Can the Sunshine Vitamin Beat the Blues?

As the summer solstice approaches, many of us notice how much long, sunny days can lift the mood. New research suggests there may be a physiological basis for this phenomenon. A recent study found that people with minor or major depression had lower vitamin D levels than people without depression.

The study, published in the Archives of General Psychiatry, was conducted in the high-latitude country of the Netherlands (where sun exposure is limited) and included people age 65 and older. Vitamin D levels in 169 people with minor depression and 26 people with major depression were compared with those from 1,087 people without depression.

Vitamin D levels were 14% lower in the people with major and minor depression compared with nondepressed people. Levels of parathyroid hormone, the hormone that helps regulate calcium levels in the body, was 5% higher in people with minor depression and 33% higher in people with major depression. When vitamin D levels are low, parathyroid hormone levels tend to rise, and high levels of this hormone have been linked to depression in the past.

D is for daylight

Vitamin D, produced through a chemical reaction that begins in sun-exposed skin cells, plays a critical role in calcium metabolism by increasing the absorption of dietary calcium and decreasing the amount of calcium lost through urine. Long known to be necessary for healthy teeth and bones, recent evidence has pointed toward its importance in preventing depression and some cancers.

Older people tend to spend less time outside than younger people, and many don’t get adequate sunshine, making them more susceptible to vitamin D insufficiency and deficiency. In the current study, almost 39% of men and 57% of women had levels of vitamin D that are considered insufficient, which means they were low but not low enough to be called deficient. The rate of depression in older people, estimated to be about 13%, is higher than in younger people.

Easy does it

“The dilemma is that sun exposure without sunscreen, which is necessary for vitamin D production, increases the risk of skin cancer,” commented Dr. Julianne Forbes, a naturopathic doctor who practices in Maine.((Same comment as on other.)) “Be sensible—cover up or use sunscreen if you plan to be in the sun for an extended period, but don’t be afraid to head out for a short walk or get short bursts of sun exposure over the course of an ordinary day.”

People can take several steps to prevent depression:

• Stay active—There is a wealth of research demonstrating a link between inactivity and depression.

• Avoid too much alcohol, which is a natural depressant.

• Eat foods rich in folic acid and vitamin B12, especially if you’re an older adult. Deficiencies in both of these vitamins are more common in seniors and are linked with depression.

• Get a little sunshine when possible, and consider supplementing with 1,000 IU of vitamin D per day, especially in the winter and if you live in a northern latitude.

(Arch Gen Psychiatry 2008;65:508–12)

Maureen Williams, ND, received her bachelor’s degree from the University of Pennsylvania and her Doctorate of Naturopathic Medicine from Bastyr University in Seattle, WA. She has a private practice in Quechee, VT, and does extensive work with traditional herbal medicine in Guatemala and Honduras. Dr. Williams is a regular contributor to Healthnotes Newswire.

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