6.5 The spectrum of iron nutritional statusIn normal individuals, the iron used for haemoglobin formation accounts forabout two-thirds of total body iron. In men, about one-third of body iron maybe deposited as haemosiderin or ferritin in stores that can be mobilized whenthere occurs a need to supply iron in a functionally active form.About 14% of iron is used for other vital physiological functions (80).In addition, a small pool of iron in plasma is in transit, and bound to the ironcarrier transferrin(81).Measurements of haemoglobin, serum ferritin, serum iron, and transferrin(total iron-binding capacity) enable iron status to be characterized in detail(82).However, each of these determinations has well-recognized limitationsunder field conditions, i.e. single or combined measurements of iron statusshow that response to therapeutic trials is greater than expected.As previously noted, iron deficiency anaemia represents the extreme low endof the spectrum of iron status. The severity of anaemia is differentiated by theseverity of the reduction in haemoglobin level.The term “anaemia” is sometimes used synonymously with “iron deficiencyanaemia”. Clearly, however, these terms do not cover the same reality. Thereare about 2-5 times more iron-deficient than iron-deficient-anaemic individuals.There are also many causes of anaemia besides iron deficiency, particularlyin tropical regions.In any case, however, iron deficiency is the predominant nutritional deficiencycausing anaemia and is present even when other causes of anaemia arerecognized. There are, however, mild-to-moderate forms of iron deficiencyin which anaemia is absent.
đang được dịch, vui lòng đợi..