WORKERS WITH LONG HOURS OF WORK IN CLOSED ENVIRONMENTS ARE MORE VULNERABLE TO VITAMIN D DEFICIENCY

Abstract

The objective was to estimate the prevalence of vitamin D deficiency and associated biological and social factors. This was a case series study involving 91 workers. Participants were categorized according to their indoor work schedule—either alternating day shifts (12/36-hour rotation) or fixed daily shifts (9 hours and 48 minutes)—and underwent data collection, which included sociodemographic and occupational assessments, a triplicate 24-hour dietary recall, and biochemical testing. Poisson regression analysis was performed. The prevalence of vitamin D deficiency was 16.5% (n=15). Significant associations were found between vitamin D status and length of service (χ²= 4.50; P= 0.034), work schedule (χ²= 23.60; P= 0.001), and sun exposure while commuting to work (χ²= 6.53; P= 0.011). In the regression analysis, only the fixed daily shift schedule remained significantly associated with vitamin D deficiency; workers on this schedule were 1.33 times more likely to exhibit the deficiency (P= 0.001) than those on the alternating shift schedule. While the prevalence of vitamin D deficiency is considered low, the fixed daily shift schedule proved to be a risk factor for the deficiency.