Calcium is an essential mineral that plays a crucial role in maintaining overall health. It is well-known for its role in promoting strong bones and teeth, but it's involved in numerous other body functions and is essential for good health.
In this article, we will take a closer look at what calcium is, its key roles in the body, the best sources of calcium, and important considerations for calcium supplementation.
Calcium is a mineral that is vital for various physiological processes in the human body. It is the most abundant mineral found in the body, with approximately 99% of calcium stored in the bones and teeth. The remaining 1% is distributed throughout the blood, muscles, and cells, where it serves important physiological functions [ 1
Building and maintaining strong bones and teeth
Preventing osteoporosis, especially in older adults
Nerve signaling throughout the body
Regulating heartbeat, blood clotting, and hormone secretion
Muscle contraction and relaxation
Maintaining normal blood pressure levels and supporting the health of blood vessels
Calcium may have additional benefits, from preventing certain cancers to reducing weight, blood pressure, and bone fractures in older adults; however, research findings in these areas remain mixed and require further study [ 1
Calcium’s involvement in the body’s primary physiological processes makes it particularly important for athletic performance and recovery.
During exercise, calcium is essential for proper muscle contraction, allowing athletes to generate and sustain power, strength, and endurance. Adequate calcium intake also supports optimal nerve signaling, which is crucial for coordination, agility, muscle relaxation and recovery after exercise [ 3 4
Adequate calcium intake is also essential for bone health, as pairing this nutrient with vitamin D can further build and maintain strong, healthy bones, reduce the risk of stress fractures, and support recovery from bone injuries [ 5
While increased physical activity does not increase the need for dietary calcium intake, athletes can support their performance, reduce the risk of injuries, and promote faster recovery when they prioritize this nutrient [ 4
Calcium needs vary by age and sex. For most adults, including pregnant and breastfeeding women, the recommended dietary allowance (RDA) for calcium is 1,000 mg/day. This amount increases to 1,200 mg/day for women over the age of 50 and men over the age of 70, with the Tolerable Upper Intake Level being set at 2,500 mg/day for most adults [ 1
However, if you have a health condition or have had gastrointestinal surgery that may reduce calcium absorption, your calcium needs may be higher.
Remember that to absorb calcium and maintain strong, healthy bones effectively, your body also needs vitamin D
vitamin D. If your vitamin D level is low (like 90% of new Elo members), you may not absorb enough calcium even if you get adequate amounts in your diet.
The best dietary sources of calcium include:
Dairy products (including milk, yogurt, and cheese)
Canned sardines and salmon (with bones)
Certain vegetables, including broccoli, kale, and bok choy.
Almonds and chickpeas
Fortified foods (including some breakfast cereals, orange juice, tofu, and plant-based milk alternatives)
If you are unable to get adequate amounts of calcium from your diet, supplements can also help.
Aside from foods, calcium can also be obtained from numerous dietary supplements, including multivitamins, calcium supplements, and even milk-based protein powder
milk-based protein powder.
Calcium supplements contain varying amounts of calcium:
A whey-based protein powder
protein powdercan provide about 150 mg/scoop
Multivitamins commonly contain 200-300 mg/serving [ 1
Supplements containing only calcium or calcium with vitamin D typically provide 500-600 mg/serving [ 1
Individuals who don’t regularly consume dairy or other calcium-rich foods
People who have a health condition that limits absorption of calcium, such as Crohn’s disease or inflammatory bowel disease
Individuals who have had bariatric surgery (gastric bypass)
Talk to your doctor or dietitian to see if a calcium supplement is appropriate.
The goal of calcium supplementation is to get as close to the recommended daily intake as possible. However, if you have a health condition or have had gastrointestinal surgery that might reduce calcium absorption, your calcium needs may be higher.
Your calcium dosage should be calculated considering your overall calcium intake from all sources, including foods, beverages, and even dairy-derived protein supplements such as whey protein
If you need calcium supplements, an Elo dietitian can help you determine the appropriate dose to help you meet your daily calcium needs. Learn more about how you can get your personalized supplements started today
get your personalized supplements started today.
Knowing which calcium supplement is best can be challenging with the dizzying choices and different formulations. Here are a few things to consider when choosing the best calcium supplement for your needs.
Calcium citrate is the easiest to absorb and can be taken on an empty stomach. Calcium carbonate can be a better value but must be taken with food. [ 1
Vitamin D and magnesium enhance calcium absorption. To optimize your dose, look for calcium supplements containing one or both.
Consider the quality. The FDA does not regulate supplements. To ensure you’re getting a quality calcium supplement, choose one that has been third-party tested.
If you’re confused about the quality of calcium supplements or dosages, Elo Health takes the guesswork out of the equation by using science to recommend the proper nutrition and supplements. Not only that, but all of our supplements are also third-party tested. Learn more about our
Elo’s rigorous testing process.
The most common side effects of calcium supplements are indigestion, gas, bloating, and constipation. However, calcium carbonate appears to cause more gastrointestinal side effects than calcium citrate, especially in older adults with lower stomach acid levels [ 1
Excessive calcium supplementation can also lead to side effects (such as kidney stones) and interfere with the absorption of other minerals, like iron and zinc. To reduce the risk of these complications, keep your total calcium intake from food and supplements below 2,500 mg/day and take calcium supplements 1-2 hours before or after other supplements and medications [ 1 2
If you experience side effects, ensure you’re taking an appropriate dose. Some other ways to reduce side effects associated with calcium supplementation include switching to a different form of calcium, taking smaller doses spread out over the day, or taking it with meals [ 2
Here are some best practices and considerations for how to take calcium supplements.
Limit doses to 500 mg or less. Calcium absorption rates decrease as intakes increase. Studies show absorption from calcium supplements is highest with amounts of 500 mg or less. [ 1
Take with food for optimal absorption. Absorption will be greater when calcium supplements are taken with food, regardless of the form of calcium you take [ 1
Take other mineral supplements separately. Take calcium 1-2 hours before or after other mineral supplements, such as iron and zinc, for best absorption [ 1
Avoid high doses of calcium and vitamin D. Because vitamin D increases absorption of calcium, having high vitamin D levels (generally >80 ng/mL) can lead to dangerously high levels of calcium, particularly if you are taking calcium supplements [ 2 7
While calcium supplements can benefit individuals at risk for low calcium, calcium supplementation is not right for everyone.
Individuals with kidney disease, heart problems, heart disease, sarcoidosis, or bone tumors should avoid calcium supplements unless they are recommended by a doctor [ 2
Dolutegravir (Dovato, Tivicay)
Levothyroxine (Synthroid, Levoxyl, and others)
Lithium (Eskalith, Lithobid)
Quinolone antibiotics, including ciprofloxacin (Cipro), gemifloxacin (Factive), and moxifloxacin (Avelox).
Certain medications for diabetes, heart disease, epilepsy, and other conditions
If you take any of these medications or have a health condition, check with your doctor or dietitian about the risks of calcium before starting supplementation.
When recommended by a doctor or dietitian, calcium supplements are likely safe when taken in doses that help meet your daily calcium needs.
Calcium toxicity (hypercalcemia) can occur from very high doses of supplemental calcium, especially in combination with high vitamin D levels [ 1 2
2]. To reduce the risk of adverse side effects and complications, stick to the dosage recommended by your doctor or dietitian.
Calcium supplements may cause constipation and other gastrointestinal side effects, including gas, bloating, diarrhea, and indigestion. Calcium carbonate is more often associated with these side effects than calcium citrate, which is easier to digest and absorb [ 1
Calcium citrate is best absorbed and less dependent on stomach acid than calcium carbonate. It can be taken with or without food, though absorption will be higher if taken with food [ 1
Calcium is a vital mineral that plays a crucial role in maintaining overall health. It is primarily known for promoting strong bones and teeth, but adequate calcium intake also supports muscle function, the nervous system, cardiovascular health, and dental health, as well as athletic performance and recovery. Dairy products, leafy green vegetables, fortified foods, fish, and legumes are excellent dietary sources of calcium. Individuals at risk for low calcium may benefit from calcium supplementation. At Elo
Elo, our expert dietitians can help you determine whether calcium supplements might benefit you.
Disclaimer: The text, images, videos, and other media on this page are provided for informational purposes only and are not intended to treat, diagnose, or replace personalized medical care.
Most adults, including pregnant and breastfeeding women, need 1,000 mg of calcium daily. However, due to changes in calcium absorption and bone turnover with age, women over 50 and men over 70 need 1,200 mg/day [ 1
Increased physical activity does not increase the need for dietary calcium intake; however, athletes can support their performance, reduce the risk of injuries, and promote faster recovery by prioritizing calcium intake [ 4
If your vitamin D level is low, you may not absorb enough calcium even if you get adequate amounts in your diet.
For best absorption, calcium supplements should be taken with food in doses below 500 mg and contain vitamin D and/or magnesium.
Elo Health dietitians can help you determine whether calcium supplementation is beneficial and recommend the best type and dosage for you.
Office of Dietary Supplements - Calcium. (n.d.). https://ods.od.nih.gov/factsheets/Calcium-HealthProfessional/
Griffin, R. M. (n.d.). Health Benefits of Calcium. WebMD. https://www.webmd.com/diet/supplement-guide-calcium#091e9c5e801b56bf-2-6
Thomas, D. T., Erdman, K. A., & Burke, L. M. (2016). Position of the Academy of Nutrition and Dietetics, Dietitians of Canada, and the American College of Sports Medicine: Nutrition and Athletic Performance. Journal of the Academy of Nutrition and Dietetics, 116(3), 501–528. https://doi.org/10.1016/j.jand.2015.12.006
Kunstel, K. (2005). Calcium Requirements for the Athlete. Current Sports Medicine Reports, 4(4), 203–206. https://doi.org/10.1097/01.csmr.0000306208.56939.01
Fischer, V., Haffner-Luntzer, M., Amling, M., & Ignatius, A. (2018). Calcium and vitamin D in bone fracture healing and post-traumatic bone turnover. European cells & materials, 35, 365–385. https://doi.org/10.22203/eCM.v035a25
UpToDate. (n.d.). UpToDate. https://www.uptodate.com/contents/calcium-and-vitamin-d-for-bone-health-beyond-the-basics
Tebben, P. J., Singh, R. J., & Kumar, R. (2016). Vitamin D-Mediated Hypercalcemia: Mechanisms, Diagnosis, and Treatment. Endocrine reviews, 37(5), 521–547. https://doi.org/10.1210/er.2016-1070