title: Dietary phosphorus restriction to half the minimum required amount slightly reduces weight gain and length of tibia, but sustains femur mineralization and prevents nephrocalcinosis in female kittens.
abstract: The effects of dietary P restriction to half the recommended minimum level on growth, bone and renal mineralization and urinary composition were studied in female kittens. In two separate experiments, 8-week-old weanling kittens were fed on purified diets containing either 4.6 or 9.2 mmol P/MJ (2.8 or 5.6 g P/kg diet). In the second experiment there was an additional low-P diet in which the Ca concentration was reduced from 9.5 to 4.8 mmol/MJ (7.5 v. 3.8 g Ca/kg diet). P restriction slightly but systematically reduced weight gain (to a maximum of 16%) and growth of the tibia (by 1-4%); the former effect was statistically significant (P < 0.05) between the ages of 15 and 20 weeks in Expt 1 only, and the latter did not reach statistical significance at any time point (P > or = 0.13). No adverse effect of P restriction was found on mineralization of femur at the age of 39 weeks. Kidney Ca concentrations were significantly lowered (Expt 1, 6 v. 20 mumol/g dry weight, P < 0.001; Expt 2, 7 v. 16 mumol/g dry weight, P < 0.01) in cats fed on the low-P diets, this effect not being affected by the dietary Ca:P ratio. Urinary P concentration was significantly depressed (by 50-96%) after feeding the low-P diets (P < 0.001). P intake did not influence P, Ca and Mg retention during the period of 15 to 39 weeks of age.
authors.affiliation: Department of Laboratory Animal Science, Faculty of Veterinary Medicine, Utrecht University, The Netherlands.
authors.forename: F J
authors.initials: FJ
authors.lastname: Pastoor
authors.forename: R
authors.initials: R
authors.lastname: Opitz
authors.forename: A T
authors.initials: AT
authors.lastname: Van 't Klooster
authors.forename: A C
authors.initials: AC
authors.lastname: Beynen
mesh_terms: D000818:Animals; D002113:Calcification, Physiologic; D002118:Calcium / Q000032:analysis; D002371:Cat Diseases / Q000517:prevention & control*; D002415:Cats; D005260:Female; D005269:Femur / Q000502:physiology*; D007668:Kidney / Q000378:metabolism; D009397:Nephrocalcinosis / Q000517:prevention & control / Q000662:veterinary*; D010758:Phosphorus / Q000652:urine; D016226:Phosphorus, Dietary / Q000008:administration & dosage* / Q000378:metabolism; D013977:Tibia / Q000254:growth & development*; D015430:Weight Gain
chemical_list: D016226:Phosphorus, Dietary; D010758:Phosphorus; D002118:Calcium