title: Skeletal and hepatic changes induced by chronic vitamin A supplementation in cats.
abstract: The first aim of this study was to determine whether vitamin D supplementation influenced the effects of high vitamin A intake on new bone formation in adult cats. The second aim was to determine whether high vitamin A intake in cats caused liver pathology and, if so, whether the current upper limit for the dietary intake of vitamin A for healthy adult cats would be safe. Twenty-four healthy adult cats were divided into four groups that received a control diet supplemented with peanut oil (control), or peanut oil containing a 100-fold increase in vitamin A (HA), or a 100-fold increase in vitamin A and a fivefold increase in vitamin D (HAMD), or a 100-fold increase in vitamin A and a 65-fold increase in vitamin D (HAHD) over a period of 18 months. Cats did not show abnormal locomotion or clinical signs of liver failure after 18 months of supplementation but did show subtle skeletal changes and liver pathology, suggesting that the current National Research Council (2006) safe upper limit for vitamin A for cats is too high. The addition of vitamin D did not seem to influence bone pathology. While moderately elevated dietary vitamin D levels (HAMD) seemed to protect cats against the liver pathology caused by the consumption of large amounts of vitamin A, higher dietary levels of vitamin D (HAHD) did not seem to be protective.
authors.affiliation: Department of Clinical Sciences of Companion Animals, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands. Electronic address: r.j.corbee@uu.nl.
authors.forename: R J
authors.initials: RJ
authors.lastname: Corbee
authors.affiliation: Department of Clinical Sciences of Companion Animals, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands.
authors.forename: M A
authors.initials: MA
authors.lastname: Tryfonidou
authors.affiliation: Department of Pathobiology, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands.
authors.forename: G C M
authors.initials: GC
authors.lastname: Grinwis
authors.affiliation: Department of Clinical Sciences of Companion Animals, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands.
authors.forename: B
authors.initials: B
authors.lastname: Schotanus
authors.affiliation: Department of Biochemistry and Cell Biology, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands.
authors.forename: M R
authors.initials: MR
authors.lastname: Molenaar
authors.affiliation: Department of Clinical Sciences of Companion Animals, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands.
authors.forename: G
authors.initials: G
authors.lastname: Voorhout
authors.affiliation: Department of Biochemistry and Cell Biology, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands.
authors.forename: A B
authors.initials: AB
authors.lastname: Vaandrager
authors.affiliation: Department of Clinical Sciences of Companion Animals, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands.
authors.forename: H C M
authors.initials: HC
authors.lastname: Heuven
authors.affiliation: Department of Clinical Sciences of Companion Animals, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands.
authors.forename: H A W
authors.initials: HA
authors.lastname: Hazewinkel
mesh_terms: D000821:Animal Feed / Q000032:analysis; D000818:Animals; D001842:Bone and Bones / Q000187:drug effects*; D002415:Cats / Q000378:metabolism*; D004032:Diet / Q000662:veterinary; D019587:Dietary Supplements / Q000032:analysis; D004305:Dose-Response Relationship, Drug; D005260:Female; D008099:Liver / Q000187:drug effects*; D008297:Male; D011897:Random Allocation; D014801:Vitamin A / Q000008:administration & dosage / Q000494:pharmacology*; D014807:Vitamin D / Q000008:administration & dosage / Q000494:pharmacology*; D014815:Vitamins / Q000008:administration & dosage / Q000494:pharmacology*
chemical_list: D014815:Vitamins; D014801:Vitamin A; D014807:Vitamin D
keywords: Fibrosis; Hepatic stellate cells; Hyperostosis; Hypervitaminosis