University of Pittsburgh researchers that followed 29,862 women for 11 years have found that supplementing calcium with vitamin D does not reduce hip fractures. The study, published in the Journal of Women’s Health, found that women taking calcium plus vitamin D had as many hip fractures as women taking a placebo. Women supplementing with more than 600 international units (IU) of vitamin D per day also had a 28 percent higher incidence of breast cancer.
Because hip fractures are linked to a reduction in bone density, these findings are compounded by a review of research published in The Lancet, which established that vitamin D supplements typically taken with calcium did not increase bone density among elderly adults. The review analyzed 23 studies among 4,082 participants, 92 percent of whom were women.