Systematic review and meta-analysis · The Cochrane database of systematic reviews · 2020Abstract onlyConflicts declared

Iron-fortified wheat flour and anaemia in people

What it found

In nine trials in people, wheat flour fortified with iron alone or with other vitamins and minerals made little or no difference to anaemia or iron deficiency.

The authors are unsure whether it raises haemoglobin.

What they found

Studies in people

Anaemia, iron alone

Wheat flour with added iron alone may have little or no effect on anaemia. The authors rate the evidence as low certainty.

Iron deficiency, iron alone

It probably makes little or no difference to iron deficiency. The authors rate this evidence as moderate certainty.

Haemoglobin, iron alone

The authors are uncertain whether wheat flour with added iron raises haemoglobin. The evidence is very low certainty.

Anaemia, with other nutrients

Wheat flour with added iron plus other vitamins and minerals may or may not reduce anaemia. It makes little or no difference to iron deficiency, and may or may not raise haemoglobin.

Side effects

None of the trials reported side effects such as constipation, nausea, vomiting, heartburn or diarrhoea. No trials reported side effects in children, except for risk of infection or inflammation.

Infection and inflammation

Adding iron alone probably makes little or no difference to infection or inflammation measured by C-reactive protein. The authors rate this evidence as moderate certainty.

What the authors conclude

“Eating food items containing wheat flour fortified with iron alone may have little or no effect on anaemia and probably makes little or no difference in iron deficiency.”
Field MS, Mithra P, Estevez D, Peña-Rosas JP, 2020

Also in their conclusions

  • They say eating food items containing wheat flour fortified with iron alone may have little or no effect on anaemia and probably makes little or no difference in iron deficiency.
  • They say they are uncertain whether wheat flour fortified with iron increases haemoglobin concentrations.
  • They say consuming food items prepared from wheat flour fortified with iron, in combination with other micronutrients, has little or no effect on anaemia, makes little or no difference to iron deficiency and may or may not improve haemoglobin concentrations.

How it was done

Anaemia means not enough red blood cells to carry oxygen around the body. Adding iron to wheat flour is seen as a useful way to reduce anaemia in populations.

They looked at nine randomised trials with 3166 people aged two and over in Bangladesh, Brazil, India, Kuwait, the Philippines, Sri Lanka and South Africa. The trials lasted 3 to 24 months and compared flour with added iron, alone or with other vitamins and minerals, against flour without added iron or without those other nutrients.

What it can’t tell you

  • We summarised it from the abstract only.
  • The trials measured anaemia, iron status and haemoglobin. They cannot show what happens for other health outcomes.
  • The authors rate much of the evidence as low or very low certainty, so the results may change with more research.

The paper

Title
Wheat flour fortification with iron for reducing anaemia and improving iron status in populations
Type
Systematic review and meta-analysisThe authors follow a set, published method to find every relevant study, then combine the numbers from them into one result.
Evidence
Studies in people
Summarised from
Abstract only
Cite
Field MS, Mithra P, Estevez D, Peña-Rosas JP (2020). Wheat flour fortification with iron for reducing anaemia and improving iron status in populations. The Cochrane database of systematic reviews. doi:10.1002/14651858.CD011302.pub2Free full textPubMed 32677706DOI

Summary written 26 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error