Effect of Vitamin D Supplementation on Depression in African Americans with Type 2 Diabetes.
Hooke, Patrick   (Washington University in St Louis)
Mentor: Bernal-Mizrachi, Carlos (Washington University in St Louis)
Vitamin D deficiency has been linked to depression in a population with cardiovascular disease, and depression has been linked to patients with type 2 diabetes mellitus (T2DM). Unfortunately, little research has focused on the relationship between cardiovascular disease, type 2 diabetes mellitus, and the replacement of vitamin D. T2DM and depression each affect roughly 250 million people globally; within that population, African-Americans have an increased prevalence of both T2DM and vitamin D deficiency, as well as higher rates of depression when compared with Caucasians. Therefore, we evaluated whether vitamin D3 supplementation in vitamin D-deficient African Americans with T2DM will reduce depression symptomatology with our randomized, double-blinded, controlled trial of vitamin D3 4,000 IU/day vs. 600 IU/day. In a patient population of 72, patients were allocated to 4,000 IU/day or 600 IU/day of vitamin D3 at a 1:1 ratio. The duration of the study was 1 years; subjects had 6 total study visits at baseline, then 1, 3, 6, 9, and 12 months. Patients completed a patient health questionnaire (PHQ-9) at baseline and every 3 months until the end of the study. We found no differences in BMI, vital signs, plasma or urine calcium, fasting glucose, A1C, and lipid levels when comparing subject baseline to one year of treatment. Interestingly, both groups achieved normal 25(OH) vitamin D levels (Group A: 18 ng/mL ? 44 ng/mL and Group B: 20 ng/mL ? 31 ng/mL). Sub-analysis of participants who demonstrated at least minimal depressive symptoms at baseline in both groups revealed a decrease in PHQ-9 scores (10.7 ? 7.6; p= 0.05) concurrently with an increase in plasma 25(OH) vitamin D levels (15.6 ng/mL ? 37.3 ng/mL). These results suggest that achieving 25(OH)D level greater than 30 ng/mL with vitamin D supplementation in vitamin D-deficient African Americans with type 2 diabetics might improve symptoms of depression but larger randomized controlled trials are needed.