Heme Iron vs. Non-Heme Iron
- Non-heme iron comes from plant foods, heme iron comes from animal foods
- Heme iron can be absorbed more effciently by the body
- The body can better regulate absorption of non-heme iron, helping to protect against toxic effects
Factors which Affect Iron Absorption and Retention
- The most important factor is your existing iron level. A low iron level will increase absorption, while a high iron level will decrease absorption. In general, you absorb 10-15% of the iron from foods.2
- Meat proteins will increase the absorption of nonheme iron.2
- Vitamin C will increase the absorption of nonheme iron by as much as 85%.2,3
- Tannins, oxalates, polyphenols, and phytates found in tea and coffee can reduce the absorption of non-heme iron by up to 65%. Black tea reduces absorption more than green tea and coffee.2,3,4
- The following teas and beverages also inhibit iron absorption: Peppermint tea, cocoa, vervain, lime flower, chamomile, and most other herbal teas with polyphenols.4
- Calcium, polyphenols, and phytates found in legumes, whole grains, and chocolate can reduce absorption of nonheme iron.
- Some protein from soy products may inhibit nonheme iron absorption.2
- Calcium, milk, and antacids can inhibit absorption of iron supplements.5
- High fiber foods, such as whole grains, raw vegetables, and bran can inhibit absorption of iron supplements.5
- Foods or drinks with caffeine can inhibit absorption of iron supplements.5
High Risk Groups for an Iron Deficiency
- Menstruating Women - Due to blood loss during menstruation women of child bearing age are at risk of iron deficiency, the greater the blood loss the greater the risk.
- Individuals with Kidney Failure - People with kidney failure, and especially those on dialysis, are at high risk of iron deficiency anemia. This is due to an inability of the kidney to create adequate amounts of the hormone erythropoietin which is necessary for red blood cell creation, and therefore, retaining iron.
- Pregnant and lactating women - A developing fetus requires a high amount of iron, likewise, there is a high amount of iron lost through breast milk after birth.
- Older infants and toddlers
- People with low levels of Vitamin A - Vitamin A greatly helps move iron from storage in the body, without adequate amounts of vitamin A the body cannot regulate iron properly leading to an iron deficiency.
- People with gastrointestinal disorders - Diarrhea, ulcers, and other gastrointestinal disorders and diseases can lead to an inadequate iron absorption.
