High Doses of Vitamin D Don’t Strengthen Bones
High doses of vitamin D do not increase bone density, and they may even lower it, researchers report. In a double-blinded, three-year clinical trial published in JAMA, scientists randomized 311 healthy adults without osteoporosis to daily doses of 400, 4,000 or 10,000 units of vitamin D. At the beginning and end of the study, they…