The USPSTF concludes that the current evidence is insufficient to assess the balance of the benefits and harms of vitamin D and calcium supplementation, alone or combined, for the primary prevention of fractures in men and premenopausal women.
- Whether daily supplementation with greater than 400 IU of vitamin D3 and greater than 1,000 mg of calcium reduces fracture incidence in postmenopausal women or older men.
- Prospective studies to assess the potential benefits of vitamin D and calcium supplementation in premenopausal women on fracture incidence later in life.
- Effects of vitamin D supplementation on diverse populations, as results from studies of white women cannot be extrapolated to nonwhite populations.
- Studies to evaluate the potential harms of supplementation, particularly studies on calcium and potential adverse cardiovascular outcomes.