Prevalence of vitamin D deficiency and its related factors in children and adolescents living in North Khorasan, Iran

Introduction: Vitamin D deficiency is recognized as an epidemic among children. The present study has analyzed serum 25 hydroxyvitamin D [25(OH)D] levels of children living in the city of Bojnurd, located in the North Khorasan province of Iran. Methods: In this cross-sectional study, 361 subjects (175 boys and 186 girls) aged 7-18 years participated; 25(OH) D, parathyroid hormone (PTH), and anthropometric measurements were obtained. Deficiency, insufficiency and sufficiency of vitamin D was assessed based on the relationship between 25(OH) D and PTH. Vitamin D status was reported according to gender and age group of participants. Results: The prevalence of vitamin D deficiency was 16.1% and its insufficiency was 25.2%. Girls had higher levels of vitamin D deficiency (30.6%) and insufficiency (38.7%). The mean level of serum 25(OH)D decreased in older age groups. The age-adjusted odds of serum 25(OH)D <30 was 21.12 higher in girls compared to boys. Conclusion: The prevalence of vitamin D deficiency and insufficiency was high. The ratio in girls was higher than in boys.