Contributions of Vitamin D in the management of depressive symptoms and cardiovascular risk factors: study protocol for a randomized, double-blind, placebo-controlled clinical trial

Abstract

Background: Depression is a major cause of chronic disability throughout the world and an important cardiovascular risk factor, increasing the relative risk of coronary artery disease as well as rates of cardiovascular morbidity and mortality. Concomitant to the greater prevalence of depression, there has been a reduction in exposure to sunlight with the increase in urbanization and the use of sun block, which has led to a reduction in serum levels of 25-hydroxyvitamin D. Therefore, this paper describes a protocol for a clinical trial aimed at evaluating the effects of vitamin D supplementation on depression and cardiovascular risk factors to contribute evidence regarding the potential influence of supplementation in situations related to mood regulation. Methods: This protocol study was guided by the SPIRIT recommendations. A randomized, placebo-controlled, double-blind trial will be conducted with 224 adults (age range: 18 to 59 years) with depression taking antidepressants with no history of vitamin D supplementation, psychiatric comorbidities, chronic kidney disease, hypercalcemia or neoplasm in care at psychiatric outpatient clinics of two universities in northeast Brazil. Eligible participants who provided written consent will be randomly designated to either the intervention group (n = 112; vitamin D supplementation – 50,000 IU per week for six months) or control group (n = 112; placebo taken weekly for six months). Measures for monitoring depressive symptoms, clinical trials and laboratory tests for evaluating cardiovascular risk factors and serum vitamin D levels will be performed before and after the intervention period. Discussion: To the best of our knowledge, this will be the first clinical trial with the aim of testing the effectiveness of vitamin D supplementation on the reduction in cardiovascular risk and as an adjuvant to depression therapy for a prolonged period (six months). The findings will contribute to the understanding of the therapeutic effects of vitamin D supplementation on the management of depression and can help guide public policies directed toward vitamin supplementation for the reduction of cardiovascular risk. Trial registration: Proof: http://www.ensaiosclinicos.gov.br/rg/. Number: RBR-6yj8sj / UTN Number: U1111-1217-9237 (July 23, 2018)