Vitamin D Deficiency in Children and Adolescents: Role of Puberty and Obesity on Vitamin D Status

Background: Vitamin D deficiency is common among children and adolescents and can be affected by several factors such as puberty and obesity. Objective: The aim of this study was to evaluate vitamin D status in children and adolescents and to analyse the influence of puberty and obesity on its level. Method: A cross-sectional study was carried-out, in which clinical and biochemical data were gathered from 384 healthy children and adolescents between May 2019 to May 2020. Results: 220 females and 164 males were enrolled (aged 7-16 years; mean ± SD: 11 ± 2.5). Vitamin D deficiency was found in 49% of the total cases and was significantly more prevalent in females than males (33.1% in female; 15.9% in male, P < .001). Mean vitamin D level was lower in obese children compared with non-obese (P < .001). Non-obese group had significantly higher levels of vitamin D in Tanner stage IV of puberty than obese individuals (20.1 ± 17.0 vs 5.4 ± 2.0) (P = .03). Vitamin D levels were significantly lower in females than males only in Tanner stage II (12.3 ± 9.0 vs 19.6 ± 16.6) (P = .005). The lowest level of Vitamin D was in Tanner stage Ⅳ-Ⅴ in boys and in Tanner stage Ⅱ-Ⅲ in girls (P < .001). Conclusion: Puberty is an additional risk factor for vitamin D deficiency especially in girls and obese children. This increased risk, together with the fact that most important time for building a proper skeleton is during childhood and adolescent, makes it essential to monitor vitamin D in these age groups.