Vitamin D, Parathormone and Associated Minerals among Students in Zagazig District, Sharkia Governorate, Egypt.

Aim: To determine the prevalence of vitamin D deficiency and associated factors among students of age 13 - 18 years. Methods: Design: Community-based cross sectional survey. Setting: Two schools were selected using multistage sampling techniques. Sampling: Cluster sampling of all enrolled students (550 students). Outcome Measures: Serum levels of 25-hydroxyvitamin D (25 OHD), parathyroid hormone and calcium. Data was collected about nutritional intake, physical activity and lifestyle variables that are potential risk factors for hypovitaminosis D. Results: Hypovitaminosis D prevalence was 23.8 %, of which 5.3 % was deficiency and 18.5 % insufficiency. Serum 25 OHD levels inversely correlated with parathyroid hormone levels (r = -0.206, P = 0.00). Low calcium and ionized calcium levels were 40.6 % and 45.9 %, respectively, and significantly correlated with vitamin D levels. Female students have significantly higher levels of hypovitaminosis D compared to males (29.3 % to 15.0 %, respectively) and the level...