title: Differential effect of vitamin K and vitamin D supplementation on bone mass in young rats fed normal or low calcium diet.
abstract: The purpose of this study was to clarify the differential effect of vitamin K and vitamin D supplementation on bone mass in young rats fed a normal or low calcium diet. Ninety female Sprague-Dawley rats, 6 weeks of age, were randomized by stratified weight method into nine groups with 10 rats in each group: baseline control, and 0.5% (normal) or 0.1% (low) calcium diet, either alone, or with vitamin K (30 mg/100g, food intake), vitamin D (25 micro g/100 g, food intake), or vitamin K + vitamin D. After 10 weeks of feeding, bone histomorphometric analyses were performed on cortical bone of the tibial shaft and cancellous bone of the proximal tibia. Vitamin K supplementation increased the maturation-related cancellous bone gain and retarded the reduction in the maturation-related cortical bone gain in rats fed a low calcium diet, and increased the maturation-related cortical bone gain in rats fed a normal calcium diet. Vitamin D supplementation reduced the maturation-related cancellous bone gain, prevented the reduction in periosteal bone gain, and enhanced the enlargement of the marrow cavity, with no significant effect on the reduction in the maturation-related cortical bone gain in rats fed a low calcium diet, and increased the maturation- related cancellous and cortical bone gains with increased periosteal bone gain in rats fed a normal calcium diet. An additive effect of vitamin K and vitamin D on the maturation- related cortical bone gain was found in rats fed a normal calcium diet. This study shows the differential effects of vitamin K and vitamin D supplementation on cancellous and cortical bone mass in young rats fed a normal or low calcium diet, as well as the additive effect on cortical bone under calcium sufficient condition.
authors.affiliation: Department of Sports Medicine, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan. jiwamoto@sc.itc.keio.ac.jp
authors.forename: Jun
authors.initials: J
authors.lastname: Iwamoto
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Takeda
authors.forename: Shoichi
authors.initials: S
authors.lastname: Ichimura
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Sato
authors.forename: James K
authors.initials: JK
authors.lastname: Yeh
mesh_terms: D000367:Age Factors; D000818:Animals; D000933:Antifibrinolytic Agents / Q000494:pharmacology*; D015519:Bone Density / Q000187:drug effects*; D001846:Bone Development / Q000187:drug effects*; D002136:Calcium, Dietary / Q000494:pharmacology*; D019587:Dietary Supplements; D005260:Female; D051381:Rats; D017207:Rats, Sprague-Dawley; D014807:Vitamin D / Q000494:pharmacology*; D014812:Vitamin K / Q000494:pharmacology*
chemical_list: D000933:Antifibrinolytic Agents; D002136:Calcium, Dietary; D014812:Vitamin K; D014807:Vitamin D