Calcium Supplements

Calcium is an important mineral for growth and bone health. People who do not consume enough calcium-rich foods have a higher risk of osteoporosis as they age.
Calcium Supplements - Articles
Calcium Supplements

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Calcium is an important mineral for growth and bone health. About 1.5 percent of our body weight is calcium. Most, about 99 percent, is found in our bones. People who do not eat or drink enough calcium-rich foods have a higher risk of osteoporosis as they age. Osteoporosis means "porous bones," and these bones can break easily. This can cause hip fractures, broken wrists, and painful backs (from spinal disks collapsing).

More than half of all Americans do not get enough calcium in their diets each day. The recommended allowance for 19- to 50-year-olds is 1,000 milligrams (mg). Women over 50 years old need 1,200 mg per day, while men remain at 1,000 mg. After 70, both sexes are recommended to get 1,200 mg per day. To get this amount of calcium, one would need to eat 3 to 4 servings of dairy products or other calcium-rich foods each day. For those who are lactose intolerant or don't like dairy foods, calcium supplements may be needed to get enough calcium to reduce the risk of osteoporosis.

Here's some advice on calcium supplements:

  • Calcium supplements are poorly absorbed by people who have too little stomach acid. This is more common as we age. Stomach acid is produced when you eat, so take calcium carbonate supplements with food.
  • Calcium and iron supplements compete for absorption. If taking both, do not take them at the same time of day.
  • Choose calcium supplements made of calcium carbonate or calcium citrate; avoid those containing bone meal or dolomite since they may contain mercury, arsenic, or lead, which are poisonous.
  • Remember that calcium comes from both food and supplements. Calculate how much calcium you eat from foods and use supplements to get the rest. Too much calcium can affect kidney function in the elderly and may prevent other nutrients from being absorbed.
  • Check to see if your supplement will dissolve. Drop a tablet into 6 ounces of vinegar, stirring often. After 30 minutes, a good supplement should break up and be at least 75 percent dissolved.
  • Choose supplements with added vitamin D, which is needed for calcium absorption.
  • Chew or crush calcium supplements, swallow them, and then drink at least 8 ounces of water to help further dissolve them.
  • Liquid and chewable supplements may be easiest to take in and will be absorbed more quickly. A supplement that contains more than 500 mg is not recommended. If your doctor suggests getting 1,000 mg, take the supplements twice a day
  • If calcium supplements cause side effects, try drinking more water or increasing the amount of fiber in your diet.
  • Always tell your doctor if you add calcium supplements to your diet; calcium could interfere with the effectiveness of your medications.

Tip: Choose calcium supplements made of calcium carbonate or calcium citrate; avoid supplements containing bone meal or dolomite, which may contain mercury, arsenic, or lead.

Tips Affecting Different Age Groups

  • Children should be encouraged to find calcium-rich foods that appeal to them. If dairy foods are not eaten, look for calcium-fortified soy milk, juice, cereals, or snacks. Choose foods also fortified with vitamin D, which is needed for calcium to be absorbed.
  • Adolescents need calcium the most. Don't let soda become the beverage for meals. Make calcium-rich foods part of the everyday food choices.
  • Low-fat milk, cheese, and yogurt are good choices for all ages.
  • If calcium-rich foods are not in your diet, keep bones strong with calcium supplements.
    Multivitamins do not contain enough calcium for daily needs.

Sources "Calcium and Calcium Supplements: Achieving the Right Balance."

National Institutes of Health, Office of Dietary Supplements. "Calcium." Dietary Supplement Fact Sheet. June 1, 2016.

National Institutes of Health, Osteoporosis and Related Bone Diseases National Resource Center. "Calcium and Vitamin D: Important at Every Age." May 2015.

WebMD. "Boning Up on Calcium: Supplements for Bone Health."

WebMD. "Confused About Calcium Supplements?" December 28, 2015.

Prepared and revised by Frances Alloway, extension educator and Lynn James, senior extension educator.


Nutrition research and education Diabetes education Child overweight prevention Food Safety education Food Preservation

More by Lynn James, MS, RDN, LDN 

Frances Alloway, MA, RD, LDN