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ARS Home » Plains Area » Grand Forks, North Dakota » Grand Forks Human Nutrition Research Center » Healthy Body Weight Research » Research » Publications at this Location » Publication #97243
Title: ADAPTATION IN IRON ABSORPTION: DAILY IRON SUPPLEMENTS REDUCE NONHEME, BUT NOT HEME IRON ABSORPTION FROM A MEAT-BASED MEAL

Author
item Hunt, Janet
item Roughead, Zamzam

Submitted to: Experimental Biology
Publication Type: Abstract Only
Publication Acceptance Date: 4/17/1999
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: Human adaptation in iron absorption was evaluated by measuring iron absorption in healthy volunteers before and after 12 wk of iron supple- mentation. Men and women (n=57, 22 to 58 y) with normal hemoglobin and initial serum ferritin values from 10-230 ug/L were recruited form the community and randomly assigned to consume daily capsules containing either r50 mg iron (as ferrous sulfate) ir placebo, with their evening meals. Iro absorption was measured form a test meal containing (by analysis) 1.2 mg heme iron and 5.1 mg total iron from ground beef, a wheat roll, French- fried potatoes, and a vanilla milkshake, consumed on two consecutive mornings before and again at the nd of the 12 wk of supplementation. Heme and nonheme iron absorption from the test meal were measured with Fe-55 (as rabbit hemoglobin) and Fe-59 (as FeCl3) radiotracers, by using whole body scintillation counting and the ratio of Fe-55/Fe-59 in blood after 2 wk. Data from an analysis of variance (ANOVA) are expressed as LS geometric means (-2SE, +2SE). Iron absorption placebo, wk 0 placebo, wk 12 Iron, wk 0 Iron, wk 12 Heme, % 25 (22, 28) 23 (21, 26) 22 (20, 25) 19(17, 22) Nonheme, % 5.2(4.4-6.0) 5.0(4.3, 5.8) 5.0(4.4,5.8)3.2(2.8,3.7) The absorption of nonheme iron frm food decreased significantly (p<0.001) by about 36% afer 12 wk of iron supplementation. A slight reduction in heme iron absorption with time in the study was not significantly related to the supplementatin treatment. In conclusion, daily iron supplementation reduces the efficieny of nonheme, but no heme iron absorption from food. Partially supported by a grant from the National Cattlemen's Beef Association.