Vitamin D Status in an Italian Pediatric Cohort: Is There a Role for Tobacco Smoking Exposure?

Objective: Vitamin D deficiency is a common public health issue worldwide. The purpose of this study was to investigate the vitamin D status and its potential determinants in children residing in Sardinia (40 degrees N), Italy. Methods: Children were enrolled over a 12-month period. Serum 25(OH)D was measured by an immunochemiluminescence assay. A questionnaire was used to gather information on other variables, including passive smoke exposure. Results: A total of 182 children (males: 51.7%; median age: 9 years) were included. Mean +/- standard deviation serum 25(OH)D was 25.2 +/- 8.3 ng/mL for the whole group. The majority (n=123, 67.6%) had vitamin D sufficient values >20 ng/mL, while 32.4% (n=59) had vitamin D insufficient/deficient values (<= 20 ng/mL). Among the variables investigated, passive smoke exposure was significantly associated with insufficient 25(OH)D levels (p<0.0001). Conclusion: Our results confirm that hypovitaminosis D is common in Italian children. Furthermore, passive smoke exposure was identified as a significant risk factor for hypovitaminosis D.