Calcium-Vitamin D Supplementation Increases Risk Of Urinary Tract Stones

U.S. researchers who analyzed seven years of data from more than 36,000 postmenopausal women who participated in a placebo-controlled clinical trial found that daily supplementation with calcium and vitamin D significantly increased the risk of urinary tract stones. About half of the women who participated in the Women’s Health Initiative study received 1,000 mg of calcium carbonate plus 400 of IU vitamin D3 twice daily. The rest of the women received a placebo. The researchers found that 449 women in the calcium-vitamin D group reported urinary tract stones, which was almost 18 percent more than the placebo group. “These findings have implications for [calcium-vitaminD] supplement use,” the researchers concluded. But they cautioned that the self-reported occurrence of stones was not confirmed by clinical evidence.