Traditionally, low vitamin D levels have been associated with lower bone-mineral density (BMD). However, there is no universal agreement on how to define "low". Researchers studied 230 postmenopausal women 75 years or older who had 25-hydroxyvitamin D levels between 14 and 27 ng/ml. They were free of any diseases that interfere with vitamin D or calcium absorption. Participants were randomized to either a low-dose or high-dose (800 IU daily or 50,000 IU twice monthly) cholecalciferol or a placebo. After 1 year the three groups did not differ significantly in BMD.
PositiveTip: Adequate dietary calcium and vitamin D is wise, but the value of supplementation is still uncertain.