Iron absorption mainly occurs in the small intestine and many factors can affect the absorption of iron.
Firstly the body can alter the amount that is absorbed depending if you are in a state of iron deficiency or if your iron deposits are full.
The type of iron in the foods you consume also influences how easy it is absorbed. There are two different types of iron found in foods, haem iron and non-haem iron. Haem iron is found almost exclusively in meat. Non-haem iron is found in animal and plant foods. Haem iron is 2-6 more times available for absorption than non-haem iron.
Consuming iron in the diet along side other compounds can also affect the absorption:
- Polyphenols, which are compounds found in tea, coffee and red wine, have been shown to decrease the amount of non-haem iron we can absorb.
- Phytic acid, which is a compound found in beans, seeds, nuts and grains has also be found to inhibit iron absorption.
There are also foods which can increase iron absorption:
- Consuming haem and non-haem iron together can increase how much iron is absorbed.
- Vitamin C has been found to reduce the effects that phylates have on iron absorption. Therefore consuming vitamin C containing foods with iron containing foods can increase absorption.
SACN recommendations state that it is a balanced diet that will achieve adequate iron status instead of focusing on foods/drinks that may enhance or inhibit iron absorption.
So although different types of iron are absorbed differently, and this absorption can change depending on the bodies need and other foods you are consuming iron with, to achieve an adequate iron status the recommendation is to focus on having a balanced and varied diet.