Abstract
BACKGROUND
Short-term measurements of iron absorption are substantially influenced by dietary bioavailability of iron, yet bioavailability negligibly affects serum ferritin in longer, controlled trials.
OBJECTIVE
Our objective was to test the hypothesis that in men fed diets with high or low iron bioavailability, iron absorption adapts to homeostatically maintain body iron stores.
DESIGN
Heme- and nonheme-iron absorption from whole diets were measured in 31 healthy men at 0 and 10 wk while the men consumed weighed, 2-d repeating diets with either high or low iron bioavailability for 12 wk. The diets with high and low iron bioavailability contained, respectively, 14.4 and 15.3 mg nonheme Fe/d and 1.8 and 0.1 mg heme Fe/d and had different contents of meat, ascorbic acid, whole grains, legumes, and tea.
RESULTS
Adaptation occurred with nonheme- but not with heme-iron absorption. Total iron absorption decreased from 0.96 to 0.69 mg/d (P < 0.05) and increased from 0.12 to 0.17 mg/d (P < 0.05) after 10 wk of the high- and low-bioavailability diets, respectively. This partial adaptation reduced the difference in iron bioavailability between the diets from 8- to 4-fold. Serum ferritin was insensitive to diet but fecal ferritin was substantially lower with the low- than the high-bioavailability diet. Erythrocyte incorporation of absorbed iron was inversely associated with serum ferritin.
CONCLUSIONS
Iron-replete men partially adapted to dietary iron bioavailability and iron absorption from a high-bioavailability diet was reduced to approximately 0.7 mg Fe/d. Short-term measurements of absorption overestimate differences in iron bioavailability between diets.
Pub Type(s)
Clinical Trial
Comparative Study
Journal Article
Randomized Controlled Trial
Research Support, Non-U.S. Gov't
TY - JOUR
T1 - Adaptation of iron absorption in men consuming diets with high or low iron bioavailability.
AU - Hunt,J R,
AU - Roughead,Z K,
PY - 2000/1/5/pubmed
PY - 2000/1/5/medline
PY - 2000/1/5/entrez
SP - 94
EP - 102
JF - The American journal of clinical nutrition
JO - Am J Clin Nutr
VL - 71
IS - 1
N2 - BACKGROUND: Short-term measurements of iron absorption are substantially influenced by dietary bioavailability of iron, yet bioavailability negligibly affects serum ferritin in longer, controlled trials. OBJECTIVE: Our objective was to test the hypothesis that in men fed diets with high or low iron bioavailability, iron absorption adapts to homeostatically maintain body iron stores. DESIGN: Heme- and nonheme-iron absorption from whole diets were measured in 31 healthy men at 0 and 10 wk while the men consumed weighed, 2-d repeating diets with either high or low iron bioavailability for 12 wk. The diets with high and low iron bioavailability contained, respectively, 14.4 and 15.3 mg nonheme Fe/d and 1.8 and 0.1 mg heme Fe/d and had different contents of meat, ascorbic acid, whole grains, legumes, and tea. RESULTS: Adaptation occurred with nonheme- but not with heme-iron absorption. Total iron absorption decreased from 0.96 to 0.69 mg/d (P < 0.05) and increased from 0.12 to 0.17 mg/d (P < 0.05) after 10 wk of the high- and low-bioavailability diets, respectively. This partial adaptation reduced the difference in iron bioavailability between the diets from 8- to 4-fold. Serum ferritin was insensitive to diet but fecal ferritin was substantially lower with the low- than the high-bioavailability diet. Erythrocyte incorporation of absorbed iron was inversely associated with serum ferritin. CONCLUSIONS: Iron-replete men partially adapted to dietary iron bioavailability and iron absorption from a high-bioavailability diet was reduced to approximately 0.7 mg Fe/d. Short-term measurements of absorption overestimate differences in iron bioavailability between diets.
SN - 0002-9165
UR - https://www.unboundmedicine.com/medline/citation/10617952/Adaptation_of_iron_absorption_in_men_consuming_diets_with_high_or_low_iron_bioavailability_
L2 - https://academic.oup.com/ajcn/article-lookup/doi/10.1093/ajcn/71.1.94
DB - PRIME
DP - Unbound Medicine
ER -
