Calcium and calcium supplements: Achieving the right balance
Calcium is important for bone health. See how much you need and how to get it.By Mayo Clinic Staff
Calcium is important for bone health throughout your life. Although diet is the best way to get calcium, calcium supplements may be an option if your diet falls short.
Before you consider calcium supplements, be sure you understand how much calcium you need, the pros and cons of calcium supplements, and which type of supplement to choose.
The benefits of calcium
Your body needs calcium to build and maintain strong bones. Your heart, muscles and nerves also need calcium to function properly.
Some studies suggest that calcium, along with vitamin D, may have benefits beyond bone health: perhaps protecting against cancer, diabetes and high blood pressure. But evidence about such health benefits is not definitive.
The risks of too little calcium
If you don't get enough calcium, you could face health problems related to weak bones:
- Children may not reach their full potential adult height.
- Adults may have low bone mass, which is a risk factor for osteoporosis.
Many Americans don't get enough calcium in their diets. Children and adolescents are at risk, but so are adults age 50 and older.
How much calcium you need depends on your age and sex.
Calcium: Recommended daily amount
|71 and older
|51 and older
The recommended upper limit for calcium is 2,500 mg a day for adults 19 to 50. For those 51 and older, the limit is 2,000 mg a day.
Calcium and diet
Your body doesn't produce calcium, so you must get it through other sources. Calcium can be found in a variety of foods, including:
- Dairy products, such as cheese, milk and yogurt
- Dark green leafy vegetables, such as broccoli and kale
- Fish with edible soft bones, such as sardines and canned salmon
- Calcium-fortified foods and beverages, such as soy products, cereal and fruit juices, and milk substitutes
To absorb calcium, your body also needs vitamin D. A few foods naturally contain small amounts of vitamin D, such as canned salmon with bones and egg yolks. You can also get vitamin D from fortified foods and sun exposure. The RDA for vitamin D is 600 international units (15 micrograms) a day for most adults.
Who should consider calcium supplements?
Even if you eat a healthy, balanced diet, you may find it difficult to get enough calcium if you:
- Follow a vegan diet
- Have lactose intolerance and limit dairy products
- Consume large amounts of protein or sodium, which can cause your body to excrete more calcium
- Are receiving long-term treatment with corticosteroids
- Have certain bowel or digestive diseases that decrease your ability to absorb calcium, such as inflammatory bowel disease or celiac disease
In these situations, calcium supplements may help you meet your calcium requirements. Talk with your doctor or dietitian about whether calcium supplements are right for you.
Do calcium supplements have risks?
Calcium supplements aren't for everyone. For instance, if you have a health condition that causes excess calcium in your bloodstream (hypercalcemia), you should avoid calcium supplements.
It's not definitive, but there may be a link between high-dose calcium supplements and heart disease. The evidence is mixed and more research is needed before doctors know the effect calcium supplements may have on heart attack risk.
A similar controversy surrounds calcium and prostate cancer. Some studies have shown that high calcium intake from dairy products and supplements may increase risk, whereas another more recent study showed no increased risk of prostate cancer associated with total calcium, dietary calcium or supplemental calcium intakes.
Until more is known about these possible risks, it's important to be careful to avoid excessive amounts of calcium. As with any health issue, it's important to talk to your doctor to determine what's right for you.
Types of calcium supplements
Several different kinds of calcium compounds are used in calcium supplements. Each compound contains varying amounts of calcium — referred to as elemental calcium. Common calcium supplements may be labeled as:
- Calcium carbonate (40% elemental calcium)
- Calcium citrate (21% elemental calcium)
- Calcium gluconate (9% elemental calcium)
- Calcium lactate (13% elemental calcium)
The two main forms of calcium supplements are carbonate and citrate. Calcium carbonate is cheapest and therefore often a good first choice. Other forms of calcium in supplements include gluconate and lactate.
In addition, some calcium supplements are combined with vitamins and other minerals. For instance, some calcium supplements may also contain vitamin D or magnesium. Check the ingredient list to see which form of calcium your calcium supplement is and what other nutrients it may contain. This information is important if you have any health or dietary concerns.
Choosing calcium supplements
When looking at calcium supplements, consider these factors:
Amount of calcium
Elemental calcium is important because it's the actual amount of calcium in the supplement. It's what your body absorbs for bone growth and other health benefits. The Supplement Facts label on calcium supplements is helpful in determining how much calcium is in one serving. As an example, calcium carbonate is 40% elemental calcium, so 1,250 milligrams (mg) of calcium carbonate contains 500 mg of elemental calcium. Be sure to note the serving size (number of tablets) when determining how much calcium is in one serving.
Calcium supplements cause few, if any, side effects. But side effects can sometimes occur, including gas, constipation and bloating. In general, calcium carbonate is the most constipating. You may need to try a few different brands or types of calcium supplements to find one that you tolerate the best.
What prescriptions you take
Calcium supplements can interact with many different prescription medications, including blood pressure medications, synthetic thyroid hormones, bisphosphonates, antibiotics and calcium channel blockers. Depending on your medications, you may need to take the supplement with your meals or between meals. Ask your doctor or pharmacist about possible interactions and which type of calcium supplement would work for you.
Quality and cost
Manufacturers are responsible for ensuring that supplements are safe and claims are truthful. Some companies have their products independently tested by U.S. Pharmacopeial Convention (USP), ConsumerLab.com (CL) or NSF International. Supplements that bear the USP, CL or NSF abbreviation meet voluntary industry standards for quality, purity, potency, and tablet disintegration or dissolution. Different types of calcium supplements have different costs. Comparison shop if cost is a factor for you.
Calcium supplements are available in a variety of forms, including tablets, capsules, chews, liquids and powders. If you have trouble swallowing pills, you may want a chewable or liquid calcium supplement.
Your body must be able to absorb the calcium for it to be effective. All varieties of calcium supplements are better absorbed when taken in small doses (500 mg or less) at mealtimes. Calcium citrate is absorbed equally well when taken with or without food and is a form recommended for individuals with low stomach acid (more common in people over 50 or taking acid blockers), inflammatory bowel disease or absorption disorders.
More isn't always better: Too much calcium has risks
Dietary calcium is generally safe, but more isn't necessarily better, and excessive calcium doesn't provide extra bone protection.
If you take calcium supplements and eat calcium-fortified foods, you may be getting more calcium than you realize. Check food and supplement labels to monitor how much total calcium you're getting a day and whether you're achieving the RDA but not exceeding the recommended upper limit. Be sure to tell your doctor if you're taking calcium supplements.
Nov. 01, 2022
From Mayo Clinic to your inbox
Sign up for free, and stay up to date on research advancements, health tips and current health topics, like COVID-19, plus expertise on managing health. Click here for an email preview.
ErrorEmail field is required
ErrorInclude a valid email address
To provide you with the most relevant and helpful information, and understand which
information is beneficial, we may combine your email and website usage information with
other information we have about you. If you are a Mayo Clinic patient, this could
include protected health information. If we combine this information with your protected
health information, we will treat all of that information as protected health
information and will only use or disclose that information as set forth in our notice of
privacy practices. You may opt-out of email communications at any time by clicking on
the unsubscribe link in the e-mail.
Thank you for subscribing!
You'll soon start receiving the latest Mayo Clinic health information you requested in your inbox.
Sorry something went wrong with your subscription
Please, try again in a couple of minutes
See more In-depth
- Calcium and vitamin D: Important at every age. National Institutes of Health. https://www.bones.nih.gov/health-info/bone/bone-health/nutrition/calcium-and-vitamin-d-important-every-age. Accessed Oct. 18, 2020.
- Calcium. Natural Medicines. http://naturalmedicines.therapeuticresearch.com. Accessed Oct. 18, 2020.
- Calcium fact sheet for professionals. Office of Dietary Supplements. https://ods.od.nih.gov/factsheets/Calcium-HealthProfessional/. Accessed Oct. 18, 2020.
- Rosen HN. Calcium and vitamin D supplementation in osteoporosis. https://www.uptodate.com/contents/search. Accessed Oct. 18, 2020.
- 2015-2020 Dietary Guidelines for Americans. U.S. Department of Health and Human Services and U.S. Department of Agriculture. https://health.gov/our-work/food-nutrition/2015-2020-dietary-guidelines/guidelines/introduction/dietary-guidelines-for-americans/. Accessed Oct. 18, 2020.
- Dietary Guidelines Advisory Committee. Scientific report of the 2020 Dietary Guidelines Advisory Committee: Advisory report to the Secretary of Agriculture and the Secretary of Health and Human Services. U.S. Department of Agriculture, Agricultural Research Service. https://www.dietaryguidelines.gov/2020-advisory-committee-report. Accessed Oct. 18, 2020.
- What people with celiac disease need to know about osteoporosis. NIH Osteoporosis and Related Bone Diseases National Resource Center. https://www.bones.nih.gov/health-info/bone/osteoporosis/conditions-behaviors/celiac. Accessed Oct. 18, 2020.
- Dietary supplements verification program. U.S. Pharmacopeial Convention. https://www.usp.org/verification-services/dietary-supplements-verification-program. Accessed Oct. 18, 2020.
- About ConsumerLab.com. ConsumerLab.com. https://www.consumerlab.com/aboutcl.asp. Accessed Oct. 18, 2020.
- What is third-party certification? NSF International. https://www.nsf.org/about-nsf/what-is-third-party-certification. Accessed Oct. 18, 2020.