La absorción del hierro de los alimentos

Abstract

Studies on iron absorption from food when iron is incorporated biologically have shown that it varies considerably according to the type of food and individual tested; it even varies within the same individual in consecutive days. Iron from vegetable food, especially from spinach, corn, and black beans, is poorly absorbed, with a mean of less than 2 per cent in normal subjects. The only exception is soybean iron, the average absorption of which (11 per cent) is comparable to the range observed for foods of animal origin. The rate of iron absorption from each individual food correlated significantly with inorganic iron absorption, and not with either plasma iron or percentage of transferrin saturation. The ration of iron absorption versus inorganic iron absorption was less than 0.20 in the case of corn, black beans, and spinach; from 0.20 to 0.29 with wheat and lettuce; from 0.30 to 0.39 with soybean and hemoglobin; 0.52 with fish, and 0.97 with veal

The administration in one meal of animal and vegetable food tagged with different isotopes showed that iron absorption from animal food is only slightly decreased or not decreased at all. On the other hand, corn or black bean iron was absorbed twice or three time better when mixed with animal food than when administered alone. Further studies have shown that amino acids, especially those containing sulfur, enhance vegetable iron absorption in a...(AU)