Associations of Dietary Vitamin A and Beta-Carotene Intake With Depression. A Meta-Analysis of Observational Studies

Objective To clarify the associations of dietary vitamin A and beta-carotene intake with depression based on a meta-analysis of observational studies. Methods An extensive literature search on February 2022 (PubMed, Web of Science and Embase) was employed to identify observational studies on the associations of dietary vitamin A and beta-carotene intake with depression. The pooled relative risk (RR) of depression for the highest vs. lowest dietary vitamin A and beta-carotene intake category, and the standard mean difference (SMD) of dietary vitamin A and beta-carotene intake for depression vs. control subjects, were calculated. Results A total of 25 observational studies (100,955 participants), which included 24 cross-sectional/case-control and 1 prospective cohort study, were included in this study. The overall multi-variable adjusted RR demonstrated that dietary vitamin A intake was inversely associated with depression (RR= 0.83, 95%CI: 0.70–1.00;P= 0.05). In addition, the combined SMD showed that the dietary vitamin A intake in depression was also lower than that in control subjects (SMD = −0.13, 95%CI: −0.18 to −0.07;P< 0.001). On the other hand, the overall multi-variable adjusted RR indicated that dietary beta-carotene intake was negatively associated with depression (RR= 0.63, 95%CI: 0.55–0.72;P< 0.001). The combined SMD showed that the dietary beta-carotene intake in depression was also lower than that in control subjects (SMD = −0.34, 95%CI: −0.48 to −0.20;P< 0.001). Conclusion Our results suggest that both dietary vitamin A and beta-carotene intake is inversely associated with depression. However, due to the limited evidence, further prospective cohort studies are still needed.