Correlation between levels of 25-hydroxy vitamin D and seasons in 0-5 years old children in Nanjing area

Abstract

Objective To analyze the level of 25-hydroxy vitamin D [25-(OH)D]in serum from 0 to 5 years old children in Nanjing area so as to provide some guides on clinical application. Methods The serum 25-(OH)D level was detected by using enzyme-linked immunosorbent assay kit in children from 0 to 5 years old that took health examination in Nanjing Maternal and Child Health Hospital Affiliated to Nanjing Medical University from June 2013 to May 2014.The average vitamin D levels and deficiency rates were analyzed, and the factors such as age, sex and season which might induce vitamin D deficiency were analyzed. Results The average 25-(OH)D level in serum was (81.5±30.4) nmol/L, with a deficiency rate of 9.5%(271/23 944 cases). Among them, the 25-(OH)D level of boys was (81.9±31.6) nmol/L, while for girls it was (81.3±29.8) nmol/L.The main vitamin D deficiency ages of children were more than 4 to 5 years old.Vitamin D in male children [(64.9±21.2) nmol/L] was higher than female children [(60.8±21.2) nmol/L] (t=0.98, P<0.05) and vitamin D levels were influenced by seasonal variation.Vitamin D level of the third quarter [(108.1±11.6) nmol/L]was significantly higher than other quarters[(71.8±15.6) nmol/L, (95.5±21.2)nmol/L, (86.6±3.5) nmol/L] (F=4.53, P=0.03). Conclusions As a vital nutrient, the supplementation of vitamin D should be carried out in different development periods of the children and the supplement should also be based on local seasonal changes. Key words: 25-hydroxy vitamin D; 0-5 years old children; Changes of season