The Prevalence of Vitamin D Deficiency Among One to Six Year Old Children of Tehran, Iran

Background: Vitamin D has an essential role in bone growth and metabolism. Currently, its role has been investigated in different diseases. It is high prevalence of vitamin D deficiency in the world, particularly in developing countries. Objectives: The aim of this study is to investigate the prevalence of vitamin D deficiency in children of 1 - 6 years old and its relation with their age, sex and body mass index. Methods: This study was conducted in pediatric clinic of Javaheri Hospital in Tehran, from 2016 to 2017. The study population was children of 1 - 6 years old presenting to the pediatric clinic for routine examination or treatment. The collected data included age, gender, height, weight, and serum 25-hydroxy vitamin D level. Results: Of the total population of 288 children, 47.2% were female and 52.8% were male. The prevalence of vitaminDdeficiency was 51%, while 4.51% had severe deficiency (level of vitamin D < 10 ng/mL). The relation between the level of vitamin D and variables of gender, height, weight, and body mass index was not statistically significant. Nonetheless, the level of vitamin D had a statistically significant relation with age such that, serum level of 25(OH) vitamin D reduced by 3.47 ng/mL for every one year of age (P < 0.001). Conclusions: The prevalence of vitamin D deficiency is increasing with increasing age. Therefore, adoption of preventive and therapeutic measures is necessary to reduce its prevalence and side effects.