Mendoza C, Viteri F E, Lönnerdal B, Raboy V, Young K A, Brown K H
Institute of Nutrition of Central America and Panama, Guatemala City, Guatemala.
Am J Clin Nutr. 2001 Jan;73(1):80-5. doi: 10.1093/ajcn/73.1.80.
Reducing the phytate content in grains by genetic manipulation is a novel approach to increasing nonheme-iron absorption from mixed diets. Fractional iron absorption from a genetically modified strain of low-phytate maize (LPM) increased significantly, by 50%.
We assessed iron absorption from porridges prepared from the same LPM (lpa-1-1 mutant) and unmodified wild-type maize (WTM), both of which were fortified with either ferrous sulfate or sodium iron EDTA.
Porridges providing 3.4 mg Fe were fortified with either ferrous sulfate or sodium iron EDTA to provide an additional 1 mg Fe/serving. In 14 nonanemic women, iron absorption was measured as the amount of radioiron incorporated into red blood cells (extrinsic tag method) 12 d after consumption of the study diets.
No significant effect of phytate content on iron absorption was found when porridge was fortified with either sodium iron EDTA or ferrous sulfate. Fractional absorption of iron from WTM porridge fortified with sodium iron EDTA (5.73%) was 3.39 times greater than that from the same porridge fortified with ferrous sulfate (1.69%). Fractional absorption of iron from the sodium iron EDTA-fortified LPM porridge (5.40%) was 2.82 times greater than that from LPM porridge fortified with ferrous sulfate (1.91%) (P<0.0001 for both comparisons, repeated-measures analysis of variance). Thus, the previously identified benefit of LPM was no longer detectable when maize porridge was fortified with additional iron.
Iron was absorbed more efficiently when the fortificant was sodium iron EDTA rather than ferrous sulfate, regardless of the type of maize.
通过基因操作降低谷物中的植酸盐含量是一种增加混合饮食中非血红素铁吸收的新方法。来自转基因低植酸玉米（LPM）品系的铁吸收分数显著增加了50%。
我们评估了由相同的LPM（lpa - 1 - 1突变体）和未改良的野生型玉米（WTM）制成的粥中铁的吸收情况，这两种玉米均用硫酸亚铁或乙二胺四乙酸铁钠进行了强化。
提供3.4毫克铁的粥用硫酸亚铁或乙二胺四乙酸铁钠进行强化，以每份额外提供1毫克铁。在14名非贫血女性中，在食用研究饮食12天后，通过测量掺入红细胞中的放射性铁的量（外源性标记法）来测定铁的吸收情况。
当粥用乙二胺四乙酸铁钠或硫酸亚铁强化时，未发现植酸盐含量对铁吸收有显著影响。用乙二胺四乙酸铁钠强化的WTM粥中铁的吸收分数（5.73%）比用硫酸亚铁强化的同一粥中的铁吸收分数（1.69%）高3.39倍。用乙二胺四乙酸铁钠强化的LPM粥中铁的吸收分数（5.40%）比用硫酸亚铁强化的LPM粥中铁的吸收分数（1.91%）高2.82倍（两次比较的P<0.0001，重复测量方差分析）。因此，当玉米粥额外添加铁时，先前确定的LPM的益处不再可检测到。
无论玉米类型如何，当强化剂为乙二胺四乙酸铁钠而非硫酸亚铁时，铁的吸收更有效。
