Vitamin D won’t reduce risk of depression, new MGH study finds

A study from Massachusetts General Hospital in Boston shows that vitamin D does not reduce risk of depression in adults.Blake Nissen for the Boston Globe

Think vitamin D improves your mood? As of this week, science doesn’t support that.

According to the study from Massachusetts General Hospital released Tuesday, vitamin D, also known as the sunshine supplement, does not protect against depression in middle-age or older adults. This was one of the first studies large enough to show whether vitamin D supplementation could prevent depression in the general adult population.

The study included more than 18,000 men and women ages 50 and older. Half of the participants received vitamin D3 (cholecalciferol) supplementation for an average of five years, and the other half received a matching placebo for the same duration, according to a press release.

“There was no significant benefit from the supplement for this purpose. It did not prevent depression or improve mood” lead author Olivia I. Okereke of the MGH psychiatry department, which was recently ranked third among its specialty in the nation, said in the release.

Vitamin D is called the “sunshine vitamin” because the skin can naturally create it when exposed to sunlight. Numerous prior studies showed that low blood levels of vitamin D were associated with higher risk for depression later in life, according to the release, but there have been few large-scale trials to determine causation. With nearly 20,000 people, Okereke said the study was “statistically powered” to answer the question, and the results were clear.

Among the participants, the researchers found the risk of depression was not significantly different between those receiving vitamin D and those on the placebo, and there was no significant difference in mood scores over time.

The study, published in the medical journal JAMA, was part of a larger study that looked at cardiovascular disease and cancer prevention among nearly 26,000 people in the US. From that group, Okereke and her colleagues studied 18,353 adults who did not have any indication of clinical depression to start with.

Still, Okereke doesn’t recommend throwing away your vitamin D supplements just yet. “Not without your doctor’s advice,” she said. Some people take the vitamin for reasons other than to elevate mood.

“Vitamin D is known to be essential for bone and metabolic health, but randomized trials have cast doubt on many of the other presumed benefits,” said the paper’s senior author, JoAnn Manson, a doctor at Brigham and Women’s Hospital.

The study’s other authors include researchers from the psychiatry department at the University of Pittsburgh Medical Center and University of Pittsburgh School of Medicine, and from the VA Boston Healthcare System.