Tobacco smoke exposure is an independent predictor of vitamin D deficiency in US children.

IMPORTANCE:The role of tobacco-smoke exposure on serum vitamin D concentration in US pediatric population is not known. We hypothesized that tobacco smoke exposure would increase the prevalence of vitamin D deficiency in US children. METHODS:Representative national data were accessed from the National Health and Nutrition Examination Survey (NHANES) 2009-2010 databank on 2,263 subjects of ages 3 to 17 years. Subjects were categorized into two groups based on their age: children, if