Objective To explore the effect of vitamin D preparation combined with lifestyle intervention on children with simple obesity.Methods Fifty children with simple obesity admitted to the Department of Child Growth and Development of Zhangzhou Hospital in Fujian Province from January 2018 to December 2023 were selected,and were divided into the control group and the observation group with 25 cases in each group according to a random number table.The control group was given simple lifestyle intervention,and the observation group was treated with vitamin D preparation intervention on the basis of the control group.The differences of body mass,blood glucose,and blood lipids before and after intervention were evaluated.Results There was no significant difference in body mass index between the two groups before intervention(P>0.05),but the body mass index in the observation group was lower than that in the control group after intervention(P<0.05).Before intervention,there was no statistical significance in blood glucose between the two groups(P>0.05),and after intervention,the blood glucose index of the observation group was lower than that of the control group(P<0.05).Before intervention,there was no statistical significance in blood lipid data between the two groups(P>0.05).After intervention,TG and TC indexes in the observation group were lower than those in the control group,with statistical significance(P<0.05).Conclusion Based on lifestyle adjustment,combining vitamin D preparation can improve obesity and glycolipid abnormality in children with simple obesity.