Kastenmayer P, Davidsson L, Galan P, Cherouvrier F, Hercberg S, Hurrell R F
Nestlé Research Centre, Lausanne 26, Switzerland.
Br J Nutr. 1994 Mar;71(3):411-24. doi: 10.1079/bjn19940148.
A stable isotope technique has been developed which uses 57Fe and 58Fe as labels and which enables the simultaneous measurement of Fe absorption from two test meals in infants. The method was evaluated by measuring Fe absorption from a commercial whey-adjusted infant formula in nine healthy infants aged 13-25 weeks. Each infant was fed 210 ml formula, labelled with either 57Fe or 58Fe, on four consecutive mornings, in random order. The total Fe content in each feed was 2.5 mg Fe; either as 2.5 mg 57Fe, or 0.6 mg 58Fe plus 1.9 mg Fe with normal isotopic composition. Isotopic enrichment of Fe in erythrocytes was measured by thermal ionization mass spectrometry 14 d after the last administration, and Fe absorption was calculated based on isotope ratio shifts, total circulating Fe and intake of each isotope. Geometric mean absorption for the 57Fe and 58Fe labels was 6.72 and 6.58% respectively, and the absorption of the two isotopes was not significantly different (Student's paired t test). By this technique, paired comparisons of Fe absorption can be obtained and systematic studies of the influence of dietary factors on Fe absorption during infancy can be conducted.
已开发出一种稳定同位素技术，该技术使用57Fe和58Fe作为标记物，能够同时测量婴儿从两种测试餐中吸收的铁。通过测量9名年龄在13至25周的健康婴儿从市售乳清调整型婴儿配方奶粉中吸收的铁来评估该方法。每个婴儿在连续四个早晨随机喂食210毫升分别用57Fe或58Fe标记的配方奶粉。每次喂食中的总铁含量为2.5毫克铁；要么是2.5毫克57Fe，要么是0.6毫克58Fe加上1.9毫克具有正常同位素组成的铁。在最后一次给药14天后，通过热电离质谱法测量红细胞中铁的同位素富集，并根据同位素比率变化、总循环铁和每种同位素的摄入量计算铁吸收量。57Fe和58Fe标记物的几何平均吸收率分别为6.72%和6.58%，两种同位素的吸收率无显著差异（学生配对t检验）。通过该技术，可以获得铁吸收的配对比较，并可以对婴儿期饮食因素对铁吸收的影响进行系统研究。
