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The effect of selective amino acid supplementation on calcium absorption during a low protein diet
Author(s) -
Bihuniak Jessica D,
Sullivan Rebecca R,
Simpson Christine A,
Caseria Donna M,
O'Brien Kimberly O,
Kerstetter Jane E,
Insogna Karl L
Publication year - 2013
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.27.1_supplement.lb283
Subject(s) - dibasic acid , absorption (acoustics) , chemistry , amino acid , calcium , mineral absorption , food science , zoology , biochemistry , endocrinology , medicine , biology , physics , organic chemistry , acoustics , polymer chemistry
Increasing dietary protein intake within a physiologic range stimulates intestinal Ca absorption but it is not known if specific amino acids (AA) or dietary protein as a whole is responsible for this effect. We therefore selectively supplemented a low protein (0.7 g/kg) diet with either aromatic (Trp, Phe, His) or dibasic (Arg, Lys) AA to achieve intakes comparable to the content of a high protein diet (2.1 g/kg) and measured Ca absorption. Fourteen young women were randomized to a placebo‐controlled, doubleblind, cross‐over feeding trial in which each subject ingested, in random order, a 6‐day low protein diet supplemented with aromatic AA, dibasic AA, or methylcellulose capsules (control) after a 10‐day adjustment period. All subjects ingested all 3 diets. Intestinal Ca absorption was measured between days 5 and 6 using dual stable Ca isotopes. There was no difference in Ca absorption between the diet supplemented with aromatic AA and the control diet (22.9±2.0% vs.22.3±1.4% respectively, p = 0.322). However, Ca absorption was significantly higher with dibasic AA supplementation (25.2±1.4% vs. 22.3±1.4%, p = 0.047). Individuals with protein intakes below the RDA may benefit from Arg and Lys supplementation to improve Ca economy.