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An inulin‐type fructan enhances calcium absorption in young adults throughout the GI tract with the largest effect occurring in the colon
Author(s) -
Abrams Steven A,
Hawthorne Keli,
Aliu Oluseyi,
Hicks Penni,
Chen Zhensheng,
Griffin Ian
Publication year - 2007
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.21.5.a175
Subject(s) - calcium , calcium metabolism , chemistry , absorption (acoustics) , fructan , inulin , endocrinology , medicine , ingestion , zoology , biochemistry , biology , materials science , sucrose , composite material
Background: Calcium absorption efficiency and bone mineral mass are increased in adolescents who receive inulin‐type fructans (ITF). The mechanism of action is unknown but in animal models appears to be related to increased colonic calcium absorption. Methods: We conducted a calcium kinetic study in young adults after dosing 42Ca orally and also giving 46Ca IV. Kinetic measurements were performed before and after 6 weeks of supplementation with 8 g/d of a mixed short and long degree of polymerization (DP) ITF. Blood samples were collected over 26 hours and a 48‐hour urine collection obtained. The area under the curve of the oral tracer in the blood was calculated and relative increased absorption throughout the sampling period determined. Results: Eight young adults (of 13 studied), with average calcium intake about 900 mg/d responded to the ITF with an increased calcium absorption of at least 3%. The average increase in absorption was 8.3% (72 mg/d). Colonic absorption, defined as absorption that occurred more than 7 hours after oral dosing, represented 60–67% of the increase, or about 45 mg/d calcium absorption in the colon. Discussion: These findings suggest that multiple mechanisms account for the increased calcium absorption associated with the ingestion of a mixed long and short DP ITF. These likely include increased solubility and increased absorptive surface area throughout the intestine.