Major factors of hypovitaminosis D in unsupplemented children aged 6-12 years in an urban environment of Algiers

Introduction. Hypovitaminosis D is a global public health problem. It affects children of all ages. Objective. To determine the risk factors of hypovitaminosis D in children. Population and methods. Cross-sectional study of non-supplemented children (n=123), 54 girls, and 69 boys, aged between 6-12 years. The thresholds were defined as adequacy 30 ng/mL, and deficiency 10 ng/mL. Seasons, daily sunshine duration, gender, exogenous Vit. D intakes, phototype, and body mass index (BMI) were analysed. The study was carried out during 12 months (January 2018-January 2019) with samples taken during the four seasons. Results. The median age was 8.16 ±1.82 years. Hypovitaminosis D was noted in 79.6% versus 20.4% adequacy. The average BMI was 16.80 ± 3.29kg/m2 [11.89 -30.70]. Vit. D daily intakes < 400 IU/d was noted in 52.9% of children, 75.6% of them were insufficiently exposed to sun. After multivariate analysis, and adjustment, the influencing factors were seasons (pa <0,0001, OR=11.22), and sun exposure (pa <0,001, OR=3.56). The lowest rates were present in winter, and when sunshine was < 30 min/d. There was a significant negative correlation between Vit. D values and parathormone (PTH) rate (p <0,001, r= -0.49). Conclusion. There is a high prevalence of hypovitaminosis D in scholar age children. Sun exposure could be insufficient in this urban city. Children should have adequate outdoor activities with sunlight, according to Word Health Organization (WHO) recommendations. Vit.D supplementation should be intensified, especially in winter, and diet should be enriched in Vit. D