RESUMO
OBJECTIVE: Vitamin D is thought to be deficient in patients with bipolar disorder. The purpose of this study is to use latent profile analysis to identify the patterns of vitamin D levels in patients with episodes of bipolar depression, and to examine the relationship among these latent profiles and demographic and clinical characteristics. METHODS: A total of 149 patients diagnosed with bipolar depression were selected in Guangzhou, China. Depression was evaluated by Zung Self-Rating Depression Scale. Serum 25-hydroxyvitamin D levels tested at baseline and after two weeks of psychiatric treatment were included in the latent profile analysis to identify subgroups. P-trend analysis was used to assess the association between subgroups and depression improvement. Multinomial logistic regression analysis was used to assess the influencing factors of subgroups. RESULTS: A three-profiles solution was found to demonstrate the best fit [low-level profile (32.9%), medium-level profile (51.0%), and high-level profile (16.1%)]. There was a significant nonlinear relationship between depression improvement and vitamin D high-level profile, compared to medium-level profile (P for trend <0.05). In multinomial logistic regression analysis, baseline and post-treatment SDS scores, admission season, age, and body mass index significantly affect the profile membership. CONCLUSIONS: This study found that individuals with high levels of vitamin D showed a significant improvement in depression severity. However, those with low levels of vitamin D remained deficient, indicating a need for targeted vitamin D supplementation. Our findings may provide valuable insights for designing tailored vitamin D supplement interventions to address vitamin D deficiency in bipolar depression.