Abstract Vitamin D (Vit D) deficiency is prevalent worldwide, and the prevalence of childhood obesity is increasing globally. Many studies have supported that Vit D deficiency may be an important cause of childhood obesity, and the level of serum Vit D among obese children decreases,simultaneously. Both Vit D deficiency and obesity among children interact through direct factors, molecular mechanisms and environmental factors, but the mechanism of interaction has not been fully elucidated. In the future, higher level research in evidence based medicine could be conducted to explore the association between childhood obesity and Vit D deficiency and the possible mechanisms of their interaction, in order to provide scientific evidence for the prevention and control of Vit D deficiency and obesity among children.

Objective: To understand the prevalence of elevated blood pressure and its association with dietary patterns in children and adolescents in China, providing evidence for developing dietary intervention of hypertension in children and adolescents. Methods: Data were derived from the China Children s Nutrition and Health System Survey and Application Project(2019-2021). A stratified cluster random sampling method was used to include 7 933 participants from 28 survey sites in seven major regions of Northeast, North, Northwest, East, Central, South and Southwest China. Multivariate Logistic regression models were used to analyze associations between demographic characteristics, nutritional status and elevated blood pressure. Exploratory factor analysis identified dietary patterns, which were divided into three quartile groups (T3, T2, T1) based on factor scores (compliance for dietary pattern) from high to low, and multivariate Logistic regression model assessed the correlation between elevated blood pressure and dietary patterns. Results: The prevalence of elevated blood pressure was 15.4% among Chinese children aged 7-17 years. Significant differences were observed across nutritional status (reference: underweight; normal weight: OR =1.57; overweight: OR = 2.61 ; obesity: OR =3.85), urban/rural residence (reference: rural; urban: OR =0.86), and paternal education (reference: junior high school and below; bachelor degree or above: OR =0.68) ( P <0.05). The detection rates of high blood pressure in T3 group children and adolescents with four dietary patterns (staple food, animal based food, snacks, vegetables and fruits) were 15.7%, 14.6%, 16.8%, and 15.8%, respectively. After adjusting for residence, paternal education, and nutritional status, the "snack dietary pattern" (mainly candy, sugar sweetened beverages, and processed snacks) showed positive associations with elevated blood pressure in T2 ( OR =1.21) and T3 ( OR =1.19) tertiles ( P <0.05). Conclusions The snack dietary pattern is a related factor for elevated blood pressure in children and adolescents. Restricting unhealthy snack intake may promote cardiovascular health.