Iron absorption from the whole diet in men: How effective is the regulation of iron absorption
Iron absorption from the whole diet in men: How effective is the regulation of iron absorption
复制标题
DOI：
10.1093/ajcn/66.2.347
复制
发表时间：
1997-08-01
影响因子：
7.1
通讯作者：
Gramatkovski, E
中科院分区：
文献类型：
--
作者：
Hallberg, L;Hulten, L;Gramatkovski, E
在31名健康男性（包括12名献血者）中测定了5天的全饮食（其中含有高生物利用度形式的铁）中的铁吸收。所有膳食中的非血红素铁标记有外源性无机放射性铁示踪剂，其添加量确保所有膳食中的均匀比活度。血红素铁的标记类似地使用血红蛋白生物合成标记与另一种放射性铁示踪剂。总吸收与血清铁蛋白浓度之间存在良好的负相关关系，直至接近60 μ g/L。在血清铁蛋白> 60 μ g/L的受试者中，与铁吸收无关。在此血清铁蛋白浓度下，吸收降低到刚好足以覆盖基础铁损失的水平，这意味着在血清铁蛋白浓度大于或等于60 μ g/L时，通过膳食铁吸收不会发生铁储存的进一步积累。因此，研究结果表明，在正常受试者中，即使饮食强化，从饮食中吸收铁也没有发生铁过载的风险。之前在两项针对女性的研究中也有类似的发现，这两项研究都表明有效控制了吸收。在相同的血清铁蛋白浓度下，每公斤体重的吸收量在男性和女性中是相同的，具有高的铁生物利用度。这些新的观察结果强烈表明，血清铁蛋白浓度转化为储存铁的量应谨慎进行，并在高血清铁蛋白浓度的受试者，应考虑其他原因而不是增加铁储备。血红素铁和非血红素铁的吸收都得到了有效的控制，但它们与铁营养状况的关系是不同的。
Iron absorption from the whole diet, which contained a highly bioavailable form of iron, was measured for 5 d in 31 healthy men, including 12 blood donors. Nonheme iron in all meals was labeled with an extrinsic, inorganic radioiron tracer added in amounts to ensure uniform Specific activity in all meals. Heme iron was labeled similarly by using hemoglobin biosynthetically labeled with another radioiron tracer. There was a good inverse relation between total absorption and concentration of serum ferritin up to approximate to 60 mu g/L. In subjects with serum ferritin > 60 mu g/L there was no relation to iron absorption. At this serum ferritin concentration, absorption decreased to a level just sufficient to cover basal iron losses, implying that at a serum ferritin concentration greater than or equal to 60 mu g/L no further accumulation of iron stores will occur by dietary iron absorption. The findings thus suggest that in normal subjects there is no risk of developing iron overload by iron absorption from the diet even if the diet is fortified. Similar findings were made previously in two studies in women, both of which indicated an effective control of absorption. At the same serum ferritin concentration the absorption per kilogram body weight was the same in men and women served identical diets with a high iron bioavailability. These new observations strongly suggest that translation of serum ferritin concentration into amounts of stored iron should be made with caution and that in subjects with high serum ferritin concentrations, other causes than increased iron stores should be considered. There was effective control of both heme- and nonheme-iron absorption but their relations to iron status were different.