The Best Calcium Supplement
The best calcium supplement should be independently certified for accuracy and purity. It should include vitamin D to aid in absorption, and it should rely on a form of calcium that's easy for your body to process — like calcium citrate. To find the best, we talked to doctors and consulted clinical research, and then checked out 11 finalists for ourselves to see which were the most palatable.
We loved these calcium citrate caplets for being small and easy to swallow, versus the large, chalky pills offered by many of our finalists. Citracal retails for an affordable $0.21 per serving and comes highly recommended by third-party testing group ConsumerLab.
In addition to calcium citrate and vitamin D, this premium supplement includes herbal additives like boron and horsetail to promote bone health. But it’s pricy, at $0.47 per serving.
A fruit-flavored gummy that’s a tasty alternative to swallowing pills, but must be taken with a meal for full effect. ($0.14 per serving)
The Best Calcium Supplement
Calcium is the most abundant mineral in the body and is essential for building and maintaining strong bones and teeth. It also plays a vital role in keeping your muscles, nerves, and heart functioning normally. As with other nutrients, it’s always best to get your calcium from food first, but this can sometimes be challenging — especially for women as they age.
Do men need calcium supplements? According to the Mayo Clinic, men generally do not need calcium supplements. Men have a much lower risk of osteoporosis than women, whose bodies tend to absorb less dietary calcium as they age.
Our top pick, Citracal Petites Calcium Citrate Formula + D3, has an affordable $0.05-per-pill price point and high ratings from third-party testing group ConsumerLab, which reports that the formula is both pure and accurately labeled. Unlike most of the supplements we tested, Citracal relies on calcium citrate, a form of calcium that doesn’t need to be taken with food. It also includes vitamin D, which aids in the absorption of calcium. A bottle of 200 pills retails for about $11.
Rainbow Light Calcium Citrate Mini-Tablets are a bit pricier ($0.08 per pill). Like Citracal, they include calcium citrate plus a moderate amount of vitamin D. Rainbow Light also goes a step further, including natural additives like spirulina, horsetail, and boron. These ingredients aren’t must-have, but some studies suggest they can help improve bone health. Rainbow Light comes highly rated from third-party testing group LabDoor, although its levels of calcium and vitamin D slightly exceed the claims on its label — $10 for 120 tablets.
If you have trouble swallowing pills, we’d suggest Vitafusion Calcium Gummies as an alternative. These fruit-flavored gummies were the tastiest of all the chews we tested. They rely on tricalcium phosphate, which is a little harder for your body to absorb than calcium citrate, so you should take them with a meal for full effect. Vitafusion passed LabDoor’s third-party testing, although its calcium levels moderately exceed label claims. A bottle of 100 gummies is about $7 (or $0.14 per serving).
How We Found the Best Calcium Supplement
We started our search with all the calcium supplements we could find from popular retailers like Amazon, Target, Walgreens, and Costco. Because calcium will compete for absorption with many other minerals, we avoided looking at multivitamins — if you need a calcium supplement, it’s best to take it on its own. Even so, we were left with a starting list of 258 contenders.
Third-party testing was a must.
If you buy a calcium supplement, you want the dosage information and the ingredients listed on the label to match with what’s actually in your pills. But the Food and Drug Administration doesn’t monitor any of this — instead leaving it up to manufacturers to maintain the integrity of their own products. So it’s important to look for supplements that have been tested by reputable third-party labs. These groups check for things like contaminants and proper labeling. The testing group Labdoor, for example, found that some calcium supplements had up to 42.5 percent less calcium than advertised.
So we only considered supplements that had been approved by one of these groups:
- Consumer Lab - A leading provider of independent test results for health and nutrition products.
- United States Pharmacopeial Convention (USP) – A scientific nonprofit organization that tests medicines and food supplements.
- Labdoor – An independent company that focuses on testing dietary supplements.
- NSF International – An international organization that sets standards for consumer product safety.
A perfect match: Calcium and vitamin D.
In order for your body to properly absorb calcium, it’s important that you’re also getting enough vitamin D. And most people aren’t. A 2009 study found that three-quarters of US adults were vitamin D deficient, and the National Institutes of Health (NIH) reports that older adults are at particular risk.
So why is vitamin D so important? The NIH explains that without vitamin D, the human body is unable to form a hormone called calcitriol, which makes it hard to absorb calcium from dietary sources. Instead, your body will start to use up calcium stored in the skeleton — which weakens your existing bone structure. So we cut any products that didn’t include both calcium and vitamin D.
But we nixed supplements with magnesium and vitamin K
Vitamin D isn’t the only nutrient that helps your body use calcium effectively. Dr. Carolyn Dean, medical advisory board member of the Nutritional Magnesium Association, points out that it’s also important to maintain proper levels of vitamin K2 and magnesium; these work synergistically with calcium.
But it’s not necessarily a good idea to bundle these nutrients together with your calcium supplement. Calcium and magnesium can compete with each other for absorption if taken at the same time, and vitamin K poses a similar problem, competing with vitamin D. If you’re worried about getting enough of these nutrients, we’ve got some tips below for how to add them to your diet. But for a calcium supplement, we’d suggest avoiding these add-ons.
Next, we did a little hands-on testing.
This left us with 13 products. So we took an up-close look at each of our finalists:
- Size: How large were the supplements? While calcium is a bulky mineral, we looked for pills that were still small enough to swallow comfortably.
- Smell: Most of our finalists didn’t have a strong smell. But Nature's Bounty Calcium Plus Vitamin D3 and Schiff Super Calcium were the exception, with off-putting, fishy odors that we couldn’t get past.
- Packaging: Since calcium deficiency can lead to decreased hand strength, we double-checked that all bottle tops were easy to open.
Supplements that were particularly large (Nature’s Bounty, left) or hard-edged (Nature Made, right) didn’t do well during testing.
Our Picks for the Best Calcium Supplement
Citracal first caught our eye because it provides calcium in the form of calcium citrate. This form of calcium is pricier for manufacturers to source, so you won’t see it as often on ingredient labels. In fact, of our 13 finalists, only 2 — Citracal, and runner-up Rainbow Light — got their calcium solely from calcium citrate.
But research suggests it’s also the form that’s easiest for your body to absorb. In fact, a study from the US National Library of Medicine concluded that calcium citrate’s absorption rate was 22 to 27 percent higher than the much more common calcium carbonate. Calcium citrate can also be taken without a meal: Because it’s acidic, your stomach can easily break it down and process it. Non-acidic forms of calcium need the help of stomach acid (which your body only produces when you eat) to be fully absorbed.
Citracal also stood out for being easy to swallow. Calcium in any form is a bulky mineral, so most of the pills we tested were quite large. Nature Made, for example, offered thick tablets with pronounced edges that felt likely to stick doing down, while Nature’s Bounty’s pills were so large we weren’t sure we could swallow them. But Citracal comes in smooth, slender caplets roughly the size of a Tylenol. Each pill delivers a respectable 200 mg of calcium and 250 IUs of vitamin D.
This product also passed ConsumerLab’s third-party testing with flying colors (in fact, it’s one of their top calcium supplement recommendations) — and despite its use of a premium form of calcium we were fans of its affordable $0.05-per-pill price point.
Rainbow Light Mini-Tablets are very similar to Citracal. They, too, rely on calcium citrate, with each pill providing 200 mg of calcium and 200 IUs of vitamin D. They have a mild herbal odor, though we didn’t find it unpleasant.
But unlike our top pick, Rainbow Light’s tablets are food-based, meaning that their nutrients are sourced from whole foods rather than being synthetically produced. There’s no clinical evidence to suggest that food-based supplements are superior, but some people prefer this option based on the theory that nutrients work together synergistically in their natural state and are less potent when created synthetically.
This natural pick also includes the herbal additives horsetail and spirulina, which studies have suggested may help reduce the risk of osteoporosis thanks to their bone-strengthening qualities. Also present is boron, a mineral similarly thought to improve bone strength.
Rainbow Light received a respectable 75 out of 100 from third-party testing group Labdoor. This supplement does come with a slightly higher price tag than Citracal, at $0.08 per pill. But if you’re looking for an all-natural option, it’s our favorite.
If you just can’t handle pills, no worries — we also tested a number of chews. Our pick is Vitafusion Calcium Gummies. At $0.07 per gummy, this option is priced comparably to our other top picks. Each gummy offers 250 mg of calcium and 500 IUs of vitamin D. Vitafusion’s “natural fruit and cream” flavor reminded us pleasantly of Creme Lifesavers, and we preferred Vitafusion to options like Nature Made Adult Calcium Gummies, which we found overpoweringly sweet — or Nature’s Way Alive, which had a strong medicinal scent. Vitafusion gummies do leave a faintly chalky aftertaste behind, but this was true of all the options we tried.
It’s important to note that none of the chewable supplements we tested contained calcium citrate. This means that all of them, including Vitafusion, should be taken with a meal (although many manufacturers claim that this isn’t necessary). Vitafusion uses tricalcium phosphate — an option that didn’t receive as much ire from our experts as calcium carbonate (which Dr. Dean told us she never recommends). But it’s still less absorbable than calcium citrate.
Vitafusion also contain 3 grams of sugar per gummy — chewable options will never be quite as healthy as just swallowing a pill. But it received the highest third-party rating of all our gummy finalists, a 66 out of 100 from Labdoor (who dinged it for having calcium levels that moderately exceeded label claims).
Did You Know?
How much calcium do you need?
Most health organizations, including the Mayo Clinic, suggest that women ages 19-50 should shoot for 1,000 mg of calcium a day, while women aged 51 and older should aim for 1,200 mg of calcium a day.
But despite this high daily allowance, calcium supplements should always be taken in doses of 500 mg or less. Dr. Keith Kantor, CEO of the nutrition initiative NAMED, explained that there’s only so much of the nutrient that our bodies can absorb at one time. He suggests taking half your needed calcium in the morning, and the other half at night.
Should I be worried about additives and fillers?
While researching calcium supplement additives, we ran into some controversy surrounding artificial colors and fillers, especially titanium dioxide and magnesium stearate, which have been linked to health concerns in high doses. We reached out to Morgan Statt, a health and consumer safety advocate at Consumersafety.org, for some help getting to the bottom of the issue. Her take? Don’t be alarmed by these ingredients. She stressed that the health concerns linked to titanium dioxide and magnesium stearate tend to arise from overdoses. In fact, a European research panel found no adverse risks from ingesting titanium dioxide at all, while the US National Institutes of Health report that magnesium stearate toxicity is “very rare.”
Magnesium and vitamin K are also important.
As we learned from Dr. Dean, if you’re concerned about bone health, don’t overlook the importance of magnesium and vitamin K. Magnesium works synergistically with vitamin D and calcium by stimulating the specific hormone calcitonin—which helps to preserve bone structure and draws calcium out of the blood and soft tissues back into the bones, preventing osteoporosis, some forms of arthritis and kidney stones. Magnesium aids in the transport of calcium and potassium ions across cell membranes. This process is critical for nerve impulse conduction, muscle contraction, and normal heart rhythm. Vitamin K, meanwhile, is needed in order for calcium to build bone.
If you’d like to add more vitamin K and magnesium-rich foods to your diet, here are a few suggestions to start you off:
Swiss chard, raw
*Source: USDA Food Composition Databases
Calcium from whole foods is still best.
Calcium supplements aren’t without controversy. There is some evidence to suggest that excessive levels of calcium can increase the risk of heart disease, and most health professionals recommended calcium from dietary sources first. And remember that milk isn’t your only option. The University of California San Francisco’s Medical Center offers these suggestions:
Hard Cheese (cheddar, jack)
Salmon, canned, with bones
Tofu, soft regular
*Source: UCSF Medical Center