Vitamin D and Depression: A Systematic Review and Meta-Analysis
Cheng YC, Huang YC, Huang WL
Critical Reviews in Food Science and Nutrition • February 2022
Plain Language Summary
This review of 41 clinical trials found that vitamin D supplements can help reduce symptoms of depression, especially in people who have clinical depression or who are deficient in vitamin D. Taking at least 2000 IU daily appears to be most effective. While not a replacement for standard depression treatment, vitamin D may be a helpful addition to mental health care.
Key Findings
- 1Vitamin D supplementation significantly reduced depressive symptoms (SMD = -0.317, p < 0.001)
- 2Effects were stronger in clinically depressed individuals
- 3Daily doses of 2000+ IU showed greater benefits
- 4Deficient individuals showed most improvement
Abstract
This meta-analysis evaluated randomized controlled trials investigating vitamin D supplementation for depression. Results from 41 RCTs demonstrated that vitamin D supplementation significantly reduced depressive symptoms compared to placebo.
Study Limitations
- Varying doses and durations across studies
- Different depression assessment tools used
- Not all studies included clinically depressed populations