Jaramillo Ángela, Briones Lautaro, Andrews Mónica, Arredondo Miguel, Olivares Manuel, Brito Alex, Pizarro Fernando
Micronutrient Laboratory, Institute of Nutrition and Food Technology, University of Chile, Santiago, Chile.
Micronutrient Laboratory, Institute of Nutrition and Food Technology, University of Chile, Santiago, Chile; United States Department of Agriculture, Western Human Nutrition Research Center, University of California, Davis, USA.
J Trace Elem Med Biol. 2015 Apr;30:112-7. doi: 10.1016/j.jtemb.2014.11.005. Epub 2014 Nov 27.
To determine the effect of phytic acid, tannic acid and pectin on fasting non-heme iron bioavailability in both the presence and absence of calcium.
Twenty-eight apparently healthy adult females participated in two iron absorption studies using radioactive iron isotopes ((59)Fe and (55)Fe). One group received 5mg of iron (as FeSO4) alone (control), together with 10mg of phytic acid, 100mg of tannic acid and 250mg of pectin (study A), on different days. The second group received the same iron doses and compounds as the other group, plus 800mg of calcium (CaCl2) (study B). The compounds were administered after an overnight fast, and no food or beverages were consumed for the following 3h. Iron status and circulating radioactivity were measured in venous blood samples.
The geometric means of iron bioavailability (range±1SD) for iron alone, iron with phytic acid, iron with tannic acid, and iron with citrus pectin were 25.0% (11.9-52.0); 18.9% (9.9-35.8); 16.8% (8.7-32.3); and 21.1% (10.2-43.9), respectively (repeated-measures ANOVA, p<0.02 (Dunnett's post hoc: control vs tannic acid p<0.05). When 800mg of calcium was added (study B), iron bioavailability was 16.7% (10.1-27.5); 13.2% (7.1-24.6); 14.8% (8.8-25.1); and 12.6% (5.5-28.8), respectively (repeated-measures ANOVA, NS).
Tannic acid decreases the fasting bioavailability of non-heme iron, however this effect did not exist in the presence of calcium. No effect was observed by phytic acid or citrus pectin on fasting non-heme iron bioavailability in both the presence and absence of calcium.
确定植酸、单宁酸和果胶在有钙和无钙情况下对空腹非血红素铁生物利用度的影响。
28名表面健康的成年女性参与了两项使用放射性铁同位素（⁵⁹Fe和⁵⁵Fe）的铁吸收研究。一组在不同日期单独接受5毫克铁（以硫酸亚铁形式）（对照组），同时分别接受10毫克植酸、100毫克单宁酸和250毫克果胶（研究A）。第二组接受与另一组相同剂量的铁和化合物，外加800毫克钙（氯化钙）（研究B）。这些化合物在禁食过夜后给药，随后3小时内不进食或饮用任何饮料。在静脉血样本中测量铁状态和循环放射性。
单独铁、铁与植酸、铁与单宁酸以及铁与柑橘果胶的铁生物利用度几何平均值（范围±1标准差）分别为25.0%（11.9 - 52.0）；18.9%（9.9 - 35.8）；16.8%（8.7 - 32.3）；以及21.1%（10.2 - 43.9）（重复测量方差分析，p<0.02（Dunnett事后检验：对照组与单宁酸组p<0.05）。当添加800毫克钙时（研究B），铁生物利用度分别为16.7%（10.1 - 27.5）；13.2%（7.1 - 24.6）；14.8%（8.8 - 25.1）；以及12.6%（5.5 - 28.8）（重复测量方差分析，无显著性差异）。
单宁酸会降低空腹非血红素铁的生物利用度，但在有钙存在的情况下这种影响不存在。在有钙和无钙情况下，均未观察到植酸或柑橘果胶对空腹非血红素铁生物利用度有影响。
