【摘要】 目的了解4城市2～7岁分析人群维生素B12的营养状况。方法2007年5～9月和2008年5～10月,对2002名2～7岁分析人群进行体格检查、膳食调查、血常规检查及血清维生素B12水平测定,其中重庆市485名、北京市513名、珠海市503名、武汉市501名。结果①2002名2～7岁分析人群平均维生素B12水平(ng.L-1)为775±312,市区(835±271)高于郊区(720±338),P<0.001;其中重庆市为756±220、北京市为840±414、珠海市为772±245、武汉市为736±317,地区间差异有统计学意义,P<0.001。②2～7岁分析人群维生素B12水平性别差异不显著,P>0.05;2～5岁组维生素B12水平随年龄增长呈降低趋势,r=-0.146,P<0.001;5岁～组和<7岁组维生素B12水平相近。③4城市分析人群维生素B12减少(<300)检出率为4.7%。其中维生素B12缺乏(<200)检出率为1.5%,边缘性缺乏(200～300)检出率为3.2%。重庆市、北京市、珠海市和武汉市分析人群血清维生素B12减少检出率分别为2.1%、3.9%、3.2%和9.6%。④分析人群维生素B12水平主要受膳食维生素B12摄入量的影响,P<0.001。分析人群平均膳食维生素B12摄入量(μg.d-1)市区(2.4±2.0)高于郊区(2.0±1.4),P<0.05;重庆市、北市京、珠海市和武汉市分析人群平均膳食维生素B12摄入量分别为1.9±1.3、2.8±1.6、2.6±1.8和1.6±1.2,差异有显著统计学意义,P<0.001。⑤分析人群维生素B12水平与Hb水平呈低度相关,P<0.001。结论4城市分析人群存在维生素B12减少,以边缘性缺乏为主。儿童维生素B12营养状况受膳食维生素B12摄入量的影响,分析人群血清维生素B12水平何时达到成人水平有待研究。更多还原

【Abstract】 Objective To explore the serum vitamin B12 levels of children at the age of 2 to 7 years in 4 cities in China and to define the relationship between the levels of serum vitamin B12 and anemia and analyze the effects of several factors related to the level of serum vitamin B12.Methods From May to September 2007 and from May to October 2008,the weight,height and complete blood count(CBC)were measured in 2 116 children at the age of 2 to 7 years in four cities(Chongqing 562,Bejing 513,Zhuhai 560,Wuhan 501) in China.The dietary survey and the concentrations of serum vitamin B12 of 2 002 children were evaluated.The concentrations of serum vitamin B12 were assayed by chemiluminoimmuno assay(CLIA)and the CBC was detected by holo-automatic blood analyser.Results ①The average level of children serum vitamin B12(ng·L-1) was 775±312,and the level of children serum vitamin B12 in urbans was higher than that in suburbs(P<0.001).The concentrations of serum vitamin B12 of children in Chongqing,Beijing,Zhuhai and Wuhan were 756±220,840±414,772±245 and 736±317,respectively.②The prevalence of low vitamin B12(vitamin B12 level<300 ng·L-1)was 4.7%.1.5% children whose vitamin B12 level was assessed<200 ng·L-1 were considered as the vitamin B12 deficiency,3.2% children were considered as the vitamin B12 marginal deficiency(vitamin B12 level 200-300 ng·L-1).The prevalence of low vitamin B12(deficiency and marginal deficiency) in urbans children was lower than that in suburbs.The prevalence of low vitamin B12 of children in Chongqing,Beijing,Zhuhai and Wuhan was 2.1%,3.9%,3.2% and 9.6%,respectively.There were differences of the prevalence of low vitamin B12 among the cities.③There were differences of serum vitamin B12 in ages(P<0.001),and the levels of serum vitamin B12 changed with age from 5 to 7 years.But there were no differences between gender(P>0.05).④The results of multivariate stepwise indicated that the concentrations of serum vitamin B12 were mainly related to the contents of vitamin B12 in animal foods(P<0.05)(b’=0.116,P=0.000).The contents of vitamin B12 in animal foods for children at the age of 2 to 7 years in urbans were higher than those in suburbs(P<0.05).And the contents of vitamin B12 in animal foods for children in the 4 cities were different(P<0.001).⑤ There were low correlations between the levels of serum vitamin B12 and hemoglobin(P<0.001).The average level of hemoglobin(g·L-1) for the children aged 2 to 7 years in China was 125±11,the levels of hemoglobin in Chongqing,Beijing,Zhuhai and Wuhan were 124±13,129±8,127±13 and 120±9.The level of hemoglobin in urban was higher than that in suburbs.Conclusions Low serum vitamin B12 of children aged 2 to 7 years was popular in China.But the level of serum vitamin B12 in children aged 2 to 7 years was higher than that in adults.The nutritional condition of vitamin B12 was different by the diets of the children,the contents of vitamin B12 in animal foods determined the levels of serum vitamin B12 for the children and it was beneficial for children to consume foods with vitamin B12 to keep the normal level of serum vitamin B12.The levels of serum vitamin B12 were lowly correlated with the concentrations of hemoglobin.Macrocytic anemia may not occur in children with vitamin B12 deficiency and small or normal cell anemia could be investigated in the early stage of vitamin B12 deficiency.There was no markedly diference in the level of serum vitamin B12 of children between gender,and the level of serum vitamin B12 of children changed with ages.更多还原