (Humbert, Exp Dermatol 2003).
Several
studies have shown that applying sunscreen containing vitamin C in
combination with vitamin E reduced skin damage caused by UV
exposure compared to sunscreen alone (Darr, Acta Derm Venereol 1996; Murray, J Am Acad Dermatol 2008; Grether-Beck, Photochem Photobiol 2015),
but applying vitamin C alone does not appear to be beneficial: One
study showed that applying a formulation containing 5% vitamin C (as L-ascorbic
acid) alone did not prevent UV-induced skin redness compared to placebo
formulation (Dreher, Br J Dermatol 1998).
What to look for in topical vitamin C
products:
First, be aware that vitamin C cannot easily penetrate the outermost layer of
the skin (stratum corneum). In addition, applying vitamin C to the skin does
not appear to boost skin levels if the blood is already saturated, which occurs
with daily intake of 500 mg — although blood levels of vitamin C increase only
marginally with intakes of 200 mg or more per day, which is more than twice the
recommended daily allowance (Levine, Proc Natl Acad Sci USA 1996; Pinnell, Dermatol Surg 2001; Pullar, Nutrients 2017).
Laboratory
research using animal skin showed that best absorption of vitamin C occurred
when a product had a pH level of less than 3.5 and vitamin C concentrations of
10% to 20% (Pinnell, Dermatol Surg 2001). Many products do
not provide this level of detail about their formulations, but among those that
do, ConsumerLab found the following as examples of
products that appear to meet the formulation criteria for maximizing
absorption: Drunk Elephant's C-Firma Fresh (15%
L-ascorbic acid, pH 2.5), Paula's Choice C15 Super Booster (15% ascorbic acid,
pH 3.0), and bioBare Vitamin C, B E
& Ferulic Serum (20% L-ascorbic acid, pH 3.5).
All of these formulations also include vitamin E and ferulic acid, which appear
to help increase stability of the formulation based on laboratory research (Lin, J Am Acad
Dermatol 2003; Lin, J Invest Dermatol 2005).
Derivatives
of vitamin C have been developed in an effort to improve stability and increase
absorption, but these formulations do not appear to be particularly
effective. Phosphate derivatives (e.g., ascorbyl
phosphate) appear to be more stable, but absorption is decreased. Palmitate (e.g.,
ascorbyl palmitate) may improve absorption, although
evidence is mixed and these formulations do not appear to have
greater stability. Glucoside derivates of vitamin C have shown
greater stability and penetration, but it is unknown whether this form gets
converted to the active form (i.e., ascorbic acid) following skin
penetration. Dehydroascorbic acid, which can be converted to
vitamin C in the body, does not appear to increase skin levels of vitamin C
when applied topically (Pinnell, Dermatol Surg 2001; Pullar, Nutrients 2017).
Vitality and mood
A study
of 128 healthy young adults (average age 22) in New Zealand with adequate but
not high blood levels of vitamin C found that taking a chewable tablet
containing 250 mg of vitamin C once daily for 4 weeks increased vitamin C
levels from an average of 30.90 µmol/L to 80.60 µmol/L and slightly improved
some measures of vitality. Vitamin C supplementation reduced
self-reported fatigue by about 3.8 points on a 120-point scale and improved
mental well-being by about 1.3 points on a 56-point scale. Though very modest,
these improvements were statistically significant compared to the placebo
group, which showed no changes in these measures. Taking vitamin C supplements
did not improve self-reported mood disturbances. Similar or slightly greater
improvements were also observed for people given two kiwifruits to eat daily,
which also provided 250 mg of vitamin C daily. The study was funded by Zespri
International Ltd., a marketer of kiwifruit (Conner, Nutrients 2020).
Quality Concerns and
Tests Performed:
Regulations
from the U.S. Food and Drug Administration (FDA) require that any vitamin C
sold as a dietary supplement in the United States contain at least 100% of its
labeled amount, but neither the FDA nor any other federal or state agency
routinely tests vitamin C supplements for quality prior to sale.
ConsumerLab.com, as part of its mission to independently evaluate products that
affect health, wellness, and nutrition, purchased several popular vitamin C
supplements sold in the U.S. and Canada, and tested them to determine whether
they contained their labeled amounts of vitamin C and whether tablets properly
disintegrated (break apart) to enable their absorption. All products with
botanical ingredients or large amounts of minerals were also tested for heavy
metals (lead, cadmium, and arsenic). See How Products Were Evaluated for more
details about the testing.
What CL Found:
Laboratory tests found that each of the ten products selected
for review contained the amount of vitamin C listed on its label, which is an
improvement from 2017 when ConsumerLab.com's testing
revealed problems with 20% of vitamin C supplements (none of failing products
were included in the current review). This year, an additional 12 vitamin C
supplements passed testing through ConsumerLab.com's
voluntary Quality Certification Program.
All of these products are listed as Approved in the table below.
All regular tablet and caplet products were found to properly break apart to
release their ingredients in solution. Products that could potentially be contaminated
with heavy metals (lead, cadmium, and arsenic) due to inclusion of whole herbs
and/or large amounts of minerals were found to not exceed limits for these
metals.
Vitamin C Per Serving
Although adults need only a total of 75 to 120 mg of vitamin C daily from their
entire diets (the recommended daily intake -- and young
children need significantly less — 15 mg to 45 mg), people buying vitamin C supplements
typically are seeking higher intakes for special purposes. In fact, it's a
little hard to find a vitamin C supplement with just the daily requirement —
although it is easy to get this from a multivitamin.
Among the products in this review suggested daily doses ranged from 60 mg to
5,000 mg, as shown below. With such a large a range, it's clear that you can't
just follow the serving instructions on a label: Choose a product that will
provide the amount of vitamin C you need. Particularly for higher doses (e.g.,
over 2,000 mg for adults or 450 mg for young children), it may be preferable to
use the sodium ascorbate or calcium ascorbate (Ester-C) forms to reduce stomach
upset.
Cost
In the graph below, we looked at the cost to obtain 500 mg of vitamin C from
each product. You can see that you can get this much vitamin C for as little as
3 cents from a powder and 4 cents from some capsules and tablets to as much as
$3 from an organic spray. In general, powders, capsules, and tablets are the
least expensive ways to get vitamin C, while special formulations, like
gummies, chewables, liquids, and sprays can cost 10
times as much or more, particularly if they contain organic or other special
ingredients.
Taste
Although not a basis for Approval, we tasted all gummies and sprays as well as
chewable and drinkable products (i.e., liquids or powders intended to be mixed
with liquid). Our taste impressions are shown in the 2nd column of the Results table along with
calorie information from labels since many of these edible forms include sugars
to improve their flavor. Most gummies and chewables
were pleasant tasting, but liquids and powders often were not. It may be best,
anyhow, to take vitamin C as a capsule or tablet to avoid bathing your teeth in
ascorbic acid with the edible forms, which can affect the tooth enamel. This
will also help you avoid unnecessary calories as well as save a little money.
Top Picks:
The
following products are CL's Top Picks for among the Approved
products considering factors such as proven quality, safety, value, and taste
(for non-pill formulations).
Keep in mind that if you already get adequate vitamin C from food (including fortified foods) or
a multivitamin, you may
not need a vitamin C supplement.
To help meet the recommended daily requirement (75 mg to 120 mg for adults):
·
Pill: None of the pills are designed to provide just the daily
requirement of vitamin C at their suggested daily serving. So we have no Top
Pick if you just want the daily requirement.
·
Gummy: We are not fans of gummies, as they cost more than pills,
stick to teeth (which can promote decay), contain sugar and unnecessary
calories, and can lead to overconsumption. With that said, if you still want to
take a gummy, our Top Pick for adults is actually a children's
product, Solgar U-Cubes Vitamin C
Gummies (125 mg of vitamin C and 7.5 Calories per gummy for 11 cents).
We prefer this over Vitafusion Power
C™ (94 mg of vitamin C and 10 Calories per gummy for 21 cents),
as Solgar is less expensive and has
fewer calories.
·
Powder: Solaray Vitamin
C Powder -- Although the labeled serving size (one heaping teaspoon)
of this vitamin C powder provides five thousand milligrams of
vitamin C, you can scale this way back to just get your daily requirement. This
can be mixed into a drink, adding a little bit of tang. For example, just
1/64th of a teaspoon of Solaray powder will provide
about 80 mg of vitamin C. (Below, we've shown what this would look like in a
1/8 teaspoon measuring spoon, dividing one full 1/8 teaspoon of powder in
half, three times, to get down to just 1/64 teaspoon). The cost for
this 80 mg dose would be just $0.0044, i.e., less than half a cent! Even if you
increased this to 1,000 mg of vitamin C by taking 1/5th of a teaspoon, the cost
would be just 6 cents, far less than the 46 cents for the same amount of
vitamin C from a packet of Emergen-C powder. Emergen-C, which is promoted for "Daily
Immune Support," does provide safe amounts of a variety of other vitamins
and minerals, but, interestingly, it does not include vitamin D which
acts as an immunoregulatory hormone and, if given in moderate doses to those
deficient in it, may reduce the risk of respiratory infections.
Just 1/64th of a teaspoon
of Solaray Vitamin C Powder will
provide 80 mg of vitamin C, for half a cent.
For children:
Kids require a lot less vitamin C than adults (just 15 mg at ages 1-3, 25 mg at
ages 4-8, and 45 mg at ages 9 to 13). Unfortunately, all of the children's
products suggest serving sizes that are way above these amounts. For
example, ChildLife Liquid Vitamin C suggests
a dose of ½ to 1 tsp for kids ages 1-3, providing 125 mg to 250 mg of vitamin
C. The 1 tsp dose, therefore, provides a whopping 16.7 times the daily
requirement and starts to approach the daily upper limit of 400 mg for that age
group. The ChildLife liquid is also
medicinal tasting and sour and a child may not like it. Both Solgar U-Cubes and Nature's Plus
Animal Parade provide 125 mg per gummy or chewable tablet,
respectively, which is still high. Ironically, Vitafusion
Power C Gummies (which are intended for adults) actually have a bit
less vitamin C per gummy (94 mg), although this is still more than kids need
and it has more sugar (2 grams) and calories (10) than the other two (Nature's
Plus has the lowest amount at 1 gram of sugar and 5 calories per
chewable tablet). So there are no great choices here for kids, but
taking one gummy or chewable table of any of these would be safe.
For high dose (500+ mg):
·
Nature's Bounty 500 mg (500 mg from ascorbic acid per tablet
for 4 cents) — ascorbic acid
Or
·
Solaray Vitamin C Powder — As noted above,
you can reduce the labeled serving size to get the dose you want. If you want
500 mg, for example, you only need one-tenth of teaspoon. Just don't let the
drink into which you mix the powder sit in our mouth long, to avoid negatively
affecting tooth enamel.
For extremely high dose
(2,000 +mg) At extremely high doses, ascorbic acid can be hard on the
gastrointestinal tract and cause diarrhea, so calcium ascorbate (Ester-C) or
sodium ascorbate may be preferable. Two products provide exclusively calcium
ascorbate: Ester-C tablets (NatureSmart)
and American Health Ester-C (powder). We found the powder,
which has a light brown color, to have an unpleasant earthy taste when mixed
with water, so our Top Pick when taking an extremely high dose
is Ester-C tablets from NatureSmart (500
mg of vitamin C per tablet for 10 cents). You'll also be getting some calcium
with this — 55 mg per tablet.
In our tests in 2017, we approved a sodium ascorbate powder from Bronson
Laboratories (1,000 mg of vitamin C per ¼ tsp). Sodium
ascorbate has a mildly salty taste and will contribute some sodium to your diet
— about 130 milligrams per 1,000 mg of vitamin C.
Test Results by Product:
Listed
below are the test results for 22 supplements containing vitamin C. Ten were
selected by ConsumerLab.com and twelve others (each indicated with a CL flask)
are included for having passed the same tests through ConsumerLab.com's
voluntary Quality Certification Program.
Products appear alphabetically, with those marketed for children listed
separately at the bottom of the table. Products listed as "Approved"
met their label claim and ConsumerLab.com's standards
for vitamin C supplements. Also shown are the claimed amount and form of
vitamin C and daily serving size recommended on the label.
The fourth column provides cost and price comparisons and the fifth column
identifies additional ingredients and notable product features. The full list
of ingredients appears in the last column.
Results of
ConsumerLab.com Testing of Vitamin C Supplements
(Click arrows or swipe left or right to see all columns)
Approval Status
Product Name
(Suggested Serving on Label)
Claimed Amount of Vitamin Cⓘ
Pill Sizeⓘ
Heavy Metalsⓘ
Disintegration
Suggested Serving on Label
Cost for Suggested Serving
[Cost Per 500 mg Vitamin C]
Priced
Notable Features
Full List of Ingredients Per Serving
Capsules and Tablets:
APPROVED
Dr. Mercola Liposomal Vitamin C
Dist. by NHP
2 capsules
1,000 mg (ascorbic acid)
✔
Large capsule
Heavy Metals: NA
Disintegration: NA
Adults, take two (2) capsules daily with water.
$0.53/2 capsules
[$0.27]
$15.99/60 capsules
Soy Free. GMO Free. Gluten Free.
2 capsules
Vitamin C (as Ascorbic Acid) 1,000 mg.
Other Ingredients: Sunflower Lecithin, Medium Chain Triglycerides, Capsule
(Hydroxypropyl Methylcellulose), Beeswax, Paprika Extract.
APPROVED
Top Pick
for extremely high dose (1,000+ mg)
Ester-C 500 mg
Mfd. by NatureSmart,
LLC
2 vegetarian coated tablets
1,000 mg (Ester-C® calcium ascorbate)
✔
Large vegetarian coated tablet
Heavy Metals: Pass
Disintegration: Pass
For adults, take two (2) tablets once daily, preferably with a meal.
$0.20/2 vegetarian coated tablets
[$0.10]
$8.79/90 vegetarian coated tablets
2 vegetarian coated tablets
Calcium 110 mg, C-Sorb™ citrus bioflavonoid complex 204 mg
Non-GMO. No Gluten, No Wheat, No Milk, No Lactose, No Artificial Color,
Flavor, or Sweetener, No Sugar, No Starch, No Soy, No Yeast, No Fish. Sodium
Free. Suitable for Vegetarians.
2 vegetarian coated tablets
Vitamin C (as Ester-C® Calcium Ascorbate) 1,000 mg, Calcium (as Ester-C®
Calcium Ascorbate) 110 mg, C-Sorb™ Citrus Bioflavonoid Complex [Citrus
Bioflavonoid Complex (Citrus spp.) (peel and fruit), Sweet Orange,
Tangerine, Lime, Lemon, Acerola Extract, Rutin,
Hesperidin Complex (Citrus spp.) (peel, Naturally Occurring Vitamin C
Metabolites] 204 mg.
Other Ingredients: Vegetable Cellulose, more...
APPROVED
Garden of Life® Vitamin Code® RAW Vitamin C™
Dist. by Garden of Life LLC
2 vegan capsules
500 mg (whole food sourced)
✔
Large vegan capsule
Heavy Metals: Pass
Disintegration: NA
Adults take 2 capsules daily.
$0.49/2 vegan capsules
[$0.49]
$14.69/60 vegan capsules
2 vegan capsules
RAW organic fruit & vegetable blend 720 mg, RAW probiotic & enzyme
blend 60 mg
Non GMO Project Verified seal. No high heat, synthetic binders, filler,
artificial flavors, sweeteners, colors or additives commonly used in tablets.
Kosher. Gluten Free. Certified Vegan Vegan.org seal.
2 vegan capsules
Vitamin C 500 mg, RAW Organic Fruit & Vegetable Blend [Organic Apple
(fruit), Organic Beet (root), Organic Broccoli (stalk & flower), Organic
Carrot (root), Organic Spinach (leaf), Organic Tomato (fruit), Organic
Strawberry (fruit), Organic Tart Cherry (fruit), Organic Blackberry (fruit),
Organic Green Bell Pepper (fruit), Organic Brussels Sprout (leaf), Organic
Blueberry (fruit), Organic Ginger (root), Organic Garlic (bulb), more...
APPROVED
Jamieson™ Chewable C 500
Dist. by Jamieson Laboratories
1 chewable tablet
500 mg (ascorbic acid, sodium ascorbate)
✔
Medium/large circular chewable tablet
Taste: Sweet and sour taste, not much fruit flavor
(Includes dextrose; Calories not listed)
Heavy Metals: Pass
Disintegration: NA
Adults: Chew 1 to 4 tablets daily.
$0.08/chewable tablet
[$0.08]
$9.99/120 chewable tablets
1 chewable tablet
Supporting botanical blend 7 mg
Vegetarian. No salt (NaCl), lactose, artificial colours,
flavours or preservatives.
1 chewable tablet
Vitamin C (Ascorbic acid, Sodium ascorbate) 500 mg, Supporting botanical blend
[Derived from rutin (Dimorphandra
mollis, pod), hesperidin (Citrus sinensis,
fruit), citrus bioflavonoids (Citrus limon, rind), acerola cherry (4:1)
extract (Malpighia glabra, fruit) equivalent to 5.76 mg raw herb, rose
hips (Rosa canina, fruit)] 7 mg.
Also contains: Dextrose, cellulose, more...
APPROVED
Life Extension® Vitamin C and Bio-Quercetin Phytosome
Dist. by Quality Supplements and Vitamins, Inc.
1 vegetarian tablet
1,000 mg (ascorbic acid)
✔
Medium/large vegetarian tablet
Heavy Metals: NA
Disintegration: Pass
Take one (1) tablet daily with food, or as recommended by a healthcare
practitioner.
$0.08/vegetarian tablet
[$0.04]
$20.00/250 vegetarian tablets
1 vegetarian tablet
Bio-quercetin phytosome 15 mg
Non GMO.
1 vegetarian tablet
Vitamin C (as ascorbic acid) 1,000 mg, Bio-Quercetin phytosome
(providing 5 mg quercetin [from Japanese sophora concentrate (flower bud)],
phosphatidyl-
choline complex [from sunflower]) 15 mg.
Other Ingredients: Microcrystalline cellulose, stearic acid, croscarmellose
sodium, vegetable stearate, silica, coating (hydroxypropyl methylcellulose,
glycerin).
APPROVED
Top Pick
for high dose (500+ mg)
Nature's Bounty® C 500 mg
Mfd. by Nature's Bounty, Inc.
1 tablet
500 mg (ascorbic acid)
✔
Medium circular tablet
Heavy Metals: NA
Disintegration: Pass
For adults, take one (1) tablet up to four times daily, preferably with meals.
$0.04/tablet
[$0.04]
$10.42/250 tablets
Non-GMO, No Artificial Color, No Artificial
Flavor, No Artificial Sweetener, No Sugar, No Starch, No Milk, No Lactose, No
Soy, No Gluten, No Wheat, No Yeast, No Fish, Sodium Free. Suitable for
Vegetarians.
1 tablet
Vitamin C (as Ascorbic Acid) 500 mg.
Other Ingredients: Vegetable Cellulose, Calcium Silicate. Contains <2% of:
Vegetable Magnesium Stearate, Vegetable Stearic Acid.
APPROVED
Nature's Way® Vitamin C With Rose Hips
Dist. by Nature's Way Brands, LLC
1 capsule
1,000 mg (ascorbic acid)
✔
Large capsule
Heavy Metals: Pass
Disintegration: NA
Take 1 capsule as needed, preferably with food.
$0.09/capsule
[$0.04]
$21.43/250 capsules
Gluten Free. No sugar, salt, yeast, wheat, soy,
dairy products, or artificial colors, flavors, or preservatives.
1 capsule
Vitamin C (ascorbic acid) 1 g, Rose Hips 25 mg.
Other Ingredients: Gelatin (capsule), magnesium stearate.
APPROVED
Nutrifii Vinali®ⓘ
Dist. by Ariix
1 capsule
310 mg (calcium ascorbate, acerola cherry, amla fruit extract, green pepper
extract, ascorbyl palmitate)
✔
Large vegetable capsule
Heavy Metals: Pass
Disintegration: NA
Take 1 capsule twice daily, preferably with meals.
$1.10/capsule
[$1.77]
$61.36/56 capsules
1 capsule
Calcium 36 mg, grape seed extract 100 mg, grape skin extract 30 mg, citrus
bioflavonoids 10 mg
NSF® Contents Certified seal.
1 capsule
Vitamin C (calcium ascorbate, acerola cherry, amla fruit extract, green pepper
extract, ascorbyl palmitate) 310 mg, Calcium (as
calcium ascorbate) 36 mg, more...
APPROVED
Rexall® Vitamin C 500 mgⓘ
Dist. by Dolgencorp, LLC
1 chewable tablet
500 mg (ascorbic acid, sodium ascorbate)
✔
Medium/large circular chewable tablet
Taste: Mildly sweet and sour taste with slight orange flavor
(Includes sucrose; 5 Calories per tablet)
Heavy Metals: NA
Disintegration: NA
For Adults, Chew One (1) Tablet Daily, Preferably With A Meal.
$0.07/chewable tablet
[$0.07]
$7.00/100 chewable tablets
1 chewable tablet
Sodium 30 mg
No Gluten, No Yeast, No Wheat, No Milk or Milk Derivatives, No Lactose, No
Soy, No Artificial Flavor.
1 chewable tablet
Calories 5, Total Carbohydrate 1 g, Total Sugars [Includes <1 g Added
Sugars] <1 g, Vitamin C (as Ascorbic Acid and Sodium Ascorbate) 500 mg,
Sodium 30 mg.
Other Ingredients: Sucrose, Cellulose (Plant Origin). Contains <2% of:
Yellow No. 6 Lake, Natural Flavor, Silica, Vegetable Magnesium Stearate,
Vegetable Stearic Acid.
APPROVED
Signature Care™ Vitamin C 500 mg
Dist. by Better Living Brands LLC
1 tablet
500 mg (ascorbic acid)
✔
Medium circular tablet
Heavy Metals: NA
Disintegration: Pass
Take one (1) tablet daily, preferably with a meal or as directed by a
healthcare practitioner.
$0.09/tablet
[$0.09]
$8.99/100 tablets
None.
1 tablet
Vitamin C 500 mg.
Ingredients: Ascorbic Acid, Cellulose (Plant Origin), Calcium Silicate.
Contains <2% of: Croscarmellose Sodium, Magnesium Stearate, Stearic Acid.
APPROVED
Solgar® Vitamin C 1,000 mg
Mfd. by Solgar, Inc.
1 vegetable capsule
1,000 mg (L-ascorbic acid)
✔
Large vegetable capsule
Heavy Metals: NA
Disintegration: NA
As a dietary supplement for adults, take one (1) vegetable capsule up to two
times daily, preferably with meals or a directed by a healthcare practitioner.
$0.12/vegetable capsule
[$0.06]
$30.59/250 vegetable capsules
Kosher. Non-GMO. Gluten, Wheat & Dairy Free.
Suitable For Vegans. Free Of: Gluten, Wheat, Dairy, Soy, Yeast, Sugar, Sodium,
Artificial Flavor, Sweetener, Preservatives and Color.
1 vegetable capsule
Vitamin C (as L-ascorbic acid) 1,000 mg.
Other Ingredients: Vegetable Cellulose, Vegetable Magnesium Stearate.
APPROVED
Sundown® Vitamin C 500 mgⓘ
Mfd. by Rexall Sundown, Inc.
1 tablet
500 mg (ascorbic acid)
✔
Medium circular tablet
Heavy Metals: NA
Disintegration: Pass
For Adults, Take One (1) Tablet One To Two Times Daily, Preferably With Meals.
$0.05/tablet
[$0.05]
$5.39/100 tablets
Vegetarian. Non-GMO. No Gluten. No Wheat. No
Milk. No Lactose. No Artificial Color. No Artificial Flavor. No Artificial
Sweetener. No Sugar. N Soy. No Starch. No Yeast. No Peanuts. No Tree Nuts. No
Fish. Sodium Free.
1 tablet
Vitamin C (as Ascorbic Acid) 500 mg.
Other Ingredients: Vegetable Cellulose, Calcium Silicate. Contains <2% of:
Vegetable Magnesium Stearate, Vegetable Stearic Acid.
APPROVED
Thorne® Vitamin C with Flavonoids
Mfd. by Thorne Research, Inc.
1 capsule
500 mg (ascorbic acid)
✔
Large capsule
Heavy Metals: Pass
Disintegration: NA
Take 1 capsule one to three times daily or as recommended by you healthcare
practitioner.
$0.13/capsule
[$0.13]
$23.00/180 capsules
1 capsule
Citrus bioflavonoids 75 mg.
Gluten Free.
1 capsule
Vitamin C (as Ascorbic Acid) 500 mg, Citrus Bioflavonoids 75 mg.
Other Ingredients: Hypromellose (derived from cellulose) capsule, Silicon
Dioxide.
Gummies, Liquids and Powders:
APPROVED
American Health® Ester-C®
Mfd. by American Health, Inc.
2/3 tsp [2.71 g]
1,500 mg (Ester-C® calcium ascorbate)
✔
Powder in container
Taste: Brown powder; mixed in water, imparts an unpleasant, earthy flavor,
not sour
(10 Cal per 2/3 teaspoon)
Heavy Metals: Pass
Disintegration: NA
For adults, add 2/3 teaspoon (2.71 g) mixed in water or juice once daily,
preferably with a meal.
$0.27/2.71 g
[$0.09]
$22.05/8 oz [226.8 g] bottle (approx. 83 servings)
2/3 tsp
Calcium 200 mg, citrus bioflavonoids complex 150 mg.
No Gluten, No Yeast, No Wheat, No Milk or Milk Derivatives, No Lactose, No
Soy, No Egg, No Corn, No Grapefruit, No Sugar, No Artificial Color, No
Artificial Flavor, No Sodium. Non-GMO. Suitable Vegans.
2/3 tsp
Calories 10, Total Carbohydrate 2 g, Vitamin C (as Ester-C® Calcium Ascorbate)
1,500 mg, Calcium (as Ester-C® Calcium Ascorbate) 200 mg, Citrus Bioflavonoids
Complex [Citrus Bioflavonoids (from Lemon peel) (Citrus limon),
Naturally Occurring Vitamin C Metabolites] 150 mg.
Other Ingredients: None listed.
APPROVED
Emergen-C 1,000 mg Vitamin C -
Super Orangeⓘ
Dist. by Alacer Corp.
1 packet [9.1 g]
1,000 mg (ascorbic acid, zinc ascorbate)
✔
Powder in packets
Taste: Off white powder; mixed in water, imparts an slight orange flavor
that lingers
(35 Cal/packet)
Heavy Metals: Pass
Disintegration: NA
Ages 14 and up, one (1) packet daily.
$0.46/packet
[$0.23]
$13.90/30 packets
1 packet
Thiamin 0.36 mg, riboflavin 0.39 mg, niacin 4 mg, vitamin B6 10 mg, folate 167
mcg DFE, vitamin B12 25 mcg, pantothenic acid 2.5 mg, calcium 50 mg, phosphorus
38 mg, magnesium 53 mg, zinc 2 mg, manganese 0.5 mg, chromium 10 mcg, sodium 65
mg, potassium 200 mg
Caffeine-Free, Gluten-Free, Vegetarian & Natural Sweeteners.
1 packet
Calories 35, Total Carbohydrate 8 g, Total Sugars (Includes 6 g Added Sugars) 6
g, Vitamin C (as ascorbic acid, zinc ascorbate) 1,000 mg, Thiamin (as thiamin
hydrochloride) (Vit. B1) 0.36 mg, Riboflavin (as riboflavin-5'-phosphate) (Vit.
B2) 0.39 mg, Niacin (Vit. B3) 4 mg, Vitamin B6 (as pyridoxine hydrochloride) 10
mg, Folate (Vit. B9) 167 mcg DFE (100 mcg Folic Acid), more...
APPROVED
Garden of Life® mykind
Organics Vitamin C - Organic Spray - Orange-Tangerine
Dist. by Garden of Life LLC
5 sprays [2.1 ml]
60 mg (organic food blend)
✔
Liquid from bottle
Taste: Orange-tangerine flavor (as labeled), slightly tart, slight medicinal
taste
(Includes organic glycerin and apple juice; Calories not listed)
Heavy Metals: Pass
Disintegration: NA
Adults and children 4 years and older, take 5 sprays (or more) daily as needed.
$0.36/5 sprays
[$3.02]
$9.79/2 fl oz [58 ml] bottle (approx. 27 serving)
5 sprays
Certified organic food blend 165 mg
Kosher. USDA Organic seal. Non GMO Project Verified seal. Certified Vegan
Vegan.org seal. Gluten-Free. Contains no artificial colors, flavors, sweeteners
or preservatives.
5 sprays
Vitamin C (from Organic Food Blend) 60 mg, Certified Organic Food Blend
[Organic Amla Berry (fruit), Organic Strawberry (fruit), Organic Tart Cherry
(fruit), Organic Blackberry (fruit), Organic Blueberry (fruit), Organic
Raspberry (fruit), Organic Beet (root), Organic Carrot (root), Organic Spinach
(leaf), Organic Broccoli (stalk & flower), Organic Tomato (fruit), Organic
Kale (leaf), Organic Parsley (leaf), more...
APPROVED
Nature Made® C Gummies 250 mgⓘ
Dist. by Nature Made Nutritional Products
2 gummies
250 mg (ascorbic acid, sodium ascorbate)
✔
Large orange wedge-shaped gummy
Taste: Mildly sweet, very chewy
(15 Cal/2 gummies)
Heavy Metals: NA
Disintegration: NA
Adults, chew 2 gummies daily.
$0.41/2 gummies
[$0.81]
$16.29/80 gummies
2 gummies
Sodium 15 mg
USP Dietary Supplement Verified seal. No Artificial Flavors - Natural Fruit
Flavors. No Synthetic Dyes - Color Derived from Natural Source. No High
Fructose Corn Syrup. No Artificial Sweeteners. Gluten Free.
2 gummies
Calories 15, Total Carbohydrate 4 g, Total Sugars [Includes 2 g Added Sugars] 2
g, Vitamin C (as Ascorbic Acid & Sodium Ascorbate) 250 mg, Sodium 15 mg.
Other Ingredients: Sugar, Glucose, Syrup, Water, Gelatin, Sodium Citrate,
Natural Flavors, Color Added.
APPROVED
Top Pick
for medium to high dose with downward serving adjustment
Solaray® Vitamin C Powder 5,000 mg
Mfd. by Nutraceutical Corp.
1 heaping tsp [5 g]
5,000 mg (ascorbic acid)
✔
Powder in container
Taste: White powder; mixed in water, imparts extreme sour taste
(Calories not listed)
Heavy Metals: NA
Disintegration: NA
Mix one heaping teaspoon (5 g) into water or juice and drink with meals.
$0.28/heaping tsp
[$0.03]
$12.52/8 oz [227 g] bottle (approx. 45 servings)
No Fillers. No Excipients.
1 heaping tsp
Vitamin C (as Ascorbic Acid) 5,000 mg.
Other Ingredients: None.
APPROVED
Vitafusion™ Power C™ - Natural Orange
Flavor
Dist. by Church & Dwight Co., Inc.
3 gummies
282 mg (ascorbic acid, sodium ascorbate, rose hips)
✔
Large orange wedge-shaped gummy
Taste: Mildly sweet, very chewy, slightly tart
(30 Cal/3 gummies)
Heavy Metals: Pass
Disintegration: NA
Adults take three (3) gummy vitamins per day.
$0.62/3 gummies
[$1.10]
$14.46/70 gummies
3 gummies
Sodium 35 mg
No Artificial Flavors or Sweeteners. No Gluten. No High Fructose Corn Syrup.
No Dairy. No Synthetic FD&C Dyes.
Precaution: Processed in a facility with products that contain egg,
fish, shellfish, soy and tree nuts.
3 gummies
Calories 30, Total Carbohydrate 7 g, Total Sugars [Includes 6 g Added Sugars] 6
g, Protein <1 g, Vitamin C (as ascorbic acid, sodium ascorbate, Rose Hips)
282 mg, Sodium 35 mg.
Other Ingredients: Glucose syrup, sugar, water, gelatin; less than 2% of:
citric acid, color (annatto extract), fumaric acid, lactic acid, natural
flavor, and sodium citrate.
Children's Products:
APPROVED
ChildLife® Liquid Vitamin C
Dist. by ChildLife®
1/4 tsp [1.25 ml]
63 mg (sodium ascorbate, ascorbic acid)
✔
Liquid from bottle
Taste: Medicinal tasting, sour
(2.5 Cal/0.25 tsp)
Heavy Metals: NA
Disintegration: NA
Infants 6 - 12 mos: 1/4 tsp daily. Children 1 - 3 yrs: 1/2 - 1 tsp. Children 4+ yrs:
1 - 2 tsp daily.
$0.07/1.25 ml
[$0.54]
$6.36/4 fl oz [118 ml] bottle (approx. 94 servings]
1/4 tsp
Sodium 5 mg
NSF Certified Gluten Free seal. Non GMO Project Verified seal. Alcohol Free.
Casein Free. Contains no milk, eggs, soy, wheat, yeast or corn. No artificial
colors, flavors, or sweeteners.
1/4 tsp
Calories 0, Total Carbohydrates 0 g, Total Sugars [Includes Added Sugars 0 g] 0
g, Vitamin C (as Sodium Ascorbate and Ascorbic Acid) 63 mg, Sodium 5 mg.
Other Ingredients: Purified Water, Fructose, Vegetable Glycerin, Natural
Flavors, Potassium Sorbate (to preserve freshness), Grapefruit Seed Extract.
APPROVED
Natures Plus® Animal Parade® Vitamin C - Natural
Orange Juice Flavor
Mfd. by Natural Organics Laboratories, Inc.
2 chewable tablets
250 mg (ascorbic acid)
✔
Medium/large chewable tablet
Sweet, slightly chalky, slight orange flavor
(10 Cal/2 tablets)
Heavy Metals: Pass
Disintegration: NA
As a dietary supplement for children, two chewable tablets once daily.
$0.20/2 chewable tablets
[$0.40]
$9.01/90 chewable tablets
2 chewable tablets
Bioflavonoid complex 50 mg
Gluten Free. Free from artificial colors and preservatives. Free from all of
the major allergens identified in the U.S. Food Allergen Labeling and Consumer
Protection Act. Vegetarian.
2 chewable tablets
Calories 10, Total Carbohydrate 2 g, Total Sugars [Includes 2 g Added Sugars] 2
g, Vitamin C (as ascorbic acid) 250 mg, Bioflavonoid Complex (from Citrus
limon exocarp) 50 mg.
Other Ingredients: Xylitol, fructose, natural orange flavors, natural flavors,
stearic acid, citric acid, magnesium stearate, natural color (annatto,
curcumin), beet juice and C-Source (proprietary whole food complex, more...
APPROVED
Top Pick
for adults to meet their daily requirements
Solgar® U-Cubes™ Vitamin C
Gummies
Dist. by Solgar, Inc.
2 gummies
250 mg (ascorbic acid)
✔
Medium/large cube-shaped gummy
Taste: Sweet (sugar-coated), chewy, slightly tart, artificial orange or
strawberry flavor
(15 Cal/2 gummies)
Heavy Metals: NA
Disintegration: NA
Children 2 and 3 years of age: Chew two (2) gummies daily or as directed by a
healthcare practitioner. Adults and children 4 years of age and older: Chew
four (4) gummies daily or as directed by a healthcare practitioner.
$0.22/2 gummies
[$0.87]
$9.74/90 gummies
2 gummies
Sodium 10 mg
Non GMO Certified by NSF seal. Gluten Free. Free Of: Gluten, Wheat, Dairy,
Soy, Yeast and made with Natural Flavors.
2 gummies
Calories 15, Total Carbohydrate 4 g, Total Sugars [Added Sugars 3 g] 3 g,
Vitamin C (as ascorbic acid) 250 mg, Sodium 10 mg.
Other Ingredients: Organic Can Sugar, Organic Tapioca Syrup, Pectin, Citric
Acid, Sodium Citrate, Colors Added (Black Carrot Juice Concentrate, Annatto),
Natural Flavors.
Unless otherwise noted, information about the
products listed above is based on the samples purchased by ConsumerLab.com (CL)
for this Product Review. Manufacturers may change ingredients and label
information at any time, so be sure to check labels carefully when evaluating
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ConsumerTips™:
What to
Consider When Buying:
Sources of vitamin C: How important is "Natural"?
Both natural and synthetic vitamin C are equally recognized and used by the
body (as both provide the active "L" form of ascorbic acid), so
"all-natural" rose hips, acerola or camu camu products may not provide any added benefit if you just
want vitamin C.
For example, only about 2% of dried rose hips powder is
vitamin C (in fresh pulp it is about 0.5%), so 500 mg of rose hips powder
contributes only 10 mg of vitamin C, and 10 to 20 mg of rose hips (an amount
commonly listed on vitamin C supplement labels) won't even provide 1 mg of
vitamin C and is likely little more than a marketing hook. In fact, some
products stating "with rose hips" but not indicating the amount of
vitamin C from this source may contain far more synthetic vitamin C than
vitamin C from rose hips. (Hint: A product's ingredient list gives a clue to
the amount of rose hips present. Ingredients must appear in descending order of
amount, from greatest to least. If rose hips appear last, there isn't much in
the product.)
Although only a small part of rose hips is vitamin C, the hips contains many
other compounds, including fiber, and, in sufficient dose, may have other
benefits. A study in Sweden found that giving 40 grams of rose hip powder
(excluding seeds) daily slightly reduced LDL ("bad") cholesterol levels
in obese patients, although it did not help reduce weight and one-third of
patients experienced gastrointestinal effects, particularly loose stools (Andersson, Eur J Clin Nutr 2012).
Only about 1.5% of acerola powder is vitamin C. Some products
may contain concentrated acerola extract, which will have higher amounts of
natural vitamin C (about 6% in the case of a 4:1 extract). Camu camu naturally
has a higher concentration of vitamin C (about 1 to 3% of the fresh pulp --
which is about 30 times that of an orange), and camu camu extract may be as much as 20% vitamin C (i.e., a 400
mg capsule of would provide 80 mg of vitamin C).
Forms of vitamin C: Ester-C® (calcium ascorbate) is a non-acidic
form of vitamin C combined with calcium that may be beneficial for people who
experience symptoms of acid stomach from ordinary vitamin C. Note however, that
diarrhea associated with higher intakes of vitamin C has nothing to do with
acidity. Ester-C® also claims to be better absorbed than regular ascorbic acid,
but this claim has not yet been supported by reliable evidence. A clinical
study (sponsored by NBTY, Inc, the owner of Ester-C) did find, however, that
taking 1,000 mg of vitamin C as Ester-C increased vitamin C levels in the white
blood cells (leukocytes) of volunteers for a significantly longer period (24
hours) than vitamin C as ascorbic acid — even though there was no significant
difference in absorption into blood plasma (Mitmesser, SpringerPlus 2016).
The researchers suggested this may be beneficial to overall immune function
since vitamin C is vital to the function of leukocytes.
Sodium ascorbate is also non-acidic. Products containing sodium ascorbate
combined with ascorbic acid offer reduced acidity and are sometimes called
"buffered vitamin C." (Note that this form contains sodium, which may
be of concern to people watching their sodium (salt) intake).
Slow-release products may also help reduce digestive problems occurring with
very high doses.
Some products list "L-ascorbic acid" — which is the chemical
name for vitamin C. Don't worry if you see "ascorbic acid" without
the "L," as this is an accepted common name for "L-ascorbic
acid." Although an inactive "D" form of ascorbic acid can be
synthetically produced, current manufacturing is based on fermentation,
producing only the only the "L" form of vitamin C. (The situation is
different with synthetic vitamin E, in which the
inactive form is found along with the active form in supplements.)
Ascorbyl palmitate is a fat-soluble form of vitamin C
that is often found in softgels.
Some vitamin C products claim to be "fully reduced;" however, if
properly manufactured and stored, vitamin C is already in a fully reduced
state, so there is no reason to seek out or pay more for products making this
claim.
Liposomal vitamin C is vitamin C that has been
encapsulated by a microscopic layer of phospholipids, or fats. Liposomal
technology was developed as a drug delivery system to help protect ingredients
in the gastrointestinal system and enhance absorption through cell membranes.
However, there is limited research to-date on the use of liposomes with vitamin
C. A study of just two people found, at a 5 gram dose of vitamin C, no better
absorption with a liposomal vitamin C (Lypo-Spheric,
LivOn Labs) than with non-liposomal vitamin C (Hickey, J Nutri Envir
Med 2008). At much larger doses (20 grams and 36 grams of vitamin
C), liposomal vitamin C absorption exceeded the maximum absorption expected
based on previous research on non-liposomal vitamin C; however, oddly, no
direct comparison was made to the non-liposomal form. The amounts of vitamin C
used were intentionally extremely high as the study was based on a premise that
such doses might be useful in cancer therapy — although this has not been
demonstrated and could have risks. Liposomal vitamin C can cost
significantly more than other forms of vitamin C -- around 50 cents per 500 mg,
versus just a few cents. Due to the dearth of evidence suggesting a
benefit, it does not seem worth spending more for liposomal vitamin C,
particularly if you are taking a dose of 5 grams or less. (If
you have a soy allergy, be aware that the phospholipids used in Lypo-Spheric are made from soy lecithin. LivOn Lab's website states that
they cannot guarantee that their products do not contain trace amounts of soy
protein, although their allergen testing has not detected any amounts of soy
protein in their products.)
A study of a formulation of vitamin C combined with fatty acids (PureWay-C, Innovation Labs) found that, after
four hours, absorption from a single one gram dose was similar to that from one
gram of ascorbic acid without fatty acids, as well as to a one gram dose of
Ester-C® (calcium ascorbate) (Pancorbo, Med Sci Monit 2008).
Bioflavonoids: Some vitamin C supplements, including
several in this Review, include various bioflavonoids as ingredients. These
bioflavonoids may come from citrus fruit (such as lemon) and other sources,
such as buckwheat, and include compounds such hesperidin, quercetin, and rutin. Bioflavonoids are believed to work synergistically
with, and increase the absorption of vitamin C. Much of this belief is based on
a small study from 1988 suggesting that citrus bioflavonoids increased the
bioavailability of vitamin C by 35%. This study also found that the
bioflavonoids slowed the release of vitamin C, presumably extending the benefits
of each dosage (Vinson, Am J Clin Nutr 1988). While these results were promising,
they have yet to be confirmed by other studies.
Preliminary evidence suggests that bioflavonoids may have therapeutic value
independent of their relationship with vitamin C, such as in the treatment of
hemorrhoids, venous insufficiency, and leg ulcers (Giannini, Tech Coloproctol 2015).
The combination of vitamin C (as ascorbic acid) and a particular bioflavonoid
called dihydroquercetin has been studied in Russia.
Russian researchers have characterized the combination as a powerful
antioxidant with applications ranging from ischemic disease to cancer
prevention. Unfortunately, none of the research has been replicated outside of
the Russian Federation, so the true benefit of this combination remains
unclear.
Although bioflavonoids have been shown to function as antioxidants in the
laboratory, this may not be how they act in the body. A typical clinical dosage
of citrus bioflavonoids is 500 mg twice daily. None of the products in this
Review provide this amount of total bioflavonoids in a daily suggested serving,
and be aware that if bioflavonoids are listed as a "bioflavonoid complex",
you may not be able to determine how much of the "complex" is
actually bioflavonoids.
What to Consider When Using:
When looking for a dosage of vitamin C, be aware that 1,000 mcg (micrograms) equals
1 mg (milligram), and 1,000 mg equals 1 gram. The RDA (Recommended Dietary
Intake) for vitamin C is 90 mg/day for adult males and 75 mg/day for adult
females. An additional 35 mg/day is recommended for smokers. For pregnant women
ages 18 and younger, the RDA is 80 mg/day and for pregnant women older than age
18, it's 85 mg/day. For breast-feeding women ages 18 years and younger, the RDA
is 115 mg/day and for breast-feeding women older than age 18, it's 120 mg/day.
The RDAs for children are as follows: 15 mg/day for children ages 1 to 3, 25
mg/day for children ages 4 to 8, and 45 mg/day for children ages 9 to 13. For
males ages 14 to 18, the RDA is 75 mg/day. For females ages 14 to 18, it's 65
mg/day.
The RDAs for vitamin C are achievable with healthful diet and
are also more than adequate for normal collagen production. Some common
foods rich in vitamin C are raw sweet peppers (95 mg per ½ cup),
tomato juice (33 mg per ¾ cup), one medium kiwifruit (64 mg), one medium orange
(70 mg), grapefruit (70 mg per ¾ cup), orange juice (93 mg per ¾ cup), broccoli
(51 mg per ½ cup, cooked), Brussels sprouts (48 mg per ½ cup, cooked), and
cauliflower (26 mg per ½ cup, raw) (National Institutes of Health 2020).
The amount of vitamin C that may be helpful for reducing the symptoms and
duration of a cold if taken routinely during cold season is, in adults, 1,000
mg, taken as 500 mg twice a day. A similar dosage is used to help prevent colds
when taken for a period of weeks prior to an endurance event.
Vitamin C interference with statins?
Concerns were raised that vitamin C might decrease the effects of statin
medications by a study in people with heart disease and low HDL cholesterol
which showed that taking vitamin C (1,000 mg per day) along with other
antioxidants (800 IU of vitamin E (as d-alpha-tocopherol), 25 mg of natural
beta carotene, and 100 mcg of selenium) reduced the cholesterol-lowering
effects of the statin medication simvastatin (Zocor) taken in
combination with high-dose niacin (2,000 mg) (Cheung, Arterioscler Thromb Vasc Biol 2001).
However, it is not clear if this effect was due to vitamin C or one of the
other antioxidant supplements taken, or whether this would occur if taking
simvastatin without high-dose niacin, or when taking other statin medications.
Currently, prescribing information for simvastatin, atorvastatin (Lipitor),
lovastatin (Mevacor, Altoprev)
and rosuvastatin (Crestor) does not note an interaction with vitamin C, but
does warn against taking high-dose niacin (> 1,000 mg per day), as this is
now known to increase the risk of adverse skeletal muscle effects such as
muscle pain or breakdown and leakage of muscle tissue (rhabdomyolysis), a
condition that can be life-threatening. (For more information about high-dose
niacin and cholesterol, see the B Vitamin Supplements Review).
Concerns and Cautions:
·
Vitamin C is safe when taken in moderate amounts, but be aware
that too much vitamin C can cause diarrhea and other gastric
disturbances, such as heartburn. Keep in mind that unless you are taking a
buffered form of vitamin C (such as calcium ascorbate or sodium ascorbate),
vitamin C is acidic. To reduce gastric side effects, divide the dose over the
course of day and take with meals. The Upper Tolerable Intake Level (UL) (i.e.,
the maximum daily amount likely to be safe for the vast majority of healthy
people) for vitamin C in adults is 2,000 milligrams — based on total intake
from foods, beverages, and supplements. The upper level for tolerable intake is
400 mg/day for children ages 1 to 3, 650 mg/day for children ages 4 to 8, 1,200
mg/day for children ages 9 to 13, and 1,800 mg/day for teens ages 14 to 18
ages. Individuals are generally advised not to exceed these levels unless under
medical supervision.
·
Daily use of high-dose vitamin C supplements may increase the
risk of cataracts. An eight-year Swedish study of 25,593 women showed a 25%
increase in cataract removals among those taking vitamin C supplementation
(approximately 1,000 mg per day) compared to those who did not. Women taking
vitamin C supplements for at least 10 years prior to the study had even higher
increases in cataract removals (46% increase).
·
Concerns have been raised that vitamin C supplementation may
increase the risk of kidney stones, which can cause difficulties with
urination. Although not all studies have found an association, two population
studies in men found the risk of developing stones to be higher among those
taking vitamin C supplements compared to those not taking vitamin C: A study in
Sweden found in the risk to be 66% higher for men taking an estimated 1,000 mg
of vitamin C occasionally, and 123% higher for those taking it seven or more
times each week (Thomas, JAMA 2013); and
a study in the U.S. found the risk to be 16% higher among men consuming 1,000
mg or more per day of vitamin C from supplements (Taylor, J Am Soc Nephrol 2004). Case reports
and small clinical studies suggest that certain individuals may be at increased
risk for developing kidney stones if they supplement with large amounts
(typically a gram or more daily) of vitamin C due to the conversion of
ascorbate (from vitamin C) to oxalate, forming calcium oxalate crystals. These
crystals can irritate and injure the urinary tract, causing blood to appear in
the urine (Auer, Eur Ju Clin Invest 1998). Vitamin C may
also increase oxalate absorption from foods. For this reason, people with a
history of kidney stones, or those with known defects in metabolism of oxalate
or vitamin C, might be best advised to limit vitamin C intake from supplements
to RDA levels or no more than 250 mg per day (Massey, Frontiers in Bioscience, 2003, pp. 585-6).
·
Vitamin C intake greater than 2,000 mg per day may cause oxalate
crystal nephropathy, a condition in which oxalate crystals are deposited in
the tubules and tissue of the kidney, leading to kidney damage and/or
kidney failure. This may be more likely to occur in people who have a high
intake of oxalate-rich foods, and in people with certain medical conditions,
such as pre-existing kidney disease, pancreatic insufficiency, bowel
inflammation, celiac disease or an enlarged prostate. For example, high
oral doses of vitamin C (1,000 mg to 2,000 mg) in man in his 80's who had
pancreatic insufficiency (a condition that, due to fat malabsorption, allows
oxalate to be absorbed in the colon) were implicated in the development of
oxalate nephropathy and end stage kidney disease that required dialysis (Fijen, BMJ Case Rep 2019).Oxalate crystal nephropathy and
kidney injury were also reported in a 69-year-old man who had been taking 2,000
mg of vitamin C daily for two years. The man also had benign prostatic
hyperplasia (BPH) which may have contributed to the crystal deposition in the
kidneys. However, other cases have been reported in individuals taking daily
doses of vitamin C as low as 480 mg per day, with onset occurring after one
month to several years of supplementation (Lin, CEN Case Rep 2018).
·
Some people with interstitial cystitis report that vitamin C, as
well as citrus products, cause irritation (Friedlander, BJU Int 2012).
·
Another study suggests that high dose vitamin C might reduce the
effectiveness of the HIV drug indinavir.
·
Vitamin C may also interfere with the absorption of tricyclic
antidepressants and anticoagulants.
·
Excess vitamin C from supplements can interfere with diagnostic
tests for cholesterol and sugar levels in the blood, as well as for
blood in the stool.
·
The risk of liver damage from high doses of acetaminophen
(Tylenol®) may be increased if you also take large doses (3 grams) of
vitamin C.
·
Because vitamin C improves iron absorption, people
with diseases that cause them to store too much iron should use vitamin C only
with caution.
·
High doses of vitamin C may modestly decrease copper
levels in the body: For example, young healthy men who took a 500-mg
tablet of vitamin C three times per day (1,500 mg total daily) for two months
experienced significantly reduced activity of a protein that stores and
transports copper in the body (ceruloplasmin). Their blood levels of copper
also decreased but the change was not statistically significant (Finely, Am J Clin Nutr 1983).
Another study found that lower doses of vitamin C (5 mg to 635 mg per day)
taken for one month did not decrease blood levels of copper, although the
635-mg dose did decrease the activity of ceruloplasmin (Jacob, J Nutr 1987).
·
There is test-tube (in-vitro) evidence that vitamin C may cause
the production of DNA-damaging genotoxins that promote the
development of cancer — arguing against high dose vitamin C as a way to reduce
cancer risk.
·
One study found that taking vitamin C along with Pycnogenol (an extract of pine bark, also known
as OPCs or oligomeric proanthocyanidins) might raise
blood pressure levels in people with hypertension. The reasons for this
unexpected finding are currently unclear.
·
High daily doses of vitamins C and E each seem to hamper
beneficial changes which occur during endurance and resistance
(strength) training. A study among healthy young women in Brazil who
participated in a 10-week strength training program found that those who took
1,000 mg of vitamin C plus 400 IU of vitamin E (a-tocopherol) daily did
not experience significant increases in muscle (fat-free mass) while
those who, instead, took a placebo experienced increases in muscle as well as a
decrease in fat-free mass. The researchers concluded that "vitamin C and E
supplementation should be avoided by healthy young women who want to increase
fat-free mass." (Maurilio, Int J Exerc Sci 2019). Similarly,
an 11-week study in Norway found that young men and women who trained (running
and cycling) 3 to 4 times per week increased mitochondrial proteins thought to
be important for improving muscular endurance. However, this change did not
occur among those given 500 mg of vitamin C (from ascorbic acid) or 117 mg (260
IU) of synthetic vitamin E before and after training, and in the morning and
evening when not training. Overall performance, as measured by oxygen use (VO2max) and a running test, however, improved
equally among those who received or did not receive supplementation (Paulsen, J Physiol 2014).
The authors note that a similar study using only half the daily dose of vitamin
C did not find a blunting of biochemical changes. The authors advise caution
when considering high-dose antioxidant supplementation with endurance training.
A similar concern has been raised with resveratrol supplementation.
·
Another study in Norway tested the same high-dose vitamin C/ E
combination on healthy elderly men who underwent strength training for 12
weeks. The vitamins were expected to result in greater benefits to the
skeleton, but this did not happen. Bone density in the lower
back increased more among men given a placebo than the vitamins, and bone
density in the hip only increased in the placebo group. The researchers
concluded that high doses of antioxidants may constrain the favorable benefits
of resistance exercise (Stunes, Eur J Applied Phys 2017).
Information on this site
is provided for informational purposes only. It is not an endorsement of any
product nor is it meant to substitute for the advice provided by physicians or
other healthcare professionals. The information contained herein should not be
used for diagnosing or treating a health problem or disease. Consumers should
inform their healthcare providers of the dietary supplements they take.
Latest Clinical Research Updates for Vitamin C
Vitamin C Serums for Wrinkles?
11/23/2021
Can applying vitamin C to
the skin reduce wrinkles or help prevent sun damage? Find out in the Skin Health section of our Vitamin C
supplements review.
Also learn what features you should look for if selecting a vitamin C
serum.
9/17/2021
Can taking high-dose
vitamin C improve liver function or insulin resistance in people with NAFLD
(non-alcoholic fatty liver disease)? Find out what a recent study showed in
the What It Does section of our Vitamin C
Supplements Review. Also see our Top Picks among vitamin C supplements.
9/05/2021
Does taking vitamin C
reduce the cholesterol-lowering effects of statins? Find out in the What to Consider When Using section of
our Vitamin C Supplements Review.
2/03/2021
Does vitamin C
supplementation reduce the tendency for gums to bleed? Find out what research
shows in the What It Does section of our Vitamin C
Supplements Review. Also see our Top Picks for vitamin C.
High-Dose Vitamin C for COVID-19?
1/13/2021
Does high-dose vitamin C
help in people with severe COVID-19? See what a new study showed in the COVID-19 section of
our Vitamin C Supplements Review.
Related CL Answers (48)