Vitamin D status and its dietary and lifestyle factors in children during the first 5 years of life: A cross‐sectional multicentre Jiangsu bone study

Background To explore the vitamin D status with its demographic and lifestyle factors including dietary, supplementation, and physical activity in 0–5 years old children. Methods This was a large population‐based cross‐sectional multicentre study in which the children were recruited from 12 Children’s Health Care Centers by a stratified cluster random‐sampling method in 10 cities in Jiangsu Province, China. Results A total number of 5289 children were investigated. The prevalence of vitamin D deficiency was 30.1%. The concentration of 25 hydroxyvitamin D was 64.0 (46.3–83.0) nmol mL −1 after adjustment for covariates. Children with higher risk of vitamin D deficiency were more likely to be at older age, girls, survey conducted in spring, location in southern Jiangsu province, residence in urban, outdoor activity < 2 h day −1 (all p  < 0.05). Moreover, those with lower risk were more likely to be the number of parity ≥ 2 times, vitamin D supplementation from birth to 6 months, the initial time of vitamin D supplementation after birth ≤ 1 months, vitamin D and calcium supplementation in the last 3 months, and dose of vitamin D supplementation > 400 IU day −1 (all p  < 0.05). Children with preferences for sweets, meat consumption > 150.0 g day −1 , milk consumption < 250 mL day −1 , time of sleeping < 10 h day −1 had higher risks of vitamin D deficiency. However, these relationships were affected by demographics. Conclusions Vitamin D status during the first five years of life was suboptimal and was associated with demographic and lifestyle determinants including milk, meat, sweets, vitamin D and calcium supplementation, sleeping and outdoor activity.