Status and influential factors of vitamin D among children aged 0 to 6 years in a Chinese population.
BACKGROUND
Vitamin D insufficiency and deficiency in childhood are common. However, the status and influential factors of vitamin D during different ages are not clear. This study aimed to survey vitamin D concentrations in children aged 0 to 6 years and explore its influential factors.


METHODS
A total of 6953 children were recruited in Wuxi City of East China from January to December in 2016. Enzyme-linked immunosorbent assay was used to determine the serum concentrations of 25-hydroxyvitamin D [25(OH)D].


RESULTS
The median vitamin D concentrations in the infant group (0-1 years of age) was 69.40 nmol/L, which were higher than that in both the toddlerhood group (1-3 years of age; 62.30 nmol/L) and the preschool group (3-6 years of age; 50.85 nmol/L). In addition, the median vitamin D concentrations were 71.70 nmol/L in summer, which was higher than that in spring (64.25 nmol/L), autumn (62.95 nmol/L) and winter (64.10 nmol/L). However, no difference was observed between genders (P = 0.974). Furthermore, the prevalence of vitamin D deficiency (< 50 nmol/L) was 48.1% in the preschool group (3-6 years of age), which was higher than the 21.2% vitamin D deficiency in the toddlerhood group (1-3 years of age) and the 17.9% vitamin D deficiency in the infant group (0-1 years of age). Interestingly, a nonlinear association between 25(OH) D and air temperature was observed.


CONCLUSIONS
A high prevalence of vitamin D deficiency was common in a Chinese population of children 0-6 years old, especially in the preschool-aged children. Therefore, we suggested that we should pay more attention to vitamin D supplementation in Chinese young children.
['Zhang|Heng|H|', 'Li|Zhijuan|Z|', 'Wei|Yarong|Y|', 'Fu|Jinyan|J|', 'Feng|Yaling|Y|', 'Chen|Daozhen|D|', 'Xu|Dexiang|D|']
D000367:Age Factors D044466:Asians D002648:Child D002675:Child, Preschool D002681:China D002947:Cities D019587:Dietary Supplements D004797:Enzyme-Linked Immunosorbent Assay D005260:Female D006801:Humans D007223:Infant D007231:Infant, Newborn D008297:Male D015995:Prevalence D012621:Seasons D011795:Surveys and Questionnaires D013696:Temperature D014807:Vitamin D D014808:Vitamin D Deficiency D014815:Vitamins
Vitamin D Children age Deficiency Air temperature Season