Heme iron found in meats, fish and poultry are different than non-heme iron found in plant foods.
Vegetarians and vegans are consuming very little to no heme iron, respectively. A diet rich in legumes and whole grains can contain just as much iron as an omnivore's diet, however the forms of iron from these two sources are different in terms of bioavailability. The only source of iron for vegans is non-heme form, which needs to be converted to another form before it can be absorbed. This makes it less bioavailable then the heme form found in animal sources (Rogers, 2017).
In addition to lower absorption rates of iron, vegan diets are typically high in dietary inhibitors which can further reduce the amount of iron being absorbed.
Some of these inhibitors include:
◾ phytates, which are largely found in legumes and whole grain foods
◾ polyphenols, which are largely found in cocoa, coffee and teas
Studies have found some vegans to have lower iron stores than omnivores, however the body's ability to appropriately regulate iron makes adverse side effects from low iron consumption or absorption rare. The body has the ability to regulate iron by adapting its absorption rates. Our body has elaborate mechanisms that can control the amount of iron in circulation by sensing iron levels in the blood and adapting iron absorption and iron recycling as necessary to maintain iron homeostasis (Rogerson, 2017).
For vegetarians and vegans to optimize iron absorption they should eat iron rich foods in conjunction with vitamin C 🍈🍋🍊, as it enhances iron absorption.
To be sure they are getting these two nutrients together they should acquire their iron from whole food sources and refrain from eating foods containing iron inhibitors, such as phytates and polyphenols, when consuming iron rich meals (Rogerson, 2017).
The act of soaking, sprouting and fermenting breaks down phytates, making these foods a good option for vegetarians, vegans and even omnivores who are seeking to optimize iron absorption.
References
Rogerson, D. (2017). Vegan diets: practical advice for athletes and exercisers. Journal of the International Society of Sports Nutrition. Retrieved from https://jissn.biomedcentral.com/articles/10.1186/s12970-017-0192-9
Wallace D. F. (2016). The Regulation of Iron Absorption and Homeostasis. The Clinical biochemist. Reviews, 37(2), 51-62. Retrieved https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5198508/
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