China's 7-year-old Children Vitamin B, <sub> 12 </ Sub> Nutritional Epidemiology Survey

PARTⅠVITAMIN B12 NUTRITIONAL STATUS IN CHILDREN AGED 2～7 IN CHINA【objective】To explore the levels of serum vitamin B12 (VB12)of preschool children in 4 cities of China;determine the relationship between the levels of serum VB12 and anemia and analyze the effects of several factors related to the level of serum VB12.;To explore the sensitive and specific markers of VB12 deficiency;investigate the level of intellectual functioning in the children with VB12 deficiency;【Methods】From May 2007 to October 2008,the weight,height and complete blood count(CBC)were studied in 2116 children aged 2 to 7 years from the four cities(Bejing,Zhuhai,Chongqing,wuhan) in China.The dietary survey,the concentrations of serum VB12 of 2002 of the children were evaluated. The concentrations of serum VB12 were assayed by Chemiluminoimmuno Assay(CLIA). Plasma total homocysteine was determined by using HPLC with fluorescence detection.Psychological tests were performed in the children with VB12 deficiency by Gesell Developmental Schedules(GDS)or Wechsler Preschool and Primary Scale of Intelligence(WPPSI). 【Results】1,The average level of serum VB12 for the children aged 2～7 in China was 775pg/ml,and the level of serum VB12 for the children aged 2～7 in urbans was higher than that in suburbs(P<0.001). The concentrations of serum VB12 of children in Beijing,Zhuhai,Chongqing,Wuhan were 840pg/ml,772 pg/ml,756 pg/ml and 735pg/ml,respectively. 2,The levels of serum VB12 changed with ages and there were no differences between the concentrations of both boys and girls .3,1.5% of the preschool children who were assessed for VB12 levels<200pg/ml were considered the vitamin B12 deficiency,3.2% were considered the vitamin B12 marginal deficiency.The prevalence of low VB12 ( deficiency and marginal deficiency)of children in urbans was lower than that in suburbs.The prevalence of low VB12 of children in Beijing,Zhuhai,Chongqing,wuhan were 0.4% and 3.5%,0.2% and 3.0%,0.2% and 1.9%,5.2% and 4.6%,respectively. There were differences of the prevalence of lowVB12 among the cities. 4,There were low correlations between the levels of serum VBl2 and hemoglobin(P<0.001).The average level of hemoglobin for the children aged 2～7 in China was 125.1 g/L,the average levels of hemoglobin in Beijing zhuhai,chongqing,wuhan were 129.2 g/L(the level of hemoglobin130.4 g/L in urban is higher than that in suburb 128.1g/L),127.4 g/L(the level of hemoglobin129.5g/L in urban is higher than that in suburb125.2 g/L),123.5 g/L(the level of hemoglobin125.4g/L in urban is higher than that in suburb121.7 g/L),120.3 g/L(the level of hemoglobin121.3g/L in urban is higher than that in suburb119.3 g/L)。5,Negative correlations were found between VB12 and tHcy(r=-0.445,P=0.000). The serum tHcy concentration in children with adequate VB12 concentration was lower than that in children with VB12 deficiency(F=51.391,P=0.000). 6,The mean scores of DQ were 104,94,90,96 for 9 children with low VB12;The mean scores of VIQ,PIQ,FIQ were 98,94,103 for 57 children with low VB12 .The data analysized by Wilcoxon test showed that there were no significant differences between the children with lowVB12(deficiency and marginal deficiency)and adequate serum VB12 in intelligent tests.7,The results of multivariate stepwise influenced by the contents of VB12 in the animal foods(bˊ=0.116,P=0.000).The contents of VB12 in animal foods children aged 2～7in urbans were higher than that in suburbs(P<0.05).And the contents of VB12 in animal foods for children in the 4 cities were different(P<0.001).【conclusions】1,Low serum VB12 of children aged 2～7 was prevalent in China.2,The levels of serum VB12 of children aged 2～7 were higher than that of adults.3,The levels of serum VB12 were lowly correlated with the concentrations of hemoglobin.Macrocytic anemia may not occur in children with VB12 deficiency and small or normal cell anemia can be investigated in the early stage of VB12 deficiency.4,The concentrationof serum tHcy exhibited negative correlations with the levels of serumVB12,respectively and may be regarded as a basic marker of VB12 in the serum.5, The children with VB12 deficiency may not occur cognitive impairment.6,The nutritional condition of vitamin B12 was different by the diets of the children,it is beneficial for children to consume foods with VB12 to keep the normal level of serum VB12. PARTⅡORAL VB12 THERAPIES IN CHILDREN WITH VB12 DEFICIENCY【objective】To investigate the effect of therapy with oral vitamin B12(VB12)on the children with VB12 deficiency,explore the effective and safe way to treat and prevent VB12 deficiency in children. To discuss the effect of VB12 supplementation on the cognitive function of children with VB12 deficiency .【Methods】70 children with VB12 deficiency were received VB12 100μg/d for 4 weeks. The levels of serum VB12 and the intellectual function were redetected in 34 children.【Results】The levels of serum VB12 in 70 children were increased after supplementation of VB12 .The mean level of serum VB12 in 70 children was increased from 825pg/ml to 596pg/ml after one month of oral supplementation(t=-22.2,P<0.01).【conclusions】Oral supplementation of VB12 for the children with VB12 deficiency improve the nutritional condition of VB12. The data showed IQ were same in children of 2~3 years old with VB12 deficiency but that were increased in the children aged 4~7.