Vitamin D deficiency has been linked to a higher risk of falls and fractures, especially among the elderly. Studies of supplementation have not given consistent results, though, so Australian scientists did a study on more than 2,000 women over 70 years old. Women got either a high dose of vitamin D or a placebo once a year. The annual dose was 500,000 IU of cholecalciferol, a technical term for vitamin D3. To the investigators’ surprise, the women treated with vitamin D had more falls and fractures in the course of the five-year study. Very few of the study participants were deficient in vitamin D at the beginning of the study. The investigators suggest that perhaps giving a year’s worth of vitamin D all at once in a single whopping dose was responsible for the unexpected harm the subjects suffered.
[Journal of the American Medical Association, May 12, 2010]
