Iron absorption from food and dietary reference values
What it found
How much iron the body takes in from food varies widely, from about 14 to 18 percent on mixed diets to 5 to 12 percent on vegetarian diets in people with no iron stores.
Iron status matters more than diet composition.
What they found
Studies in people
How much iron is taken in
From intake data and isotope studies, the amount of iron taken in from food is estimated at 14 to 18 percent for mixed diets and 5 to 12 percent for vegetarian diets in people with no iron stores.
Diet factors in single meals
Phytate, polyphenols, calcium, ascorbic acid, and muscle tissue have repeatedly been shown to affect iron absorption in single-meal isotope studies.
Diet factors in varied diets
In multimeal studies with a varied diet and many inhibitors and enhancers, the effect of any single component is more modest, as expected.
Iron status and obesity
A person's iron status and other host factors such as obesity play a key role in how much iron is taken in, and iron status generally has a greater effect than diet composition.
Other findings
Fortification and additives
The importance of fortification iron and food additives such as erythorbic acid on how much iron is taken in from a mixed diet needs clarification.
Unresolved diet factors
The influence of vitamin A, carotenoids, and nondigestible carbohydrates on iron absorption and the nature of the meat factor remain unresolved.
What the authors conclude
“The iron status of the individual and other host factors, such as obesity, play a key role in iron bioavailability, and iron status generally has a greater effect than diet composition.”
Also in their conclusions
- They say it would be timely to develop a range of iron absorption factors based not only on diet composition but also on subject characteristics, such as iron status and prevalence of obesity.
How it was done
Iron is different from other minerals because the body controls it only by absorption, since there is no body process for getting rid of it. The authors wanted to review how well iron is taken in from food and how that is used to set dietary reference values.
They looked at intake data and isotope studies to estimate how much iron the body takes in from different diets. They also reviewed single-meal and multimeal studies on dietary factors that affect iron absorption.
What it can’t tell you
- We summarised it from the abstract only.
- This paper pulls together findings from many different studies, so it cannot prove cause and effect for any single dietary factor.
- The estimates come from isotope studies and intake data, which show patterns but cannot predict exactly how much iron any one person will absorb.
Who paid
- Authors work at
- Institute of Food, Switzerland
The paper
- Title
- Iron bioavailability and dietary reference values
- Type
- Study
- Evidence
- Studies in people
- Summarised from
- Abstract only
- Cite
- Hurrell R, Egli I (2010). Iron bioavailability and dietary reference values. The American journal of clinical nutrition. doi:10.3945/ajcn.2010.28674FPubMed 20200263DOI
Summary written 26 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error