Nutrients and health: continuing the series, this article looks at iron deficiency, one of the more important health problems in nutrition.
Iron deficiency, which in humans is commonly referred to as anaemia, is the most prevalent micronutrient deficiency. It affects 1.2 billion people or 20% of the world's population.
Although we obtain about a third of our iron requirements from so-called "haem iron," which is found only in meat and fish, the majority is acquired from "non-haem" sources, predominantly cereals and vegetables. The main problem with "non-haem iron" is that, unlike "haem iron", it is very poorly absorbed by the human body. Many dietary components inhibit its uptake - such as phytic acid (a component of dietary fibre), oxalic acid (a compound found in some vegetables) and minerals (such as calcium). Only a few nutrients enhance its absorption; one of the most effective is vitamin C. When food is fortified with iron it is the "non-haem" form which is added.
Overcoming anaemia is not simply a matter of adding iron to food: this can have distinct disadvantages, both for the consumer, through iron overload/toxicity or an unacceptable taste, and for the food product itself, e.g. rancidity of fats. Food manufacturers should bear in mind that it is better to ensure that the iron source used to fortify foods is normally well absorbed, and that nutrients that inhibit iron absorption are minimised, while those that enhance it are maximised. Consumers should thus check their diet for a good balance of "haem" and "non-haem" iron.
Prevalence of Iron Deficiency
Estimated Percentage of Anaemia
| ||Infants ||Children ||Women |
|0-4 Yrs ||5-12 Yrs ||15-49 Yrs |
|World ||43 ||37 ||35 |
|South Asia ||56 ||50 ||58 |
|Africa ||56 ||49 ||44 |
|Latin America ||26 ||26 ||17 |
|Industrial countries ||12 ||7 ||11 |