补充维生素A与铁对改善学龄前儿童贫血和免疫功能的影响

目的为观察学龄前儿童亚临床维生素A(VA)缺乏状态缺铁时,机体免疫功能的变化以及VA与铁同时补充对改善儿童铁营养状况和免疫功能的影响.方法检测北京农村270名3～7岁儿童血清VA含量和血红蛋白(Hb)、血清铁(SI)、运铁蛋白饱和度(TS)及血清铁蛋白(SF)后,将其分为正常、低 VA、低铁和低VA低铁4组,每组选40人,检测血清免疫球蛋白IgA、IgG、IgM 与白细胞介素-2(IL-2).然后将低VA低铁组儿童随机分为补铁组 (每日口服相当于30 mg元素铁的硫酸亚铁,连续8周)和补VA+铁组(口服VA胶丸12 500 IU /次,2次/周,连续8周;口服铁量同补铁组,连续8周),分别进行干预.干预后重复检测血清VA、血液铁生化指标和以上免疫指标,进行两组间比较,并与干预前比较. 结果低VA低铁组儿童血清IgM为(1 260±310) mg/L显著高于正常组的(1 0 7 0±170) mg/L.对其实施VA+铁联合干预后,血清TS为(26.5±8.6)%,明显高于补铁前的(16.2±1.6)%和单纯补铁组的(22.3±3.8)%;IL-2在VA与铁同时补充后为(2 78.9±117.7) ng/L,显著高于补充前的(161.6±90.3) ng/L和单纯补铁组的(189 .5 ±89.3)ng/L的水平;其他铁生化指标和免疫指标无明显变化.结论对存在亚临床VA缺乏状态的缺铁儿童实施一定剂量的VA+铁联合干预,对改善机体铁营养状况和免疫功能有明显作用.

Effects of vitamin A and iron supplementation on the improvement of iron status and immunological function in preschool children

OBJECTIVE: In order to understand the changes in immunological function in rural preschool children with lower levels of vitamin A and iron, and the effect of vitamin A and iron supplementation on the improvement of iron status and immunological function. METHODS: Serum vitamin A concentration and hemoglobin (Hb), serum iron (SI), transferrin saturation (TS), serum ferritin (SF) were determined in 270 rural preschool children aged 3-7 years in Beijing, and the subjects were divided into four groups based on their determinations: control, lower serum vitamin A, lower iron, and both lower iron and serum vitamin A. Forty subjects were selected from each group, and serum IgA, IgG, IgM and interleukin-2 (IL-2) were determined for them. Forty-one subjects who had lower iron and lower serum vitamin A (< 1.12 mumol/L) were divided into two groups: one of them supplemented with 30 mg iron element (ferrous sulfate 0.15 g) once a day for 8 weeks, and the other group supplemented with iron and 12,500 IU vitamin A twice a week for 8 weeks. After supplementation of vitamin A and iron, their serum vitamin A, hematological iron index and serum immunological index were determined again for the two groups. RESULTS: Serum IgM were (1,260 +/- 310) mg/L in both lower iron and serum vitamin A groups, significantly higher than that in normal group (1,070 +/- 170) mg/L (P < 0.05). But there were no significant differences in serum levels of IgG, IgA and IL-2. After supplementation of iron and vitamin A, their serum TS increased to (26.5 +/- 8.6)%, significantly higher than that before supplementation and that supplemented with iron only (22.3 +/- 3.8)%. And, their serum IL-2 were (278.9 +/- 117.7) ng/L after supplementation, significantly higher than that before supplementation (161.6 +/- 90.3) ng/L and that in those supplemented with iron only (189.5 +/- 89.3) ng/L. There was no significant difference in other biochemical indices of iron and immunological indices. CONCLUSIONS: Supplementation with vitamin A and iron was helpful to improve body iron nutritional status and immunological function obviously in preschool children with iron-deficiency and sub-clinical deficiency of vitamin A.