Factor Affecting the Vitamin D Status in South Korean Children

Abstract

To establish the prevalence of vitamin D deficiency and insufficiency in healthy South Korean children aged between 1 month and 16 years and to identify factors affecting the serum vitamin D levels in South Korea. A total 969 healthy children were enrolled in this study. Serum levels of 25 hydroxyvitamin D (25(OH)D), calcium, phosphorous and alkaline phosphatase (ALP) were measured during a 1 year period. All the children were divided into four groups depending on the age. The prevalence of vitamin D deficiency (<15 ng/mL) was 20.5% and that of vitamin D insufficiency (15-20 ng/mL) was 19.5%. Overall, the mean serum 25(OH)D levels was 22.9±9.9 ng/mL. They were the highest in the preschoolers (2-5 years, 24.4 ng/mL) and the lowest in the adolescents (11-16 years,15.9 ng/mL). In addition, they were significantly higher in summer as compared with winter. There were eight cases of subclinical rickets with elevated serum ALP levels. The prevalence of vitamin D insufficiency and deficiency was relatively higher in our series of children. It is imperative that the public policies be established to provide vitamin D supplementation for South Korean children. In addition, pediatricians should consider such factors as the body mass index, sex, season and other risk factors when determining the optimal level of vitamin D.