Dietary Sources and Intakes of Iron

Abstract

The most important sources of iron are those foods which are not only rich in iron but also eaten in significant quantities, and from which iron is reasonably well absorbed (Chapter 2). The amounts of iron vary widely between foods, as indicated in Table 3.1. While milks (including human milk) and milk products, sugars and fats contain little, liver and shellfish which concentrate iron in their tissues are rich sources. However, the latter foods are not popular in Britain and the major sources in practice are the widely eaten cereal products, which provided nearly half the average household intake of iron in 1993 (Table 3.2). Meats and meat products provided a further 18% on average, but because about half of this is haem iron it would be better absorbed than the iron in cereals. Vegetables also provided about 16% on average of the total household iron intake. The intake provided 95% of the UK Reference Nutrient Intake (RNI), after allowance for meals not taken from the domestic food supply and for wastage of food within the home. The UK Dietary Reference Values (DRV5) are based on the assumption that a diverse diet (including meat, poultry, fish and reasonable amounts of vitamin C) is consumed and that iron absorption will be about 15%. Many dietary and physiological factors affect the bioavailability of iron (Chapter 2; DH, 1991) and may lower or raise the required intake. It is clear that the DRVs for iron must be interpreted with caution.