Effects of Vitamin D supplementation on cardiovascular risk factors in shift workers: Study protocol for randomized, double-blind, placebo-controlled clinical trial

Abstract

Objective:The present clinical study aims to describe protocol to evaluate the effects of vitamin D3 supplementation on the cardiovascular risk factors in a population of rotating shift workers.Design:A randomized, double-blind, placebo-controlled, parallel group clinical trial testing 2 oral dosages of cholecalciferol (14,000 IU and 28,000 IU per week) for 12 months.Setting:The primary outcome for evaluation is an 18% reduction in hypertriglyceridemia (≥150mg/dL) between pre and postintervention measurements. Baseline characteristics of the study population will be summarized separately within each randomized group, and will use tests for continuous and categorical variables. For all tests, a P