Vitamins & Iron Absorption

Use of Vitamins to Reduce Phytate Inhibition of Iron Absorption


JUN 1975 – James D. Cook, MD and Clement A. Finch, MD, Seattle, WA

Iron Nutrition

“Ascorbic acid is a potent enhancer of iron absorption, not only because of its ability to reduce iron, but also by forming a chelate with ferric iron at low pH which remains soluble at the higher pH of the duodenum.”

“For example, 60 mg of ascorbic acid added to a meal of rice more than tripled absorption of iron, and 150 grams of papaya containing 66 mg of ascorbic acid increased iron absorption more than five fold when taken with a meal of maize.”

Summary statement: “It would seem that changes of civilization have confronted man with a dietary intake of iron inconsistent with his previously established genetic makeup. While improving the iron nutrition of the population seems a worthy cause, its success will depend on further studies of food iron availability and on careful evaluation of the effectiveness of those dietary changes which are undertaken.”


1993 – Center for Medical Research, Caracas, Venezuela

Vitamin A Reduces the Inhibition of Iron Absorption by Phytates and Polyphenols

“These experiments demonstrated that Vitamin A prevented the inhibiting effect of polyphenols and phytates on iron absorption. It was also demonstrated that Vitamin A had the same effect on iron absorption as phytase.”

Summary statement: “This unexpected behavior in reducing the inhibition of iron absorption by phytates is apparently a newly discovered property of Vitamin A.”


2008 – University of Göteborg, Sweden

Iron Absorption in Man

“Iron deficiency is globally the most common form of nutrient deficiency.”

“Adding 20 g of meat, or 20 g of meat and 20 mg ascorbic acid to a meal with low Fe bioavailability increased the total Fe absorption with 155% and 227%, respectively. Improvements in Fe status were greater after dietary modifications than after Fe fortification for a diet with low Fe bioavailability.”

Summary statement: “The overall conclusion of this thesis is that the best course of action for interventions designed to improve Fe status, firstly must be to ensure an adequate dietary Fe bioavailability, and secondly to use a Fe fortificant with high bioavailability.”