What\u2019s the difference between calcium carbonate, orotate, citrate, and coral calcium? Do some work better than others? Read on to get a quick overview of the advantages and drawbacks of each form of calcium.<\/p>\n
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Calcium<\/a> is the most abundant mineral in the human body and accounts for about 1-2% of its weight. Each and every cell – in the bones, heart, muscles, and nervous system – need it to function properly [R<\/a>, R<\/a>].<\/p>\n Like most earth metals, calcium naturally builds various salts. Let\u2019s dive into basic chemistry for a moment to understand why.<\/p>\n As a mineral, calcium easily becomes charged. It turns into Ca2+<\/sup> – it has two positive charges. This ionic form of calcium is attracted to various negatively charged molecules – including the different forms we\u2019ll discuss in this article: carbonate, citrate, lactate<\/a>, and gluconate.<\/p>\n Unlike the ionic form, calcium salts are stable and lack electrical charge. Some are found in nature, while others are synthetically created in the lab.<\/p>\n Each calcium salt differs in the amount of pure or elemental calcium<\/em> it provides. Calcium salts can also vary in how well they are absorbed, how they taste, and how easily they dissolve in water.<\/p>\n Calcium carbonate<\/a> is the most common calcium compound in the world. It is found in rocks, particularly limestone, as well as in pearls, seashells, and eggshells. In fact, the typical eggshell is about 94% calcium carbonate [R<\/a>, R<\/a>].<\/p>\n Most supplement manufacturers opt in to use calcium carbonate over other salts due to its widespread availability, low price, and extensive medical research. Plus, it contains 40% of elemental calcium, the<\/strong> highest of any calcium salt<\/strong> [R<\/a>].<\/p>\n On the downside, calcium carbonate is poorly absorbed<\/strong>: only about 20% will pass into the bloodstream from the gut [R<\/a>].<\/p>\n In addition, calcium carbonate requires an acidic environment to properly dissolve. Thus, people with low stomach acid due to gut problems or those who take medications for acid reflux (histamine<\/a>-2 blockers and proton-pump inhibitors) will have even more trouble absorbing it [R<\/a>, R<\/a>].<\/p>\n Another disadvantage is its low solubility in water<\/strong>. As a result, calcium carbonate powder can\u2019t be dissolved in water or juice and taken as a drink [R<\/a>, R<\/a>].<\/p>\n Calcium citrate is a complex of calcium and citric acid.<\/p>\n Around 40% of calcium citrate is absorbed<\/strong>, which is at least two-fold better than calcium carbonate<\/strong>. People with low stomach acid will absorb it much easier than carbonate [R<\/a>].<\/p>\n Another advantage of the citrate form is its greater solubility in water<\/strong>. Calcium citrate powder is easy to mix with water and take as a drink, which offers options to people who want to (or need to) avoid large capsules or tablets [R<\/a>, R<\/a>].<\/p>\n Calcium citrate might also be the right choice for people who are prone to kidney stones<\/strong>. Citrate salts can reduce the formation and growth of the most common type of kidney stones (oxalic acid stones) [R<\/a>].<\/p>\n It only contains 21% of elemental calcium, less than calcium carbonate<\/strong> [R<\/a>].<\/p>\n Though not technically a salt, hydroxyapatite is a popular form of calcium in supplements. Hydroxyapatite is a mineral complex<\/strong> that naturally contains calcium and phosphate<\/strong>. It is used to store calcium in the teeth and bones, making up to 70% of the weight of the bones. Hydroxyapatite also contains varying amounts of magnesium<\/a> and trace elements [R<\/a>, R<\/a>].<\/p>\n Nowadays, hydroxyapatite is used in medicine to make biocompatible implants or bone transplants [R<\/a>, R<\/a>].<\/p>\n In a trial on 100 postmenopausal women, hydroxyapatite was as beneficial as carbonate or citrate for preventing bone loss. But interestingly, hydroxyapatite raised blood calcium levels less than both carbonate and citrate<\/strong>. This could mean that hydroxyapatite is more effective at getting into bone cells – where calcium belongs [R<\/a>].<\/p>\n Combining calcium hydroxyapatite with ossein may be a better solution than hydroxyapatite alone. Ossein is a substance that makes bones flexible and is mostly made up of collagen<\/a>. According to a review of clinical studies, this combination is more effective than calcium carbonate at preventing bone loss [R<\/a>].<\/p>\n A trial with 107 people found that chewing gum with calcium hydroxyapatite reduced tooth sensitivity. Many people suffer from sensitivity, often worsened by cold<\/a> foods and drinks. If you\u2019re one of them, chewing gum with hydroxyapatite might help [R<\/a>].<\/p>\n Studies on supplemental calcium hydroxyapatite are few.<\/p>\n In sum, calcium hydroxyapatite may be more effective than other forms, but the evidence is still too weak to justify its hefty price tag<\/strong>.<\/p>\n Calcium lysinate is a salt of calcium and the amino acid lysine<\/a>.<\/p>\n Calcium lysinate might be superior to both carbonate and citrate. In 24 people with bone disease, calcium lysinate was more effective<\/strong> than carbonate and citrate at raising calcium levels. Even more importantly, the lysinate form improved bone density to a greater extent [R<\/a>].<\/p>\n This salt provides 30% of elemental calcium<\/strong>. According to one trial, its absorption rate reaches an astounding 89%<\/strong>, more than double that of any other form. Additionally, L-lysine enhances calcium absorption<\/strong> from the gut while preventing the loss of calcium in the kidneys [R<\/a>].<\/p>\n Unfortunately, calcium lysinate supplements are still not widely available<\/strong>.<\/p>\n Might be similar to calcium carbonate.<\/p>\n Coral and oyster shell calcium have become increasingly popular. Manufacturers claim that coral calcium will promote good health, improve your sleep<\/a>, and even \u201cmake your body more alkaline<\/a>.\u201d Much of the hype is due to a myth about the people who live in the Okinawa region of Japan, where the corals grow. Companies started spreading an appealing story: people living in Okinawa have the longest lifespan and the lowest rates of cancer and other chronic diseases because they regularly drink \u201ccoral water.\u201d No evidence supports such claims.<\/p>\n Both coral and oyster shell calcium are simply calcium carbonate<\/strong> with a sophisticated name and a matching price tag. What\u2019s worse, reports indicate these \u201cnatural sources\u201d of calcium are likely to be heavily contaminated with lead [R<\/a>, R<\/a>, R<\/a>].<\/p>\n Companies make bold claims about calcium orotate. Some state that it\u2019s the single most effective and most highly absorbed form of calcium.<\/p>\n Most of these claims cite the highly controversial research of the late 20th-century doctor Hans A. Nieper, a German practitioner who claimed to treat cancer and other serious diseases with alternative medicine. Nieper is best known for his research on lithium<\/a> orotate<\/a>. His approach goes under various names, from \u201cNieper therapy\u201d to \u201cmetabolic supplementation\u201d [R<\/a>, R<\/a>, R<\/a>, R<\/a>].<\/p>\n Nieper considered that orotate is the most efficient and far-reaching carrier for minerals like calcium and magnesium in the body.<\/p>\n He also patented AEP calcium<\/strong> (calcium aminoethyl phosphate). Although the body uses phosphorylethanolamine – a compound of AEP calcium – to build cells (and their phospholipids), it\u2019s unclear if AEP calcium has any benefits. Studies with this chemical are nonexistent [R<\/a>, R<\/a>].<\/p>\n Additionally, no studies to date have investigated calcium orotate<\/strong> (or AEP calcium). Its safety and efficacy are unknown. Orotate is known to promote tumors in animals. The European Food Safety Authority (EFSA) considers all orotate salts unsafe. Avoid this form<\/strong> [R<\/a>].<\/p>\n Other forms of calcium salts are available, such as calcium gluconate and calcium <\/strong>lactate<\/strong><\/a>. Both contain little calcium and are not well-researched<\/strong>. They are also more expensive, making them a less practical supplement choice [R<\/a>].<\/p>\n In a trial on 43 patients with high blood fat levels, calcium lactate (510 mg\/day) decreased total cholesterol<\/a> levels by 4% without altering blood calcium levels or causing any side effects [R<\/a>].<\/p>\n Most adults need at least 1,000 mg of calcium per day. Women over 50 years need a bit more, 1,200 mg a day. Teenagers, pregnant and breastfeeding women should get at least 1,300 mg calcium per day [R<\/a>].<\/p>\nSnapshot<\/span><\/h3>\n
Good options<\/h4>\n
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Lacking evidence<\/h4>\n
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Possibly dangerous<\/h4>\n
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Calcium Salts Overview<\/span><\/h2>\n
1) Calcium Carbonate<\/span><\/h3>\n
Proponents<\/h4>\n
Skeptics<\/h4>\n
2) Calcium Citrate<\/span><\/h3>\n
Proponents<\/h4>\n
Skeptics<\/h4>\n
3) Hydroxyapatite<\/span><\/h3>\n
Proponents<\/h4>\n
Skeptics<\/h4>\n
4) Calcium Lysinate<\/span><\/h3>\n
Proponents<\/h4>\n
Skeptics<\/h4>\n
5) Oyster Shell & Coral Calcium<\/span><\/h3>\n
Proponents<\/h4>\n
Skeptics<\/h4>\n
6) Calcium Orotate & AEP Calcium<\/span><\/h3>\n
Proponents<\/h4>\n
Skeptics<\/h4>\n
Other Salts<\/strong><\/span><\/h3>\n
Calcium Supplement Dosage<\/span><\/h2>\n
Understanding Your Daily Needs<\/span><\/h3>\n