The evidence for the association between vitamin-D deficiency and depression, although equivocal, has been established in several populations in different countries and supported by meta-analytical studies1. Much of the evidence for this comes from Western countries2. Similarly, the evidence for the benefits of supplementation, although shown, also comes from similar populations and is equivocal3. Need for data from different populations and for randomized controlled trials to establish causality is stressed by most researchers. This study aims for presentation reviews of the association between vitamin-D and depression in the GCC, using the publicly available data of Our World in Data.

The statistical analysis used median prevalence depressive disorders data (from 1990–2019) in the GCC countries (both sex and age-standardized (%)), which was downloaded from Our World in Data and was last updated on August 28, 2022. Vitamin D deficiency data were collected through a literature review search using PubMed and Google Scholar. A linear regression model was performed with the median prevalence of depressive disorders data as an outcome. The prevalence of vitamin-D deficiency, population median age and the interaction term between prevalence of vitamin-D deficiency and population median age were used as predictors. The effects of prevalence of depressive disorders both sex age standardized (AS) percentage (%) were estimated with 95% confidence interval (95% CI) using bootstrap covariance matrix estimator. Fitted model's likelihood ratio chi-square (LR χ2) test with corresponding p-value was computed and reported.

A positive association was observed between the median prevalence of depressive disorders and the prevalence of vitamin-D deficiency, adjusted for population median age, were observed (LR χ2 p-value = 0.005) and adjusted R2 = 0.706.

Prevalence of depressive disorders was associated with prevalence of vitamin D deficiency among the population of GCC countries. Future randomized control trials on Vitamin D supplementation are needed to confirm these observations.