title: Experimental folate and vitamin B12 deficiency does not alter bone quality in rats.
abstract: Hyperhomocysteinemia (HHCY) has been linked to fragility fractures and osteoporosis. Folate and vitamin B(12) deficiencies are among the main causes of HHCY. However, the impact of these vitamins on bone health has been poorly studied. This study analyzed the effect of folate and vitamin B(12) deficiency on bone in rats. We used two groups of rats: a control group (Co, n = 10) and a vitamin-deficient group (VitDef, n = 10). VitDef animals were fed for 12 wk with a folate- and vitamin B(12)-free diet. Co animals received an equicaloric control diet. Tissue and plasma concentrations of homocysteine (HCY), S-adenosyl-homocysteine (SAH), and S-adenosyl-methionine (SAM) were measured. Bone quality was assessed by biomechanical testing (maximum force of an axial compression test; F(max)), histomorphometry (bone area/total area; B.Ar./T.Ar.], and the measurement of biochemical bone turnover markers (osteocalcin, collagen I C-terminal cross-laps [CTX]). VitDef animals developed significant HHCY (Co versus VitDef: 6.8 +/- 2.7 versus 61.1 +/- 12.8 microM, p < 0.001) that was accompanied by a high plasma concentration of SAH (Co versus VitDef: 24.1 +/- 5.9 versus 86.4 +/- 44.3 nM, p < 0.001). However, bone tissue concentrations of HCY, SAH, and SAM were similar in the two groups. Fmax, B.Ar./T.Ar., OC, and CTX did not differ between VitDef and Co animals, indicating that bone quality was not affected. Folate and vitamin B(12) deficiency induces distinct HHCY but has no effect on bone health in otherwise healthy adult rats. The unchanged HCY metabolism in bone is the most probable explanation for the missing effect of the vitamin-free diet on bone.
authors.affiliation: Department of Clinical Chemistry and Laboratory Medicine, University Hospital of Saarland, Homburg, Germany. markusherr@aol.com
authors.forename: Markus
authors.initials: M
authors.lastname: Herrmann
authors.forename: Britt
authors.initials: B
authors.lastname: Wildemann
authors.forename: Alexandra
authors.initials: A
authors.lastname: Wagner
authors.forename: Martin
authors.initials: M
authors.lastname: Wolny
authors.forename: Heike
authors.initials: H
authors.lastname: Schorr
authors.forename: Omid
authors.initials: O
authors.lastname: Taban-Shomal
authors.forename: Natalia
authors.initials: N
authors.lastname: Umanskaya
authors.forename: Steffen
authors.initials: S
authors.lastname: Ross
authors.forename: Patric
authors.initials: P
authors.lastname: Garcia
authors.forename: Ulrich
authors.initials: U
authors.lastname: Hübner
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Herrmann
mesh_terms: D000818:Animals; D015415:Biomarkers / Q000097:blood; D001696:Biomechanical Phenomena; D001835:Body Weight; D016723:Bone Remodeling; D001842:Bone and Bones / Q000503:physiopathology*; D004195:Disease Models, Animal; D005260:Female; D005494:Folic Acid Deficiency / Q000097:blood / Q000139:chemically induced / Q000150:complications* / Q000503:physiopathology*; D006710:Homocysteine / Q000097:blood / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D012435:S-Adenosylhomocysteine / Q000097:blood; D012436:S-Adenosylmethionine / Q000097:blood; D014806:Vitamin B 12 Deficiency / Q000097:blood / Q000139:chemically induced / Q000150:complications* / Q000503:physiopathology*
chemical_list: D015415:Biomarkers; D006710:Homocysteine; D012436:S-Adenosylmethionine; D012435:S-Adenosylhomocysteine