An influential U.S. group of medical experts has concluded there isn't enough evidence to justify postmenopausal women taking supplements of calcium and vitamin D for maintaining their bone health. Daily supplements of 1,000 milligrams of calcium and 400 IU of vitamin D provide only a small amount of protection against fractures, according to U.S. Preventive Services Task Force, whose members are appointed by the U.S. Department of Health and Human Services.
And, on the downside, calcium pills slightly increase the risk of kidney stones.
"The current evidence is insufficient to assess the balance of benefits and harms of daily supplementation," the group concluded in draft recommendations posted on its website. (It did not address the issue of higher-dose supplements.)
The findings represent the latest in a series of reports that have challenged the need for routine supplementation. Several recent studies have suggested calcium supplements may actually increase the risk of cardiovascular disease, including heart attacks and strokes.
As a general rule, dietitians say you should meet your calcium needs through the food you eat, rather than pills. But vitamin D supplements are still essential for most people at least for part of the year. Vitamin D is produced naturally in the body when skin is exposed to sunlight. During winter months, the sun's rays are too weak is to generate vitamin D.