The 6 Best Calcium Supplements of 2023

Is a Calcium Supplement Beneficial?

The bottom line is that not everyone needs a calcium supplement, but some people may benefit from taking one. A calcium supplement does not make up for other factors that contribute to strong bones and overall health. It is important to eat an adequate and nutritious diet (being underweight is a risk factor for poor bone health and increased mortality) and exercise regularly. Smoking and excessive alcohol consumption can also contribute to weaker bones and other health issues.

Calcium is an important mineral for all people to consume, but some groups require more of it or are more at risk for calcium deficiency. 

People with malabsorption conditions, such as inflammatory bowel disease and other diseases or previous surgeries affecting the intestines

People who use steroids may need a calcium supplement, as steroids can affect how your body uses calcium and vitamin D and can lead to bone loss.

Adolescent girls may benefit from a calcium supplement. Bone growth starts before birth and continues until age 20 to 25 years old, so early intake of calcium is important. For girls, increasing intake of calcium-containing foods and potentially adding a calcium supplement may help build bones and prevent or delay osteoporosis later in life.

Postmenopausal women may or may not benefit from a calcium supplement. After age 25 to 30, bones tend to get weaker. Postmenopausal women specifically have a higher risk of bone fractures because of changing hormone levels which causes bones to “shed” calcium. Increased dietary calcium may be beneficial during this time, and a supplement may or may not be helpful.

Those with diets low in calcium, such as many folks following vegan diets, will benefit from taking a calcium supplements or consistently consuming calcium-fortified foods.

Who May Not Benefit from Calcium

Those who get enough calcium from food: Again, a supplement would be to complement dietary calcium intake, so it’s important that your total intake does not go over the upper limit, which ranges from 2,000 to 3,000 milligrams per day, depending on your age. Over supplementation of calcium may cause constipation, lead to kidney stones or kidney damage, and even contribute to cardiac and respiratory failure.

Those with kidney stones: If you have a history of kidney stones or heart disease, you should consult with your doctor before beginning a calcium supplement.

Those taking levothyroxine: Calcium supplements can also interfere with the absorption of thyroid hormones, so those taking levothyroxine (Synthroid) there would need to leave a time gap between taking these two pills.

Those taking antacids: If you frequently take antacids, such as Tums, exercise caution when supplementing with calcium as well.

How We Select Supplements

Our team works hard to be transparent about why we recommend certain supplements; you can read more about our dietary supplement methodology to get familiar with the process. 

We support supplements that are evidence-based and rooted in science. We value certain product attributes that we find to be associated with the highest quality products. We prioritize products that are third-party tested and certified by one of three independent, third party certifiers: USP, NSF, or ConsumerLab. We also consulted Anya Rosen, MS, RD, LD, CPT, and founder of New York City virtual clinic Birchwell, for her expert opinion on what to look for when choosing calcium supplements.

It's important to note that the FDA does not review dietary supplements for safety and effectiveness before they go to market. Our team of experts has created a detailed, science-backed methodology to choose the supplements we recommend.

The Confusing Research on Calcium Supplements

Although we know that calcium plays a vital role in the body and that consuming enough calcium from foods is very important, the research on calcium supplements is less clear. Many supplement companies still make claims about how their product might benefit you, and these promises are not necessarily backed by quality research. Let’s look into a few areas where calcium supplementation may or may not be beneficial. 

Osteoporosis

Osteoporosis is a skeletal disorder that causes weaker bones and is usually associated with aging. People with osteoporosis have a higher risk of fracture. Women are at greater risk of this than men because they naturally have smaller bones and, after menopause, estrogen (which helps protect bones) decreases significantly. In theory, supplementing with calcium and vitamin D could reduce this risk, but research does not necessarily support this.

Some research has shown that higher dietary calcium intake is linked to greater bone mineral density in women over 60; other research has shown no effect. The evidence on calcium supplementation and fractures is also inconclusive. A meta analysis (research that looks at many different studies) showed no effect of calcium and vitamin D supplementation on hip fracture risk.

Cancer Prevention

Calcium has also been studied to see if it may help prevent cancer. Most high quality research has shown no effect from calcium and vitamin D supplementation on cancer risk, though one study showed that higher total calcium intake may decrease the risk of colorectal cancer.

Cardiovascular Diseases

In the blood, calcium helps to decrease the amount of fat your body absorbs, and therefore people have wondered if it may reduce the risk of cardiovascular disease (CVD). It looks like this might be the case for eating more calcium in the diet but not with calcium supplements.

A large study in Australia found that adults with the highest calcium intake from their diets, excluding supplements, had a 25% lower risk of stroke. On the other hand, there is evidence that calcium supplements may increase CVD. In one large-scale study of women, calcium supplements (with or without vitamin D) were associated with a modestly higher risk of cardiovascular events, especially heart attacks.

Preeclampsia

The leading cause of illness and death related to pregnancy and childbirth for both mother and baby in the United States is preeclampsia. This condition is a combination of high blood pressure and protein in the urine that occurs sometime after 20 weeks of pregnancy.

According to the American College of Obstetrics and Gynecology, supplementing daily with 1,500–2,000 mg calcium might reduce the severity of preeclampsia in pregnant people, but only for those who consume less than 600 mg/day of calcium.

Weight Loss

The research on calcium supplements and weight loss is also mixed. So we turn to the highest quality research to draw conclusions from, a research analysis, which looks at the results of many studies. In a research analysis that looked at 41 studies, no association was found between increased dairy food intake or supplemental calcium intake on weight loss.

What to Look for in a Calcium Supplement

Third-Party Testing

Supplements that are third-party tested are sent to a lab where they are tested to ensure they contain what they say they contain and are not contaminated with specific high-risk, common contaminants. However, it’s important to note:

1. Third party testing does not test to see if a product is effective or safe for everyone, and it does not ensure the supplement will not interact with other supplements or medications.
2. Not all third-party testing is created equal. It is not uncommon for supplement companies to pay labs for certificates after conducting minimal to no testing. 
3. The third party certifications we can trust are: ConsumerLab, NSF, and USP. However, these certifications are difficult to obtain and/or expensive for manufacturers, so many companies choose not to get their products tested by one of these three organizations. 
4. Sometimes products tested by these three companies are more expensive to try to offset the cost they pay for certification.
5. Just because a supplement is not tested by one of these three companies, it does not mean it’s a bad product. We recommend doing some research on the reputability of the manufacturer, and calling up the manufacturer and their testing lab to determine their protocols and decide if you feel comfortable consuming the supplement.

When choosing a supplement, it’s important to obtain it from a trusted source that upholds standards of efficacy and purity, and calcium is no exception. One of the biggest concerns with calcium supplements is related to the quantity of the mineral actually contained in the pill or powder. A product label may say it contains a certain amount of calcium, but in fact it falls short. Another concern is that many sources of calcium also contain heavy metals such as lead, arsenic, and cadmium. Choosing your supplement from a trusted source is imperative, especially for women who are pregnant.

Form

There are many types of calcium available in various forms. Some are more effective and desirable than others. The most commonly available forms are: calcium carbonate, calcium malate, calcium citrate, tricalcium phosphate, calcium lactate, and calcium gluconate. Let's look in more depth at the four of these forms used in our top supplement picks.

Calcium carbonate is the most common and also the least expensive form. However, it can cause gastrointestinal upset, such as bloating, gas, and constipation.

Calcium malate and calcium citrate are the forms that are more effective at raising calcium levels compared to carbonate, but it’s important to consume these two forms with a meal as they do require stomach acid (which our bodies produce when we eat) to be best absorbed.

Tricalcium phosphate is not only used as a supplement but also as an additive to powdered food items to prevent caking and in processed foods to enrich or fortify them with calcium. Possible side effects include nausea, vomiting, constipation, increased thirst, increased urination, and decreased appetite. It can also interact with certain medications and may not be ideal for people with certain health conditions.

As a final consideration, all of these forms of calcium, with the exception of carbonate, usually come in the form of large pills or multiple tablets and can be more expensive.

Ingredients & Potential Interactions

It is essential to carefully read the ingredient list and nutrition facts panel of a supplement to know which ingredients and how much of each ingredient is included, relative to the recommended daily value of that ingredient. Please bring the supplement label to a healthcare provider to review the different ingredients contained in the supplement and any potential interactions between these ingredients and other supplements and medications you are taking.

Calcium relies on vitamin D for absorption, and so it’s not uncommon to see calcium supplements containing vitamin D as well. Vitamin K and magnesium, which also helps promote calcium deposition in bone, might also be found in the same supplement. 

Magnesium plays an important role in the absorption and metabolism of both vitamin D and calcium. Specifically, magnesium is required to convert vitamin D into its active form, which is essential for optimizing absorption and utilization of calcium. Additionally, magnesium helps to maintain calcium homeostasis in the body by stimulating a hormone called calcitonin, which draws calcium out of the blood and soft tissue and into the bones.

Due to the synergistic relationship of these nutrients, making sure you have adequate amounts of all three (calcium, magnesium, and vitamin D) is important for optimal health. However, if you are meeting your RDA for magnesium through your diet, you do not necessarily need additional magnesium supplementation. The RDA for magnesium for adults aged 18+ ranges from 310 milligrams/day to 420 milligrams/day depending on age, gender and pregnancy status.

Remember, the idea is to meet the RDA for all nutrients with a food first approach, and supplement as needed. Excess of any one nutrient through supplementation can disrupt your body's inherent ability to maintain optimal homeostasis of vitamins and minerals in the body.

Calcium Dosage

According to current recommendations from the Dietary Guidelines for Americans, the Recommended Dietary Allowances (RDAs) for calcium are as follows:

• Birth to 1 year: 200 mg for men and women
• 7-12 months: 260 mg for men and women
• 1-3 years: 700 mg for men and women
• 4-8 years: 1,000 mg for men and women
• 9-18 years: 1,300 mg for men and women
• 19-50 years: 1,000 mg for men and women
• 51-70 years: 1,000 mg for men, 1,200 mg for women
• Over 70 years: 1,200 mg for men and women
• Pregnant women under 19 years: 1,300 mg
• Pregnant women 19 and over: 1,000 mg
• Lactating women under 19 years: 1,300 mg
• Lactating women 19 and over: 1,000 mg

How Much is Too Much?

Excessive calcium supplementation can cause dangerous health problems; therefore, Tolerable Upper Intake Levels (ULs) have been established. No matter whether you get your calcium from food or supplements, you should not exceed:

2500 mg per day for those aged 1-8 years and 19-50 years old

3000 mg per day for those aged 9-18 years

2000 mg per day for those aged 51 and older

It is important not to exceed these limits because, although rare, hypercalcemia (high serum calcium) or hypercalciuria (high urine calcium) can lead to poor muscle tone, kidney issues, constipation, nausea, weight loss, fatigue, heart arrhythmias, and a higher risk of death from heart disease.