Task Force Recommends Against Vitamin D, Calcium Supplements

A federal government task force report advised against taking daily vitamin D and calcium supplements to prevent fractures.

Despite widespread belief that taking daily vitamin D and calcium supplements will protect postmenopausal women against osteoporosis-related fractures, a draft report released on June 12, 2012, by the United States Preventive Services Task Force recommends against the practice.

The report finds that the supplements may not reduce the risk of fractures, and may instead lead to an increased risk of kidney stones. As a result, the report authors recommend against daily supplementation with more than 400 IU of vitamin D and more than 1000 mg of calcium in postmenopausal women. The report also found that the supplements have an inconclusive benefit in men of any age and in premenopausal women. The proposed changes are open to public comment until July 10.

The report draws on an evidence review published on December 20, 2011, that analyzed the effects of daily vitamin D and calcium in postmenopausal and premenopausal women and men. The review looked at 16 randomized, controlled trials in which participants received either a placebo or vitamin D and calcium supplements. Although the report and many trials focused on postmenopausal women, the report authors noted that several studies included both male and female participants.

Participants in most of the trials received at least 800 IU of vitamin D, although the dose varied for each trial. Several trials also included a 1000 mg dose of calcium in addition to vitamin D. In the largest trial, conducted by the Women’s Health Initiative (WHI), however, participants in the intervention group took 400 IU of vitamin D and 1000 mg of calcium.

Trials of vitamin D supplementation only as well as those including vitamin D and calcium supplementation showed no statistically significant reduction in fractures. In addition, the WHI trial reported no reduction in hip or other fractures from the combination therapy.

A number of studies included in the review did not track adverse reactions, but the WHI trial found an increased risk for renal and urinary tract stones among participants who took supplements. Several other studies reported cases of musculoskeletal soreness, hypercalcemia, primary hyperparathyroidism, and gastrointestinal symptoms, including constipation, diarrhea, and upset stomach. However, those studies noted that the adverse events may not be associated with the supplements.