Effect of vitamin D supplemention on depression – none
Effect of vitamin D supplement on depression scores in people with low levels of serum 25-hydroxyvitamin D: nested case-control study and randomised clinical trial
Kjærgaard M, Waterloo K, Wang CE, Almås B, Figenschau Y, Hutchinson MS, Svartberg J, Jorde R.
Reference : Br J Psychiatry. 2012 Nov;201(5):360-8. doi: 10.1192/bjp.bp.111.104349. Epub 2012 Jul 12.
I guess you wouldn’t be surprised if people in Norway had lower levels of Vitamin D than people in sunnier climates.
In this RCT, people with lowish Vit D levels (less than 55 nmol/L) were more likely to be depressed. Perhaps the depressive symptoms made them more likely to stay inside.
After six months, supplementation did improve Vit D scores to ‘normal’, but had no significant affect on depression when compared with a placebo group. Happily, both placebo and treatment arms improved.
Conclusion:
“Low levels of serum 25(OH)D are associated with depressive symptoms, but no effect was found with vitamin D supplementation”