Common Mental Disorders and Vitamin D Deficiency/Insufficiency: A Cross-Sectional Study Among Female Workers in Southern Brazil

<b>Background/Objectives</b>: The literature indicates that decreased vitamin D levels are frequently observed in individuals with severe psychiatric disorders. However, the scarcity of studies investigating this association in non-psychiatric populations, such as working women, limits the generalizability of these findings. Therefore, this study aimed to investigate the association between common mental disorders (CMDs) and vitamin D deficiency/insufficiency among female workers in southern Brazil. <b>Methods</b>: A cross-sectional study was conducted with a sample of 304 female workers from an industrial group in southern Brazil. Vitamin D deficiency/insufficiency was defined as a serum 25(OH)D concentration of <30 ng/mL. CMDs were assessed using the Self-Reporting Questionnaire (SRQ-20), with a cutoff score of ≥8. The association between CMDs and vitamin D deficiency/insufficiency was estimated using prevalence ratios (PRs) obtained through Poisson regression models adjusted for potential confounders. All analyses were stratified by age group (≤40 years and >40 years). <b>Results</b>: The ≤40-year group included 212 women (69.7%; mean age: 30.1 ± 6.3 years), and the >40-year group included 92 women (30.3%; mean age: 47.5 ± 5.6 years). The prevalence of vitamin D deficiency/insufficiency was 75.0% (95% confidence interval [CI]: 69.1-80.9) in women aged ≤40 years and 77.2% (95% CI: 68.4-85.9) in those aged >40 years. After adjustment for potential confounding variables, among women older than 40 years, those with CMDs had a 25% higher probability of presenting vitamin D deficiency/insufficiency compared to those without CMDs (PR = 1.25; 95% CI: 1.00-1.56; <i>p</i> = 0.044). Among women aged ≤40 years, no significant association was observed between CMDs and vitamin D deficiency/insufficiency (PR = 1.10; 95% CI: 0.94-1.30; <i>p</i> = 0.226). <b>Conclusions</b>: The findings of this study indicate a significant association between common mental disorders and vitamin D deficiency/insufficiency among female workers, particularly in those aged 40 years or older.