Systematic review and meta-analysis of the effect of iron-fortified flour on iron status of populations worldwide.

OBJECTIVE

Assess the effectiveness of iron-fortified flour on iron status.

DESIGN

Systematic review and meta-analysis.

SETTING

Argentina, Australia, Azerbaijan, Bangladesh, Brazil, Cameroon, Chile, China, Costa Rica, Côte d'Ivoire, Denmark, India, Iran, Jordan, Kazakhstan, Kenya, Kuwait, Mongolia, Morocco, Norway, South Africa, Sri Lanka, Tajikistan, Thailand, UK, USA, Uzbekistan, Venezuela, Vietnam, and Zambia.

PARTICIPANTS

Fifty-two articles (ninety-four trials) were examined. The main target groups were women, children, and infants/toddlers. The effects of different types of iron-fortified flour (wheat, maize, rice, soy, and beans) on iron status were examined.

RESULTS

A random effects analysis of before-after studies showed that iron-fortified flour led to significant increases of mean haemoglobin level (3·360 g/l; 95 % CI: 0·980, 5·730) and mean serum ferritin level (4·518 µg/l; 95 % CI: 2·367, 6·669); significant decreases of anaemia (-6·7 %; 95 % CI: -9·8 %, -3·6 %) and iron deficiency (ID) (-10·4 %; 95 % CI: -14·3 %, -6·5 %); but had no significant effect on iron deficiency anaemia (IDA). A random effects analysis of controlled trials indicated that iron-fortified flour led to significant increases of mean haemoglobin level (2·630 g/l; 95 % CI: 1·310, 3·950) and mean ferritin level (8·544 µg/l; 95 % CI: 6·767, 10·320); and significant decreases of anaemia (-8·1 %; 95 % CI: -11·7 %, -4·4 %), ID (-12·0 %; 95 % CI: -18·9 %, -5·1 %), and IDA (-20·9 %; 95 % CI: -38·4 %, -3·4 %).

CONCLUSIONS

Flour fortification with iron is an effective public health strategy that improves iron status of populations worldwide.