Vitamin D Deficiency and Depression in Obese Adults: A Case- Control Study 

Abstract

Background: Depression is one of the most prevalent psychiatric disorders reported in obese population. Amongst the contributing factors of depression, vitamin D deficiency has increasingly drawn attention in recent years. This paper seeks to examine the association between serum vitamin D level and depression in patients with obesity.Methods: This case-control study included 173 depressed obese patients and 174 non-depressed controls. Structured Clinical Interview for DSM-5 (SCID-5) was used to confirm the diagnosis of depression. 25-Hydroxyvitamin D [25(OH)D], Thyroid stimulating hormone (TSH), fasting blood sugar (FBS), parathyroid hormone (PTH) levels, and BMI were assessed in both groups. The statistical analyses included T-test, Chi-squared test, and multivariable logistic regression.Results: The mean 25(OH)D levels were significantly different between the case and control groups (20.43 ± 15.37 vs. 26.55 ± 13.17, P < .001). Vitamin D insufficiency/deficiency was detected in 77.6% and 67.4% of the case and control groups, respectively, which was significantly different (P = .034). Being female, greater age and lower vitamin D levels were associated with greater odds of developing depression (OR = 3.57, 95% CI = 1.82-7.02; OR = 1.05, 95% CI = 1.02-1.07; OR = 1.51, 95%CI = 1.16-1.96, respectively).Conclusion: The present study provides additional evidence with respect to the hypothesis that low vitamin D serum concentration is associated with depression in obese adults, and highlights the need for further research to determine whether this association is causal.