ARS | Publication request: ZINC ABSORPTION BY RATS FED VARYING AMOUNTS OF METHIONINE

Submitted to: Federation of American Societies for Experimental Biology Conference
Publication Type: Abstract Only
Publication Acceptance Date: March 10, 1995
Publication Date: N/A

Technical Abstract: A whole-body radioassay method was used to assess the effect of supplemental methionine (Met) on zinc bioavailability to rats. Male rats (8/group) that initially weighed about 100 g were fed diets that contained 15% soy protein plus either 0, 1, 2 or 3 g of L-Met added per kg of diet. The sulfur amino acid content of the basal diet without added Met was 0.35%; all diets were marginally Zn deficient (8 mg Zn/kg diet). As indicated by absorption of extrinsic 65Zn added to test meals, the bioavailability to rats of dietary Zn averaged 56, 66, 73 and 72% when the diets contained 0, 1, 2 and 3 g of added Met/kg of diet, respectively. This study indicated that Zn bioavailability to animals fed soy protein was enhanced nearly 33% by supplemental Met; about 2 g Met/kg of diet appeared to be the minimal amount of supplementary Met required to stimulate maximal Zn absorption by marginally Zn-deficient rats. We propose that selection of edible seeds and grains with increased amounts of Met may result in increased Zn bioavailability and thereby increase the nutritional value of these foods. Cereal grains will become more prominent sources of minerals as people implement current dietary recommendations that call for increased consumption of grains and other plant foods.