Food Frontiers Blog

Conference Update on Micronutrient Bioavailability

by PepsiCo

Several weeks ago, I attended UC Davis’s Bioavailability conference in Pacific Grove, CA where researchers from around the world presented on numerous topics relating to micronutrient bioavailability that revealed exciting new research underway.

Iron was a centerpiece of many discussions because it is the most common micronutrient deficiency worldwide, technically challenging to fortify, and complex interactions control its bioavailability.

Various mechanisms in the body regulate iron homeostasis by sensing dietary iron content, iron storage levels, and erythropoietic iron requirements and then adjust iron absorption and transport accordingly (Sharp P., Srai SK. World J Gastroenterol 2007;13(35):4716-4724). In the lumen, specific iron transporters and/or dietary factors help reduce ferric iron to ferrous iron for absorption into the cell system, while others are responsible for duodenal iron transport and homeostasis. Day-to-day variability in iron absorption is governed by the presence of iron “enhancers” and/or “inhibitors” in the diet. Numerous enhancers exist including ascorbic acid, citric acid and other small organic acids, “meat factors” and certain amino acids. Phytates and polyphenols are two of the most strongly inhibitory factors present in cereal products and tea, but other iron inhibitors may include calcium, phosphates, oxalates and egg protein. Diet factors may also influence gene expression of iron transporters. For example, the dietary polyphenol (-) -epigallocatechin-3-gallate (EGCG) is a strong inhibitor of iron transport in Caco-2 cells (Kim, Eun-Young, Ham, Soo-Kyung, Shigenaga, Mark K., Han, Okhee. J. Nutr. 2008 138: 1647-1651). Iron homeostasis is also controlled by various systemic regulators and of these hepcidin is the key regulator of iron metabolism.

The research underway to better understand these mechanisms and how they interact with dietary factors, inflammatory states (including obesity) and genetic polymorphisms may lead to future advances in nutrient bioavailability. These issues are important to PepsiCo because we have committed to providing consumers with innovative, highly nutritious food products. We look forward to future dialogue and potential collaboration with researchers involved in nutrient bioavailability research as a means of helping improving nutrition in developing and developed countries.

Tags: bioavailability, iron, micronutrients

Iron Supplements

Iron supplement helps to deliver oxygen to your muscles. Remember to keep all iron supplements away from children as an overdose could be avoid.
Ambronse Vik

That's true that iron helps to deliver oxygen to our body , but we also no forgot that most of iron supplements cause constipation, so must have those which are stomach friendly specially liquid iron supplements that contain vitamin C for better absorption .
John

This may be relevant to the developing world, but in the West we receive far too much dietary iron from all the red meat, fortified wheat, etc.

US hemochromatosis rates have gone up alarmingly over the last 30 years, and I suspect iron is the next salt in terms of 90% of Americans getting too much of it.
LisaFleige

Thank you for your comments. You raise some interesting points which I've tried to address below. I've also included a couple of links related to the subject that you may find helpful.

You are correct that iron deficiency is the most common nutrient deficiency worldwide and is a major problem in developing countries. Developing countries are a major focus of the research on iron bioavailability, because many people in these countries consume predominantly cereal-based diets that contain inhibitors of iron absorption resulting in iron deficiency. However, there are also subsets of people in developed countries that are deficient in iron. The recently published Dietary Guidelines for Americans (http://www.cnpp.usda.gov/DGAs2... states that "Substantial numbers of adolescent girls and women of reproductive capacity have laboratory evidence of iron deficiency." And that "Efforts are warranted to increase dietary intake of heme-iron-rich foods and of enhancers of iron absorption by these special populations, and increased intakes of lean, heme-iron-rich meat, poultry, and fish by adult women and adolescent girls."

People with hemochromatosis have a genetic predisposition to absorb iron very efficiently which may cause iron overload. Since hemochromatosis is often not diagnosed people who normally have adequate iron intake, e.g. adult men and postmenopausal women, should be cautious about taking iron supplements as well as other individuals with certain conditions. I'm not aware of any research suggesting that “US hemochromatosis rates have gone up alarmingly over the last 30 years", but did find this older article that states that "dietary iron supplementation begun in 1940 has not accelerated manifestations of hemochromatosis”( http://www.ncbi.nlm.nih.gov/pu.... Feel free to forward any more recent published cites that support your point!

There is some controversy surrounding iron and heart disease risk that may be of interest to you: http://ods.od.nih.gov/factshee....

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Conference Update on Micronutrient Bioavailability

by PepsiCo

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