Calcium is a very important mineral that is stored in large amounts in the body’s bones and teeth. It performs many functions in the body and consuming it regularly is essential to good health, but what are the benefits of calcium, where can you find it, and how much is too much?
Where is calcium found?
There are fortunately many calcium-rich foods available. Some plant-based sources include broccoli, kale, Chinese cabbage, and many other vegetables. It is also found in high amounts in dairy products such as milk, cheese, and yogurt. Many foods are also fortified with calcium, including some fruit drinks, cereal, and tofu.
Calcium is also found in dietary supplement form, usually as calcium carbonate or calcium citrate. Both are effective; however, the body absorbs calcium carbonate best with food whereas calcium citrate can be taken at any time. In addition, calcium carbonate contains a higher percentage of elemental calcium than calcium citrate; however, this is listed on the label so you can ensure you are meeting your needs. Some multivitamin supplements contain calcium, and dietary supplements containing only calcium carbonate or citrate are available.
Why is calcium important?
The vast majority of the body’s calcium is found in the bones and teeth to support their strength and structure. Bones also regulate the blood levels of calcium so they stay within a certain healthy range and calcium can perform many other functions.
Calcium helps in contraction and dilation of the blood vessels, and it helps muscles contract and do work. Calcium is also essential for communication between neurons and parts of cells, and it helps secrete hormones.
What is the RDA for calcium?
The Recommended Dietary Allowance (RDA) for calcium is 1,000 mg for men and women between 19 and 50 years of age. The RDA for ages 51 to 70 is 1,000 mg of calcium for men and 1,200 mg of calcium for women. The RDA for men and women over 70 years of age is 1,200 mg of calcium.
The RDA for calcium for adolescents between nine and 18 years of age is 1,300 mg to support growing bones. The RDA is 1,00 mg for children between four and eight years of age, 700 mg for toddlers between one and three years of age, 260 mg for infants between seven and twelve months, and 200 mg for infants under seven months of age. Calcium can be transmitted through breast milk, and infant formulas are usually fortified with calcium.
These values are given by the National Institutes of Health, and the RDA represents the daily intake sufficient to meet the dietary needs of 97 to 98 percent of healthy individuals. Fortunately, it is pretty easy to meet the RDA for calcium with food or supplements. Eight ounces of low-fat yogurt contains 32 percent of the RDA, and one cup of calcium-fortified orange juice contains 27 percent of the RDA.
How much is too much?
The tolerable Upper Intake Level (UL) for calcium is 2,500 mg for adults between 19 and 50 years of age and 2,000 mg for adults above 50 years of age. The UL is 3,000 mg for adolescents between nine and 18 years of age, 2,500 mg for children between one and eight years of age, 1,500 mg for infants between seven and twelve months, and 1,000 mg for infants under seven months of age. These values are given by the National Institutes of Health, and the UL represents the maximum daily intake that is unlikely to cause adverse health effects.
Too much calcium in the blood is called hypercalcemia, and it is usually caused by taking too much supplemental calcium. Hypercalcemia can cause kidney issues, calcification of the soft tissues and blood vessels, and constipation. It has also been shown in some studies to potentially be associated with an increased risk of cardiovascular disease, however more research is needed to confirm this.
Supplemental calcium can interact with various medications, including but not exclusive to certain diuretics, some antibiotics, levothyroxine, and phenytoin, so it is important to tell your doctor about any supplements you are taking.
What are the benefits of calcium?
There are also benefits to getting an adequate intake of calcium in the diet. Firstly, according to the Food and Drug administration, adequate calcium and vitamin D intake with physical activity could potentially help lower the risk of osteoporosis in late adulthood. Osteoporosis is a very common health condition that disproportionately affects older women, and it can increase the risk of bone fractures due to fragile bone structure. Bone mass peaks at about age 30, and it is important to focus on building strong bones throughout childhood and adolescence by eating a healthy diet and getting physical activity.
In addition, calcium supplementation could potentially help reduce the risk of preeclampsia, a condition during pregnancy that causes high blood pressure and proteinuria. The World Health Organization recommends that women with low calcium levels consider taking between 1,500 and 2,000 mg of calcium between 20 weeks’ gestation until delivery.
Low intakes of calcium could potentially result in adverse health consequences down the road. Some groups are more at risk of this than others. For example, postmenopausal women often have greater calcium needs because of lower estrogen production.
Another condition where low estrogen production could potentially contribute to greater calcium requirements is amenorrhea, or temporary cessation of a menstrual cycle in premenopausal women. This condition can sometimes result from stress or very low body fat, which can stem from over exercising or undereating. Since their calcium needs are greater, they are less likely to consume sufficient calcium to meet their needs.
People who avoid dairy products, such as vegans or people who are lactose intolerant, may also be at an increased risk of calcium deficiency since dairy products are a good source of calcium. People following these dietary choices would benefit from should consuming other foods that are rich in calcium, and watch their calcium levels.
Low calcium intakes typically do not result in immediate symptoms, however adverse effects may be observed later in life. The risk of osteoporosis increases with low calcium intakes, and this can result in a greater risk of bone fractures.
The consequences of consistently low calcium intakes can potentially be reduced and prevented by consuming enough calcium, either through dietary sources or supplementation.
If you think you have a calcium deficiency or are at an increased risk, consider getting your blood levels tested. As always, consult your doctor before you begin taking any vitamin or mineral supplement, to make sure your medications or health conditions don’t make it a serious risk.
Bolland, M. J., Grey, A., Avenell, A., Gamble, G. D., & Reid, I. R. (2011). Calcium supplements with or without vitamin D and risk of cardiovascular events: Reanalysis of the Women’s Health Initiative limited access dataset and meta-analysis. BMJ, 342(Apr19 1), D2040-D2040. doi:10.1136/bmj.d2040
Electronic Code of Federal Regulations. (2006, August 17). Retrieved September 13, 2020, from https://www.ecfr.gov/cgi-bin/text-idx?SID=c7e427855f12554dbc292b4c8a7545a0
Office of Dietary Supplements – Calcium. (2020, March 26). Retrieved September 13, 2020, from https://ods.od.nih.gov/factsheets/Calcium-HealthProfessional/
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