Calcium Requirements Vary

Q:  As a postmenopausal woman, I am concerned about osteoporosis. I'd especially like to know how much calcium I should take daily. Also how much calcium is found in various foods?

Finally, is there any danger of too much calcium?

A:  All adults need a minimum of 1000 mg of calcium a day. For men and women over 50, the Institute of Medicine recommends 1200 mg a day. The National Institutes of Health recommendations on calcium intake are 1500 mg per day for women not taking estrogen. Children from age 9 to 18 need 1300 mg a day while they're building bones.

Most people get about 250 mg of calcium from a general diet, and 300 mg for each serving of dairy products. A cup of calcium-fortified orange juice also provides 300 mg. Tofu and sardines are high in calcium, comparable to dairy sources like milk, yogurt and cheese. Vegetables including broccoli, collards, kale and mustard greens also contain calcium in smaller amounts, as do dried apricots, which are yummy but expensive. Your stomach probably absorbs calcium from foods slightly better than from tablets.

Kidney stones are a possibility with high doses of 3000-5000 mg of calcium a day, but have not been seen with lower doses, except in people who have a tendency to form stones because of other problems.

For more information on this topic, see the HealthLink article Fosamax and Osteoporosis.

"Dear Doctor" is a compilation of patient questions answered by doctors from the Medical College of Wisconsin.