儿童户外活动及体质指数与维生素D营养状况的关系研究

目的 了解江苏省0~6岁儿童维生素D(VitD)营养状况,探讨户外活动时间及体质指数与VitD水平的关系。方法 采用分层随机整群抽样的方法,抽取江苏省12个地区0~6岁健康儿童5 289名,常规体检,测量体重、身长/高,计算体质指数(BMI),检测血清25-羟维生素D[25(OH)D]浓度,并进行相关问卷调查。结果 1)江苏省0~6岁儿童血清25(OH)D平均水平为(66.59±30.27)nmol/L,以25-(OH)D<75 nmol/L作为VitD 缺乏和不足的标准^[1],VitD缺乏和不足者3 471例(65.6%);2岁以上儿童VitD水平[(61.65±27.57) nom/L]明显低于2岁以下婴幼儿[(70.25±32.55) nom/L]。2)在校正年龄、性别等影响因素后,多因素回归分析显示:户外活动时间、BMI与VitD水平相关,每日户外活动时间达4 h以上者VitD水平最佳,随BMI增加,VitD水平呈上升趋势(F=4.168,P<0.05);以BMI>P 97th为肥胖标准,本研究中肥胖儿童409例(7.73%),肥胖儿童血清VitD水平[(65.94±29.56)nmol/L]低于正常儿童[(66.65±30.34)nmol/L],但差异无统计学意义(t=0.454,P=0.650)。结论 江苏省儿童VitD营养状况处于相对缺乏状态,2周岁以上儿童VitD水平显著低于2岁以下儿童;足够的户外活动时间有利于维持较好的VitD营养状况;在未达到肥胖标准时,儿童BMI与VitD水平呈正相关。

Vitamin D status and its relationship to the time of outdoor activities and the body mass index in 0~6 years old children

Objective To evaluate the vitamin D (VitD) nutritional status,and to investigate the interaction of 25-hydroxy-vitamin D [25(OH)D] and outdoor activities time and the body mass index in 0~6 years old children. Methods Utilizing a stratified random cluster sampling design,a total of 5 289 healthy children aged 0~6 years old were recruited from 12 regions of Jiangsu province.Anthropometric indices:weight,height,VitD levels were estimated by ELISA,and the related questionnaire investigation was carried. Results 1)The means and standard deviations of serum 25-(OH)D levels was (66.59±30.27)nmol/L,65.6% had VitD deficiency,VitD overdose and poisoning cases were not found.The level of 25-(OH)D was significantly higher in 0~2 years old group.2)When children's age,gender and other variables were adjusted,outdoor activities time and the BMI were correlated with the serum 25-(OH)D levels (P<0.01),Daily time for outdoor activities up to 4 hours had best VitD level (F=11.45,P<0.05).The research objects receiving physical examination were screened by BMI(BMI>P 97th was the standard for obesity).In the study with 409 cases of obese children,the 25-(OH)D concentration increased with BMI(F=4.168,P<0.05).In addition,the serum 25-(OH)D levels in obesity and normal group were (65.94±29.56)nmol/L and (66.65±30.34) nmol/L,and this difference was not significant(t=0.454,P=0.650). Conclusions There is a high prevalence of VitD deficiency in 0 to 6 year olds in Jiangsu province,especially for children over 2 years of age.The average VitD levels among children more exposed to sunlight is sufficient.When it is not up to the obesity standard,there is a positive correlation between 25-(OH)D levels and BMI.