Ascorbic acid prevents the dose-dependent inhibitory effects of polyphenols and phytates on nonheme-iron absorption

doi:10.1093/ajcn/53.2.537

The American Journal of Clinical Nutrition

Volume 53, Issue 2, February 1991, Pages 537-541

https://doi.org/10.1093/ajcn/53.2.537 Get rights and content

ABSTRACT

The effects of maize-bran phytate and of a polyphenol (tannic acid) on iron absorption from a white-bread meal were tested in 199 subjects. The phytate content was varied by adding different concentrations of phytate-free and ordinary maize bran. Iron absorption decreased progressively when maize bran containing increasing amounts of phytate phosphorous (phytate P) (from 10 to 58 mg) was given. The inhibitory effect was overcome by 30 mg ascorbic acid. The inhibitory effects of tannic acid (from 12 to 55 mg) were also dose dependent. Studies suggested that ≥ 50 mg ascorbic acid would be required to overcome the inhibitory effects on iron absorption of any meal containing > 100 mg tannic acid. Our findings indicate that it may be possible to predict the bioavailability of iron in a diet if due account is taken of the relative content in the diet of the major promoters and inhibitors of iron absorption.

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Ascorbic acid prevents the dose-dependent inhibitory effects of polyphenols and phytates on nonheme-iron absorption

ABSTRACT

Am J Clin Nutr

Am J Clin Nutr

Am J Clin Nutr

Nutr Res

J Nutr

J Nutr

Lancet

Am J Clin Nutr

J Nutr

J Nutr

Am J Clin Nutr

Am J Clin Nutr

Bioavailability of dietary iron in man.

Annu Rev Nutr

Iron metabolism in man

Bioavailability of iron from Western-type whole meals.

Scand J Gastroenterol

The problem of food and nutrition in Africa.

World Rev Nutr Diet