Low serum 25-hydroxyvitamin D levels are associated with depression in an adult Norwegian population.

Kjærgaard M, Joakimsen R, Jorde R.
Psychiatry Res. 2011 Jul 22.

Observational and intervention studies have suggested an association between low levels of 25-hydroxyvitamin D (25(OH)D) and depressive symptoms in several subgroups of disease and age. This study tests the hypothesis in a general population. Our data are based on 10,086 persons who participated in the sixth Tromsø study carried out in 2007-2008. Depressive symptoms were evaluated using Hopkins Symptoms Check List 10 (SCL-10) based on answers from a questionnaire.

Results were adjusted for known confounders such as age, gender, BMI, physical exercise, alcohol, education, marital status, kidney function and chronic disease.
Results are presented for smokers (N=1966) and non-smokers (N=8120) separately as our immunoassay seems to overestimate 25(OH)D levels for smokers.

Low serum 25(OH)D levels were found to be a significant predictor of depressive symptoms in both smokers and non-smokers (P<0.01).

The association seemed to be stronger in women.

Odds ratio for depression in the highest 25(OH)D quartile was

• 0.59 (0.39-0.89) in smokers and
• 0.74 (0.58-0.95) in non-smokers

compared to the lowest quartile.
However, no conclusions with regard to causality can be drawn due to the cross-sectional design of the study.

Copyright © 2011 Elsevier Ltd. All rights reserved. PMID: 21784535
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Smokers had 36% increased chance of depression

(Smokers 41% less X 1966 + Non-smokers 25% less X 8120)/2 X (1966+8120)

Even more for women - wonder how much

Wish that the abstract stated the vitamin D levels

See also Vitamin D Life

• Smoking reduces vitamin D
• The influence of smoking on vitamin D status and calcium metabolism file
• A review of the critical role of vitamin D in the functioning of ... file
• Google site search of Vitamin D Life smoke OR smoking : 609 hits July 2012
• Pancreatic cancer vitamin D smoking and diabetes – Aug 2010
• Speculation on vitamin D and smoking during pregnancy - June 2010
• All items in Winter Blues/Depression and Vitamin D 36 items as of Feb 2012
• Depressed people had less than 10 ng of vitamin D – July 2010
• vitamin D variations and mental health - Aug 2010 nice charts
• Depression in UAE peaks in the summer – probably due to sun avoidance – Feb 2011
• Several abstracts on vitamin D and depression – Y or N July 2010
• Less than 20 ng vitamin D increases depression by 80 percent – Dec 2010
• Hypothesis non-severe depression and diabetes related by low vitamin D – June 2011
• Depression 40 percent more likely if low vitamin D – Oct 2011
• Teens no longer depressed after vitamin D raised to 36 ng – Feb 2012
• Depression not reduced with 5700 IU vitamin D daily average – July 2012 later study, also by Kjærgaard