Iron absorption by heterozygous carriers of the HFE C282Y mutation associated with hemochromatosis

Abstract

Background: Research conducted before genotyping was possible suggested that subjects heterozygous for the genetic mutation associated with hemochromatosis absorbed nonheme iron more efficiently than did control subjects when tested with a fortified meal. Heme-iron absorption in these subjects has not been reported. Objective: We compared the absorption of heme and nonheme iron from minimally or highly fortified test meals between HFE C282Y-heterozygous and wild-type control subjects. Design: After prospective genotyping of 256 healthy volunteers, 11 C282Y-heterozygous and 12 wild-type control subjects were recruited, and their iron absorption was compared by using a hamburger test meal with or without added iron and ascorbic acid. After retrospective genotyping of 103 participants in previous iron-absorption studies, 5 C282Y-heterozygous subjects were compared with 72 wild-type control subjects. Results: HFE C282Y-heterozygous subjects did not differ significantly from wild-type control subjects in their absorption of either heme or nonheme iron from minimally or highly fortified test meals. No differences were detected in blood indexes of iron status (including serum ferritin, transferrin saturation, and non-transferrin-bound iron) or in blood lipids or transaminases, but heterozygotes had significantly greater, although normal, fasting glucose concentrations than did wild-type control subjects. Compound heterozygotes (those who had both HFE C282Y and H63D mutations) absorbed more nonheme (but not heme) iron from meals with high (but not low) iron bioavailability. Conclusions: HFE C282Y-heterozygous subjects did not absorb dietary iron more efficiently, even when foods were highly fortified with iron from ferrous sulfate and ascorbic acid, than did control subjects. Iron fortification of foods should not pose an additional health risk to HFE C282Y heterozygotes. © 2004 American Society for Clinical Nutrition.