No Effect of Vitamin D on Depressive Symptoms


Am Fam Physician. 2014 Jan 15;89(2):131-136.

Clinical Question

In patients with low vitamin D levels, does vitamin D supplementation improve symptoms of depression?

Bottom Line

Taken in aggregate, symptoms of depression do not improve in patients with low vitamin D levels when given vitamin D supplementation any more than when given placebo. There may be a benefit in patients with low vitamin D levels and mild to moderate depression. (Level of Evidence = 1b–)


This study was conducted in Norway, where researchers started by identifying patients with depressive symptoms and low vitamin D levels (< 22 ng per mL [< 55 nmol per L]). The authors excluded patients with severe depression (who were sent for treatment). The remaining 243 patients had a range of depression scores, although the percentage with mild to moderate depression was not reported. These patients were randomized, using concealed allocation, to receive oral placebo or cholecalciferol at a dosage of 40,000 IU weekly. After six months, vitamin D levels increased to normal in 97.5% of treated patients but in only 1.6% of the placebo group. However, there were significant improvements in depression scores in both groups, including an increase in global seasonality score, a measure of seasonal affective disorder. Patients with higher depression scores (who met the definition of depressive disorder) at the start of the study may have had a greater improvement in depression scores with treatment than patients receiving placebo, although this result needs to be confirmed by other studies.

Study design: Randomized controlled trial (double-blinded)

Funding source: Government

Allocation: Concealed

Setting: Outpatient (primary care)

Reference: Kjærgaard M, Waterloo K, Wang CE, et al. 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. Br J Psychiatry.. 2012; 201( 5): 360– 368.

POEMs (patient-oriented evidence that matters) are provided by Essential Evidence Plus, a point-of-care clinical decision support system published by Wiley-Blackwell. For more information, please see http://www.essentialevidenceplus.com. Copyright Wiley-Blackwell. Used with permission.

For definitions of levels of evidence used in POEMs, see http://www.essentialevidenceplus.com/product/ebm_loe.cfm?show=oxford.

To subscribe to a free podcast of these and other POEMs that appear in AFP, search in iTunes for “POEM of the Week” or go to http://goo.gl/3niWXb.



Want to use this article elsewhere? Get Permissions

More in AFP

Editor's Collections

Related Content

More in Pubmed


Sep 2021

Access the latest issue of American Family Physician

Read the Issue

Email Alerts

Don't miss a single issue. Sign up for the free AFP email table of contents.

Sign Up Now

Navigate this Article