稳定性同位素评价南方膳食结构中铁的吸收率

评价南方膳食结构中铁的吸收率,为我国不同人群、不同膳食类型的铁吸收率提供参考资料。采用~(57)Fe-EDTA或~(57)FeSO4两种铁的稳定性同位素示踪方法,以稀土元素Dy作为排泄物的回收标记物,于现场进行人体代谢试验,受试者为健康成年男子和孕龄妇女各10名,分6次口服3.0mg的~(57)Fe稳定性同位素示踪剂及2.0mg的Dy,粪便监测法收集同位素排出粪样;用电感耦合等离子体质谱仪测定粪样~(57)Fe/~(56)Fe的比值,用原子吸收光谱法测定粪样总Fe,从而计算该人群膳食铁的吸收率。在南方膳食结构中,口服~(57)Fe-EDTA示踪剂,成年男子膳食铁的吸收率为7.34%,孕龄妇女的吸收率为6.92%;口服~(57)Fe-SO4示踪剂,成年男子膳食铁的吸收率为6.01%,孕龄妇女的吸收率为5.40%。本研究结果表明口服~(57)Fe-EDTA评价膳食铁吸收率虽有高于用~(57)FeSO4评价结果的趋势,但无显著性统计分析差异。中国南方城市膳食中铁的吸收率与2000年中国营养学会对我国居民膳食铁吸收率的估计水平大致相当。

Evaluation of the Iron(Fe) Absorption in the Dietary Pattern in the Southern Cities of China by Stable Isotope Method

The iron (Fe) absorption in the dietary pattern of the cities of South China was evaluated by enriched stable isotope ~(57) iron tracer method with ~(57)Fe-EDTA and ~(57)FeSO_4 as tracers and the rare earth element dysprosium (Dy) as the marker indicating the tracer recovery.Ten healthy men and 10 healthy women were recruited as subjects in-situ metabolic trial taking 3.0mg Fe tracer and 2.0mg Dy in six meals of the continuous 2days.Fecal samples were collected by fecal monitoring.The isotopic ratio of ~(57)Fe/~(56)Fe was measured by inductively coupled plasma mass spectrometry (ICP-MS) and the total Fe was detected by atomic absorption spectrometry (AAS).In the dietary pattern of South China,taking ~(57)Fe-EDTA as tracer,the iron absorption for the men and women were 7.34% and (6.92%,)respectively,while for ~(57)FeSO_4,6.01% and 5.40% were obtained.The iron absorption from ~(57)Fe-EDTA was likely higher than that from ~(57)FeSO_4,but having no statistic difference,and comparable with level evaluated by the nutrition society of China in 2000.