Fortifying wheat flour with iron appears to have little effect on improving intake of the mineral, suggests a report in this month's European Journal of Nutrition.
Researchers at the National Public Health Institute in Helsinki, Finland carried out a study on a random sample of adults to find out what effect fortification of wheat flour during the mid-1970s to 1994 had on the national population.
The team selected a random sample of more than 400 adults aged 25-64 years, stratified for sex and 10-year age groups. Food consumption was measured with 24-hour recall and a 38-item food frequency questionnaires. Iron status was evaluated by haemoglobin (Hb) concentration and other measures, including serum ferritin levels in women.
The authors found that cereals and meat were the main dietary sources of iron but concluded that food consumption was poorly associated with iron status.
Mean Hb concentration was lower in women under 50 years old than older women and men. Also, 20 per cent of younger women showed iron depletion compared to 11 per cent of older women. The prevalence of anaemia was 5.8 per cent for women and 1.3 per cent for men, with a mean intake of 10 mg daily and 13 mg per day respectively.
"While iron status is fairly good among Finnish males, in younger women especially it is suboptimal, with iron intake failing to reach recommended levels," noted the authors.
Iron in meat is more readily taken up into the body than iron from most other sources because it is mainly present as the more available haem iron, and because meat contains an as-yet-unidentified factor that enhances the uptake of not only meat iron, but also other iron in the same meal, recent research has found.
No data on iron status among adults in Finland had been published since 1993.
A European project, called 'Femmes', is currently investigating the effects of iron supplementation, on parameters such as oxidative stress and zinc and copper metabolism, in pregnant women.
The study is published in the October 2003 issue of the EJN, pp 287 - 292.