Prevalence and risk factors of vitamin D deficiency among Afghan primary school children.

Vitamin D deficiency is common in many societies and causes rickets and non-skeletal disorders in children. There are no published data on vitamin D deficiency in Afghanistan. We, therefore, investigated the prevalence and associated factors of vitamin D deficiency in Afghan school children in Kandahar City, Afghanistan. This cross-sectional analytical study was conducted from September 2022 to April 2023 in 510 primary school students aged 6-15 years from six randomly selected schools. Data were analyzed by using descriptive statistics, Chi-square test, and multivariate logistic regression. Of the 510 enrolled children, 54.3% were boys and 91.8% were poor. The mean serum 25(OH)D concentration was 9.3 ng/mL. Vitamin D deficiency (< 20 ng/mL) was detected in 436/510 (85.5%) children that was severe in 267/510 (52.4%). By logistic regression analysis, independent factors for vitamin D deficiency were: (i) older age group 11-15 vs. 6 - 10 years, adjusted odds ratio (AOR) 2.8 (95% confidence interval 1.2-6.2), (ii) poverty AOR 2.0 (1.0-4.3), (iii) not doing outdoor physical activity AOR 4.8 (2.8-8.1), and (iv) daily sunlight exposure < 60 min AOR 2.2 (1.3-3.7). Although Kandahar is very sunny throughout the year, vitamin D deficiency is highly prevalent among school boys and girls, placing them at great risk of vitamin D-deficient rickets. More work is needed to define the country-wide prevalence of vitamin D deficiency to inform robust strategies of vitamin D supplementation, the provision of vitamin D-fortified food to the school children in Kandahar City and health education programs that can be conducted with the help of international organizations.