Can supplements help with depression?

Can vitamin D, omega-3 fats, or other nutrients ward off depression, as many labels imply?

"Support" claims are rarely backed by good evidence.

“All kinds of supplements claim to boost your mood or prevent depression,” says Marjolein Visser, professor of nutrition and health at Vrije Universiteit in Amsterdam.

The MooDFOOD trial

Visser's MooDFOOD trial tested a supplement with five nutrients: omega-3s (1,060 milligrams of EPA + 350 mg of DHA), selenium (30 micrograms), folic acid (400 mcg), and vitamin D (20 mcg) plus calcium (100 mg).

Visser and her team randomly assigned 1,025 overweight or obese adults to take either the supplement or a placebo every day. All had depressive symptoms but had not been diagnosed with full clinical depression.

“We picked this group because if you are overweight or obese, and if you already have some symptoms, you have a higher risk of depression,” says Visser.

After one year, the results were clear.

“The number of new episodes of depression was the same in the people who took the active supplement as in the people who took the placebo pills,” says Visser. “The supplement actually did slightly worse than the placebo on depressive and anxiety symptoms.

“So there’s clear evidence that taking this combination of nutrients does not prevent depression. It’s a waste of money.”