title: The effect of calcium gluconate and other calcium supplements as a dietary calcium source on magnesium absorption in rats.
abstract: The effects of commercially available calcium supplements (calcium carbonate, calcium gluconate, oyster shell preparation and bovine bone preparation) and gluconic acid on the absorption of calcium and magnesium were evaluated for 30 days in male Wistar rats. There were no differences in the apparent absorption ratio of calcium among rats fed each calcium supplement; however, the rats fed the calcium gluconate diet had a higher apparent absorption ratio of magnesium than the rats fed the other calcium supplements. Dietary gluconic acid also more markedly stimulated magnesium absorption than the calcium carbonate diet, and the bone (femur and tibia) magnesium contents of rats fed the gluconic acid diet were significantly higher than those of the rats fed the calcium carbonate diet. Furthermore, the weight of cecal tissue and the concentrations of acetic acid and butyric acid in cecal digesta of rats fed the calcium gluconate diet or the gluconic acid diet were significantly increased. We speculate that the stimulation of magnesium absorption in rats fed the calcium gluconate diet is a result of the gluconic acid component and the effect of gluconic acid on magnesium absorption probably results from cecal hypertrophy, magnesium solubility in the large intestine and the effects of volatile fatty acids on magnesium absorption.
authors.affiliation: Yakult Central Institute for Microbiological Research, Tokyo, Japan.
authors.forename: O
authors.initials: O
authors.lastname: Chonan
authors.forename: R
authors.initials: R
authors.lastname: Takahashi
authors.forename: H
authors.initials: H
authors.lastname: Yasui
authors.forename: M
authors.initials: M
authors.lastname: Watanuki
mesh_terms: D000042:Absorption / Q000187:drug effects / Q000502:physiology; D000818:Animals; D001835:Body Weight / Q000187:drug effects / Q000502:physiology; D001842:Bone and Bones / Q000737:chemistry; D002118:Calcium / Q000493:pharmacokinetics; D002119:Calcium Carbonate / Q000494:pharmacology; D002125:Calcium Gluconate / Q000494:pharmacology*; D002136:Calcium, Dietary / Q000494:pharmacology*; D002417:Cattle; D002432:Cecum / Q000378:metabolism / Q000473:pathology; D004435:Eating / Q000187:drug effects / Q000502:physiology; D005232:Fatty Acids, Volatile / Q000032:analysis; D005269:Femur / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D006965:Hyperplasia; D008274:Magnesium / Q000032:analysis / Q000378:metabolism / Q000493:pharmacokinetics*; D008297:Male; D010758:Phosphorus / Q000493:pharmacokinetics; D051381:Rats; D017208:Rats, Wistar; D013977:Tibia / Q000737:chemistry
chemical_list: D002136:Calcium, Dietary; D005232:Fatty Acids, Volatile; D010758:Phosphorus; D002119:Calcium Carbonate; D008274:Magnesium; D002125:Calcium Gluconate; D002118:Calcium