Older people with low blood levels of vitamin D are more likely to be depressed, say Dutch researchers.

In this new study, 1,282 men and women aged 65 to 95 had their vitamin D levels measured as part of a long-term study of aging.  Signs of depression were self-reported or discovered by standardized questionnaires.

Overall, nearly 40 percent of men and 57 percent of women had low blood levels of vitamin D. Minor depression was reported in 169 study participants while 26 were diagnosed with major depressive disorder.

Among those who suffered from depression, vitamin D levels were 14 percent lower than in people who weren't depressed.

Researchers say vitamin D could influence mood given that the vitamin plays a role in several neurological and hormonal processes. If vitamin D deficiency is a cause - rather than a result - of depression, supplementation with the vitamin and increased exposure to sunlight could help treat the mood disorder, says the study author.

Food sources of vitamin D include oily fish like salmon and tuna, eggs, fortified milk and margarine and fortified orange juice. The daily recommended intake ranges from 200 to 600 IU based on age, race, and exposure to sunlight. One 3-ounce serving of salmon provides 350 IU of vitamin D while supplements can provide up to 1000 IU. (The upper tolerable level of vitamin D is 2000 IU.) 

According to Statistics Canada, depression is more common in older adults than young adults. Chronic health problems, such as type 2 diabetes and heart disease, often accompany a depressive episode.  

Please consult your registered dietitian before starting a supplementation regime.  

This study was published in the May 2008 issue of the Archives of General Psychiatry.

All research on this web site is the property of Leslie Beck Nutrition Consulting Inc. and is protected by copyright. Keep in mind that research on these matters continues daily and is subject to change. The information presented is not intended as a substitute for medical treatment. It is intended to provide ongoing support of your healthy lifestyle practices.