Feeling depressed can be a sign of vitamin D deficiency, research finds.
The study of 12,600 people analysed their vitamin D levels and any symptoms of depression.
The results showed that people who were more depressed had lower vitamin D levels.
As well as low mood, the most important symptoms of depression are:
- Decreased interest in life or pleasure.
- Energy loss.
- Concentration problems.
Foods that are rich in vitamin D include oily fish and eggs, but most people get their vitamin D from the action of sunlight on the skin.
That is why levels are typically lower in the body through the winter months in more Northern climes.
Up to 50% of young women may be deficient in this vitamin, other research has shown.
The study’s authors write that:
“We found that low vitamin D levels are associated with depressive symptoms, especially in persons with a history of depression.
These findings suggest that primary care patients with a history of depression may be an important target for assessment of vitamin D levels.”
The study does not tell us whether vitamin D deficiency causes depression or results from it.
However, vitamin D may affect critical neurotransmitters and inflammatory markers.
Vitamin D levels are now routinely tested during physical exams as deficiencies are linked to other health problems, such as obesity, diabetes and general cognitive decline.
Professor E. Sherwood Brown, study co-author, 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.
But we don’t have enough information yet to recommend going out and taking supplements.”
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The study was published in the journal Mayo Clinic Proceedings (Hoang et al., 2011).