The new study included about 12,600 people aged 20 to 90. Researchers measured the vitamin D in their blood and reviewed symptoms of depression.
People with the lowest levels of vitamin D were more likely to report symptoms of depression, compared to people with higher blood levels of vitamin D. This association was strongest among people with a history of depression.
In the last couple of years, vitamin D deficiency has been linked to a host of conditions, including heart disease,diabetes, osteoporosis,certain cancers, & autoimmune diseases such as multiple sclerosis.
The Institute of Medicine recommends that people aged 1 to 70 take 600 international units (IUs) of vitamin D per day, and people older than 71 should aim for 800 IUs. (vitamin D recommendations were recently raised.)
Depression Linked to Low Vitamin D
Exactly how depression & vitamin D may be linked is unclear. Vitamin D deficiency may result in depression, or depression may increase risk for low vitamin D levels.
For example, depressed people may spend more time indoors, are less likely to eat a healthy diet & take care of themselves, all of which could affect vitamin D levels. On the other hand, there are vitamin D receptors everywhere in the body, including the brain. These receptors need vitamin D to do their job.
The new findings (which appear in Mayo Clinic Proceedings) “add depression to the spectrum of medical illnesses associated with low vitamin D, and people with depression probably should consider a blood test to see if their vitamin D is low and whether supplements may be needed,” says researcher E. Sherwood Brown, MD, PhD, a professor of psychiatry at the University of Texas Southwestern Medical Center in Dallas.
Other studies on the link between low vitamin D & depression have yielded mixed results, but most have pointed toward a connection. The new study is among the largest to date, and shows that the two may indeed be linked.
Some foods like fish and fortified dairy products are rich in vitamin D. These D-rich foods are few and far between, which is why many people recommend supplements of vitamin D.
Robert Graham, MD, routinely discusses vitamin D with his patients. He is an internist at Lenox Hill Hospital in New York City. He says, “It makes sense to me that vitamin D deficiency is correlated with depression or anxiety. I would check patients who are showing signs of depression and if they are deficient in vitamin D, it makes sense to supplement.”
Whether low vitamin D is causing depression or if loading up on vitamin D can help a person feel better is not known.
Web MD Health News
11 January, 2012