Study on the Situation of Growth and Development of Kindergarten Children and the Relationship between Vitamin D and Body Composition, Chengdu, Sichuan Province, China

Vitamin D plays a critical role in bone health, mineral metabolism, and overall well-being, including immune function and muscle strength. Its potential impact on body composition in children, particularly in relation to obesity and undernutrition, is an area of growing interest. However, existing literature presents inconsistent findings regarding the correlation between Vitamin D levels and body composition parameters in pediatric populations. The aim of this study was to explore the relationship between Vitamin D levels and body composition among kindergarten-aged children in Chengdu, Sichuan Province, China, providing insights that could contribute to health promotion strategies for this demographic.A cross-sectional study was conducted among children aged 3 to 6 years across 47 kindergartens in Chengdu. Participants were selected via stratified random sampling to ensure representativeness. Data collection took place during April to June to minimize seasonal effects on Vitamin D levels. Body composition was assessed using bio-electrical impedance analysis (BIA). Vitamin D status was determined through blood tests, and the distribution of Vitamin D levels by sex and age groups was analyzed. The study included 1239 children, with 75.54% having insufficient Vitamin D levels and 24.46% having sufficient levels. There was no statistically significant difference in Vitamin D status between sexes (χ ² =0.676, p=0.411) or age groups (χ ² =4.700, p=0.095). Correlation analysis revealed that BMI had a weak negative correlation with Vitamin D (−0.028, p=0.320) but no significant correlation with Vitamin A (−0.007, p=0.799). Similar results were observed for other body composition components. This study suggests that a majority of kindergarten children in Chengdu have insufficient Vitamin D levels, regardless of sex or age. While some correlations between Vitamin D levels and body composition were observed, they were weak and not clinically significant. Further research is needed to elucidate the complex interplay between Vitamin D, body composition, and other influencing factors in this age group. Our findings contribute to the ongoing debate about the role of Vitamin D in pediatric health and may guide future interventions aimed at improving Vitamin D status and overall body composition in children.