Answer :Bess Dawson-Hughes, MD, director of Tufts HNRCA Bone Metabolism Laboratory, answers: Current recommendations are based on the effect of vitamin D on bone health. There is some difference of opinion about the optimal level of 25-hydroxy vitamin D (the circulating form of vitamin D thats measured in blood tests) for bone. For individuals with or at risk for osteoporosis, most physicians recommend a level of at least 30 ng/ml. For the general population, some recommend 20 ng/ ml and others 30 ng/ml as the lower acceptable level. The benefit of going much above 30 ng/ ml has not been established, although ongoing research is addressing the question of whether higher levels confer added benefit.
