Discordant effects of vitamin D deficiency in trabecular and cortical bone architecture and strength in growing rodents.
We have previously shown that vitamin D deficiency in young male rats results in significant reduction in femoral trabecular bone volume (BV/TV). However, the effects of vitamin D deficiency and its impact on other relevant skeletal sites remain unclear. Ten week old male Sprague-Dawley rats were fed various levels of vitamin D3 (2, 4, 8, and 12 IU/day) with standard Ca (0.4%) until 30 weeks of age and achieved stable serum 25-hydroxyvitamin D3 (25D) levels between 16 and 117 nmol/L. At time of death, femora, L2 vertebrae and tibiae were processed for bone histomorphometric analyses and tibial cortical strength by 3-point mechanical testing. A significant association between serum 25D and trabecular bone occurred for both the distal femoral metaphysis (R2=0.34, P<0.05) and L2 vertebrae (R2=0.24, P<0.05). Tibia mid-shaft cortical bone was not, however, changed in terms of total volume, periosteal surface or endosteal surface as a function of vitamin D status. Furthermore, no changes to mechanical and intrinsic properties of the cortices were observed. We conclude that cortical bone is maintained under conditions of vitamin D deficiency in preference to cancellous bone in young growing rats.
Lee
Alice M C
AM
School of Medical Sciences, Faculty of Health Sciences, University of Adelaide, Adelaide, Australia.
Anderson
Paul H
PH
Sawyer
Rebecca K
RK
Moore
Alison J
AJ
Forwood
Mark R
MR
Steck
Roland
R
Morris
Howard A
HA
O'Loughlin
Peter D
PD
D000818:Animals; D001835:Body Weight; D015519:Bone Density; D001842:Bone and Bones / Q000378:metabolism; D055119:Elastic Modulus; D008297:Male; D010011:Osteocytes / Q000166:cytology; D051381:Rats; D017207:Rats, Sprague-Dawley; D013314:Stress, Mechanical; D013977:Tibia / Q000473:pathology; D014057:Tomography, X-Ray Computed / Q000379:methods; D014807:Vitamin D / Q000378:metabolism; D014808:Vitamin D Deficiency / Q000378:metabolism*
D014807:Vitamin D