Prevalence of hypovitaminosis D and associated factors in adolescent students of a capital of northeastern Brazil

Background: Hypovitaminosis D is a frequent problem in the world and can be influenced by several factors. Objective: To estimate the prevalence of hypovitaminosis D and associated factors in adolescent students of a capital city of northeastern Brazil. Methods: Cross-sectional epidemiological study assessing 220 school adolescents of both sexes aged 15 to 19 years. A questionnaire was applied to assess sociodemographic (skin color, mother’s education and receiving social benefits) and behavioral data (number of hours of sleep per day, sun exposure, physical activity and dietary vitamin D intake). Anthropometric nutritional status was assessed by BMI (body mass index) for age. Serum 25 (OH) D concentrations, PTH and serum calcium were measured by blood samples. We identified individuals with hypovitaminosis D as those with 25 (OH) D < 30 ng/dL. The analysis of factors associated with hypovitaminosis D was performed by simple and multivariate Poisson Regression. Results: The prevalence of hypovitaminosis D was 57.3%. The female population had a significantly higher prevalence than the male. In the final adjusted model, the variable independently associated with hypovitaminosis D in females was the lowest serum calcium concentrations, and for males it was BMI, in which adolescents who had overweight/obesity were 2.4 times more likely to have hypovitaminosis D than the eutrophic ones. Conclusions: The present study found a high prevalence of hypovitaminosis D in the analyzed population, especially in female adolescents. In addition, the factors independently associated with hypovitaminosis D were found to be overweight/obese in boys and low calcium concentrations in girls.