title: Effect of lactulose on calcium and magnesium absorption: a study using stable isotopes in adult men.
abstract: To evaluate the effect of lactulose on calcium (Ca) and magnesium (Mg) absorption, we performed a clinical trial with a double-blind, randomized, crossover design in 24 healthy adult male volunteers. The absorptions of Ca and Mg were evaluated by a single-labeling method using stable isotopes. The test foods, containing lactulose at a dose of 0 g (placebo), 2 g (low-dose), or 4 g (high-dose) together with 300 mg of Ca containing 20 mg of 44Ca, and 150 mg of Mg containing 28 mg of 25Mg, were administered orally. Urine samples were collected for 8 h after the ingestion of the test food. The ratios of stable isotopes in urine (44Ca/40Ca and 25Mg/24Mg) were measured by ICP-MS (inductively coupled plasma-mass spectrometry). The urinary stable-isotopes ratios (44Ca/40Ca and 25Mg/24Mg) increased with lactulose dosage. Significant differences were observed in the Ca ratio between placebo and high-dose lactulose (p<0.01), and in the Mg ratio between placebo and low-dose lactulose and between placebo and high-dose lactulose (p<0.01). Lactulose ingestion did not change the levels of bone-resorption markers (type I collagen cross-linked N-telopeptide and deoxypyridinoline) in urine. The test foods did not cause any side effects. This study demonstrates that lactulose enhances the absorptions of Ca and Mg in adult men.
authors.affiliation: Food Research & Development Laboratory, Morinaga Milk Industry Co., Ltd., Zama, Kanagawa 228-8583, Japan. n_seki@morinagamilk.co.jp
authors.forename: Nobuo
authors.initials: N
authors.lastname: Seki
authors.forename: Hirokazu
authors.initials: H
authors.lastname: Hamano
authors.forename: Yuriko
authors.initials: Y
authors.lastname: Iiyama
authors.forename: Yuzo
authors.initials: Y
authors.lastname: Asano
authors.forename: Sadayuki
authors.initials: S
authors.lastname: Kokubo
authors.forename: Koji
authors.initials: K
authors.lastname: Yamauchi
authors.forename: Yoshitaka
authors.initials: Y
authors.lastname: Tamura
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Uenishi
authors.forename: Hideki
authors.initials: H
authors.lastname: Kudou
mesh_terms: D000328:Adult; D000596:Amino Acids / Q000187:drug effects / Q000652:urine; D000704:Analysis of Variance; D015415:Biomarkers / Q000097:blood / Q000652:urine; D016723:Bone Remodeling / Q000187:drug effects; D002118:Calcium / Q000008:administration & dosage* / Q000378:metabolism* / Q000652:urine; D002127:Calcium Isotopes / Q000008:administration & dosage / Q000652:urine; D024042:Collagen Type I / Q000187:drug effects / Q000652:urine; D003404:Creatinine / Q000652:urine; D018592:Cross-Over Studies; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D004797:Enzyme-Linked Immunosorbent Assay; D005765:Gastrointestinal Agents / Q000008:administration & dosage*; D006801:Humans; D007408:Intestinal Absorption / Q000187:drug effects*; D007792:Lactulose / Q000008:administration & dosage*; D008274:Magnesium / Q000008:administration & dosage* / Q000378:metabolism* / Q000652:urine; D008297:Male; D013058:Mass Spectrometry; D010455:Peptides / Q000187:drug effects / Q000652:urine; D012016:Reference Values
chemical_list: D000596:Amino Acids; D015415:Biomarkers; D002127:Calcium Isotopes; D024042:Collagen Type I; D005765:Gastrointestinal Agents; D010455:Peptides; C052929:collagen type I trimeric cross-linked peptide; D007792:Lactulose; C036020:deoxypyridinoline; D003404:Creatinine; D008274:Magnesium; D002118:Calcium