Assessment of Vitamin D Sufficiency in Different Age Groups of Children in Türkiye Using the Bhattacharya Method

Objective: Vitamin D plays a role in regulating mineral balance, particularly calcium and phosphate, and in promoting bone health.It is essential to have reliable age-specific reference values for vitamin D in order to make accurate clinical decisions.This study aimed to establish reference ranges for 25-hydroxyvitamin D [25(OH)D] levels in children aged 1-19 years in Trkiye using the Bhattacharya method and to assess vitamin D status across different age groups.Methods: Data from 243,906 [25(OH)D] measurements, collected from hospital laboratory records between 2019 and 2023, were analyzed. Results:The reference ranges for serum [25(OH)D] levels vary by age and gender.For children aged 1-2 years, the range is 24.5-56.6ng/mL, decreasing progressively to 16-42.9 ng/mL for ages 7-10 years.For women aged 11-15 years, the range is 14.8-35.5 ng/mL, and for ages 16-19 years, it is 15-39 ng/mL.For male patients, the ranges are slightly higher: 15.6-40.7 ng/mL for ages 11-15 years and 15.8-39.3ng/mL for ages 16-19 years.The study revealed that the prevalence of [25(OH)D] deficiency levels below 12 ng/mL (considered deficient based on the institute of medicine criteria) increased with age among children and adolescents.This trend underscores a notable rise in deficiency rates after early childhood, peaking during adolescence. Conclusion:The results provide significant insights into the vitamin D status of the pediatric population in Trkiye.The findings emphasise a decline in vitamin D levels with age and indicate that the highest prevalence of deficiency is seen in adolescents.