Vitamin D supplements reduce depressive symptoms and cardiac events in heart failure patients with moderate to severe depressive symptoms

Background: Depressive symptoms and vitamin D deficiency predict cardiac events in heart failure patients, but whether vitamin D supplements are associated with depressive symptoms and cardiac events in heart failure patients remains unknown. Purpose: The purpose of this study was to compare the association of vitamin D supplement use with depressive symptoms and cardiac events in heart failure patients with mild or moderate to severe depressive symptoms. Methods: A total of 177 heart failure patients with depressive symptoms (Patient Health Questionnaire-9 score 5) completed a three-day food diary to determine dietary vitamin D deficiency. Patients were split into four groups by dietary vitamin D adequacy versus deficiency and vitamin D supplement use versus non-use. The Patient Health Questionnaire-9 was used to reassess depressive symptoms at six months. Data on cardiac events for up to one year and vitamin D supplement use were obtained from patient interview and medical record review. Hierarchical linear and Cox regressions were used for data analysis. Results: Sixty-six patients (37.3%) had dietary vitamin D deficiency and 80 (45.2%) used vitamin D supplements. In patients with moderate to severe depressive symptoms, the group with dietary vitamin D deficiency and no supplements had the highest Patient Health Questionnaire-9 score at six months (=0.542, p<0.001) and shortest cardiac event-free survival (p<0.001) among the four groups, the group with dietary vitamin D deficiency and no supplements didn't have the highest Patient Health Questionnaire-9 score at six months and shortest cardiac event-free survival in patients with mild depressive symptoms. Conclusions: Vitamin D supplements predicted lower depressive symptoms and reduced cardiac events for patients with moderate to severe depressive symptoms. Vitamin D deficiency was associated with higher risk of shorter cardiac event-free survival in heart failure patients regardless of vitamin D supplementation.