Abstract: Objective To analyze serum 25-dihydroxy vitamin D[25(OH)D] levels of children in high altitude area in summer and to enrich serum 25(OH)D database resources,to explore the ideal serum 25(OH)D levels for children in China. Methods Each child was selected to collect venous blood in August and September 2013.The subjects were 0.2~7.3 years old children lived in Zhongzhuang,Huangzhong and Guide in Qinghai county.Total was 230 case,mean of age was (4.3±1.9) years old,boys were 113,girls were 117.The serum 25(OH)D levels were assayed by ELISA. Results 1)The mean serum 25(OH)D levels in boys and girls were (57.31±16.47)nmol/L and (53.48±14.39)nmol/L,respectively,there was no significant difference(P>0.05).The mean serum 25(OH)D levels in infant and preschool were (58.08±19.17)nmol/L and (54.15±13.50)nmol/L,respectively.There was no significant difference(P>0.05).There was no relation between serum 25(OH)D levels and age (r=-0.093,P>0.05).2)The mean serum 25(OH)D levels in Zhongzhuang,Huangzhong and Guide were (49.74±13.72)nmol/L,(52.59±15.07n)mol/L and (61.54±15.10)nmol/L,respectively.The mean 25(OH)D level of Guide was higher than Zhongzhuang and Huangzhong with significant difference.There was no significant difference between Zhongzhuang and Huangzhong.3)It was no discrepancy in the orders of the serum 25(OH)D levels and the altitude.It was observed that the serum 25(OH)D level was increased by decreased latitude.The percentage of serum 25(OH)D levels less than 27.5nmol/L of children was 2.1%(5/230). Conclusions There is significant difference in altitude area in summer.Altitude and latitude could have influence on the serum 25(OH)D.Gender and age have no influence on the serum 25(OH)D.Most of children on 25(OH)D levels in Qinghai are higher than 27.5 nmol/L.

Key words: vitamin D, altitude, sunlight, children

摘要： 目的 了解夏季高海拔地区儿童血清25羟维生素D[25(OH)D]水平,以丰富我国儿童血清25(OH)D数据库资源,研究我国儿童的理想血清25(OH)D水平。方法 2013年夏季8月和9月,选择海拔不同的青海省西宁市中庄、湟中县、贵德县三个地区的0.2~7.3岁汉族儿童230名为研究对象,年龄为(4.3±1.9)岁,男113名,女117名。西宁市中庄68名,湟中县69名,贵德县93名。均为健康儿童,日常自由户外活动,未补充维生素D。按照年龄分布状况把全部研究对象分为婴儿组和幼儿组;同时进行地域分组。采用酶联免疫法测定血清25(OH)D。结果 1)男童和女童血清25(OH)D分别为(57.31±16.47)nmol/L和(53.48±14.39)nmol/L,差异无统计学意义(P>0.05)。婴幼儿和学龄前期儿童血清25(OH)D分别为(58.08±19.17)nmol/L和(54.15±13.50)nmol/L,差异无统计学意义(P>0.05)。血清25(OH)D水平与年龄无相关性(r=-0.093,P>0.05)。2)西宁市中庄、湟中县、贵德县三个海拔不同地区的血清25(OH)D分别为(49.74±13.72)nmol/L,(52.59±15.07)nmol/L和(61.54±15.10)nmol/L。血清25(OH)D西宁市中庄与湟中差异无统计学意义(P>0.05);中庄、湟中与贵德差异均有统计学意义(P<0.001)。3)血清25(OH)D水平高低并不与海拔呈现相一致的变化特征。然而伴随纬度降低,对应的该地区的血清25(OH)D均数水平增加。4)全部研究对象中,血清25(OH)D低于27.5 nmol/L所占比例2.1%(5/230)。结论 夏季高海拔地区儿童血清25(OH)D存在差异;海拔和纬度是影响儿童血清25(OH)D水平的因素;性别和年龄不是影响高海拔地区儿童血清25(OH)D水平的因素;夏季高海拔地区绝大部分儿童血清25(OH)D能达到27.5 nmol/L以上。

关键词: 维生素D, 高海拔, 阳光照射, 儿童