## A universal vitamin? Vitamin D is sometimes called the "sunshine vitamin" because the body naturally creates it when a person is exposed to the sun. Low blood levels of vitamin D (25-hydroxy vitamin D) were thought to be associated with a high risk of depression in people over 50. But a number of scientists have questioned this and have conducted several large-scale randomized studies to determine the cause-and-effect relationship. The largest was led by Olivia I. Okereke, MD, of Massachusetts General Hospital. ## Evidence base More than 18,000 men and women aged 50 and older participated in the study. Half of the participants received vitamin D3 (cholecalciferol) for an average of five years, and the other half received a placebo for the same period of time. The results stunned even the authors of the study. By observing the condition of the participants, the researchers found that the risk of depression or clinically significant depressive symptoms did not differ significantly between those who received active vitamin D3 supplements and those who took the placebo. The subjects did not even show significant differences in mood scores. "Vitamin D is known to be essential for bone health, but randomized trials have called into question many of the other purported benefits," Okereke says, "so I would reconsider the tendency to prescribe it for any other purpose. __Sources__: JAMA (2020). DOI : 10.1001/jama.2020.10224 Journal of the American Medical Association