Researchers from Southwestern Medical Center have found that a lack of vitamin D is associated with the development of depression.
Depression currently affects one in 10 American people at some point in their lives, a problem that should not be underestimated as suicide is the tenth leading cause of death and amounted to 11.3 deaths per 100,000.
In 2007, 34,598 people lost their lives to suicide. For every death, National Institute of Mental Health estimates there are another 11 suicide attempts.
After screening 12,600 people for vitamin deficiency between 2006-2010, the researchers found that those with higher levels of vitamin D had less risk of depression, even in those people who had a previous history of depression. They also found that low vitamin D levels were associated with symptoms of depression.
They aren’t sure whether it is the depression that is causing the low vitamin D levels or whether the low vitamin D levels cause the depression, but said that a lack of the vitamin can lead to inflammation and that in turn can affect the neurotransmitters of the brain.
How Does Inflammation Cause Depression?
The National Institute for Mental Health says that when a person is infected with a virus or bacteria, it stimulates their immune system to produce cytokines. The cytokines trigger the immune system to defend the person and help them fight the infection.
However, cytokines also trigger inflammation and this inflammation can cause changes in behavior, withdrawal and fatigue. Cytokines are known to cause depression in people with physical illnesses even when they have no history of mental illness.
In animal tests, scientists used a BCG vaccine to induce chronic inflammation. They infected mice with high doses of BCG to persistently activate the immune system. Once the mice recovered from their illness, they developed depressive-like behavior.
The same effect is seen in humans when they receive cytokine interferon a for the treatment of cancer. One-third of these patients go on to develop major depression. Vitamin D has been demonstrated to be anti-inflammatory, so this may be why people with higher levels have less depression.
Dr. Sherwood Brown, senior author of the study, said “Our findings suggest that screening for vitamin D levels in depressed patients – and perhaps screening for depression in people with low vitamin D levels – might be useful.”
How Do I Get More Vitamin D?
Vitamin D is available from the sun, so try to be outdoors more often. Consider a more economical use of sunscreen as it prevents absorption of vitamin D more effectively than it prevents sunburn. Although sunscreen may prevent cancer, vitamin D deficiency may also contribute cancer risk.
According to the Journal Cancer, "much of the geographic variation in cancer mortality rates in the U.S. can be attributed to variations in solar UV-B radiation exposure. Thus, many lives could be extended through increased careful exposure to solar UV-B radiation and more safely, vitamin D3 supplementation, especially in non summer months."
Sunbathing carries a risk of skin cancer so it is best avoided. There are safer ways to enjoy the sun such as wearing loose clothing, wearing a sun hat, finding a shady spot and limiting your time in direct sunlight.
Vitamin D is available from limited food sources, such as:
UV-irradiated mushrooms
Eggs
Fish
Beef liver
Fortified breakfast cereals
Vitamin D is also available as a supplement
Sources:
Low vitamin D levels linked to depression, UT Southwestern psychiatrists report, Southwestern Medical Center Press Release, 5 January 2012. http://www.utsouthwestern.edu/newsroom/news-releases/year-2012/vitamin-d-brown.html
Suicide in the U.S.: Statistics and Prevention, National Institute of Mental Health. Web. 7 January 2012.
http://www.nimh.nih.gov/health/publications/suicide-in-the-us-statistics-and-prevention/index.shtml
Key Molecule in Inflammation-Related Depression Confirmed, National Institute of Mental Health. Web. 7 January 2012.
http://www.nimh.nih.gov/science-news/2009/key-molecule-in-inflammation-related-depression-confirmed.shtml
Vitamin D supplementation improves cytokine profiles in patients with congestive heart failure: a double-blind, randomized, placebo-controlled trial. Am J Clin Nutr. 2006 Apr;83(4):754-9. Abstract: http://www.ncbi.nlm.nih.gov/pubmed/16600924
Darkness at Noon: Sunscreens and Vitamin D3, Photochemistry and Photobiology, Volume 83, Issue 2, pages 459–463, March/April 2007. Abstract: http://onlinelibrary.wiley.com/doi/10.1562/2006-06-29-RC-956/abstract
An estimate of premature cancer mortality in the U.S. due to inadequate doses of solar ultraviolet-B radiation, Cancer, Volume 94, Issue 6, pages 1867–1875, 15 March 2002. Abstract: http://onlinelibrary.wiley.com/doi/10.1002/cncr.10427/abstract
Joanna is a freelance health writer for The Mother magazine and Suite 101 with a column on infertility, http://infertility.suite101.com/. She is author of the book, 'Breast Milk: A Natural Immunisation,' and co-author of an educational resource on disabled parenting.
Reviewed January 9, 2012
by Michele Blacksberg RN
Edited by Jody Smith