In a study that gives new meaning to the phrase
sunny disposition, Oregon State University researchers have found people who suffer with depression tend to have low levels of vitamin D — the so-called “sunshine vitamin” because it is produced by the body in response to sunlight.
The study, the journal Psychiatry Research, found that young women with lower levels of vitamin D were more likely to have clinically significant depressive symptoms.
Lead researcher David Kerr, an associate professor in the School of Psychological Science at OSU, said the results held true even when researchers took into account other possible explanations, such as time of year, exercise, and time spent outside.
"Depression has multiple, powerful causes and if vitamin D is part of the picture, it is just a small part," said Kerr, who published his findings in the journal Psychiatry Research. "But given how many people are affected by depression, any little inroad we can find could have an important impact on public health."
Vitamin D is an essential nutrient for bone health and muscle function. People create their own vitamin D when their skin is exposed to sunlight. Vitamin D also is found in some foods, including milk that is fortified with it, and is available in supplements.
The recommended daily allowance of vitamin D is 600 IU per day, but there is no established level of vitamin D sufficiency for mental health.
Past studies have linked low vitamin D levels to impaired immune function, some forms of cancer and cardiovascular disease.
"Vitamin D supplements are inexpensive and readily available." Kerr said. "They certainly shouldn't be considered as alternatives to the treatments known to be effective for depression, but they are good for overall health."
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