Folate supplementation does not affect biochemical markers of bone turnover.
BACKGROUND
Recently, increased plasma homocysteine (HCY) has been suggested as a novel independent risk factor for osteoporotic fractures. This study aimed to analyze the effect of a HCY lowering therapy by folic acid (FA) supplementation on biochemical bone markers in healthy subjects.


METHODS
We treated 61 healthy individuals (mean age: 58+/-8 years) with placebo, 0.4, 1 or 5 mg FA daily for 2 months. Fasting blood samples were taken after 0, 4 and 8 weeks. Serum HCY, folate, vitamin B12, osteocalcin (OC), procollagen type I N-terminal propeptide (PINP) and C-terminal telopeptides of human collagen type I (CTX) were studied.


RESULTS
Overall baseline HCY and folate levels were 13.4 +/- 3.6 micromol/L and 5.7 +/- 3.0 microg/L, respectively. Participants exhibited normal baseline OC, PINP and CTX levels. Serum folate increased during supplementation (4 weeks of placebo, 0.4, 1 and 5 mg of FA: -7, +160, +162 and +436 %; 8 weeks: -6, +305, +340 and +216 %) and HCY decreased (4 weeks of placebo, 0.4, 1 and 5 mg of FA: +2, -14, -21 and -17 %; 8 weeks: +2, -8, -20 and -17 %) in the treatment groups, but not in the placebo group. OC (placebo: 22.8 vs. 23.0 vs. 23.6; 0.4 mg FA: 21.6 vs. 22.1 vs. 24.1; 1 mg FA: 23.7 vs. 22.6 vs. 23.4; 5 mg FA: 24.1 vs. 20.5 vs. 20.9 microg/L), PINP (placebo: 43.5 vs. 51.3 vs. 46.5; 0.4 mg FA: 34.0 vs. 34.1 vs. 39.5; 1 mg FA: 43.6 vs. 39.7 vs. 43.2; 5 mg FA: 41.1 vs. 38.7 vs. 37.4 microg/L) and CTX (placebo: 258 vs. 360 vs. 321; 0.4 mg FA: 229 vs. 290 vs. 315; 1 mg FA: 319 vs. 325 vs. 301; 5 mg FA: 293 vs. 321 vs. 304 ng/L) did not change throughout the study.


CONCLUSIONS
Short-term FA supplementation does not affect biochemical bone markers in non-osteoporotic subjects with a low folate status.
Herrmann
Markus
M
Abteilung für Klinische Chemie und Laboratoriumsmedizin / Zentrallabor, Universitätsklinikum des Saarlandes, D-66421 Homburg/Saar, Germany. markusherr@aol.com
Stanger
Olaf
O
Paulweber
Bernhard
B
Hufnagl
Clemens
C
Herrmann
Wolfgang
W
D015415:Biomarkers / Q000378:metabolism; D016723:Bone Remodeling / Q000187:drug effects*; D001842:Bone and Bones / Q000187:drug effects* / Q000378:metabolism; D003094:Collagen / Q000097:blood; D024042:Collagen Type I; D004032:Diet; D004305:Dose-Response Relationship, Drug; D005260:Female; D005492:Folic Acid / Q000008:administration & dosage* / Q000097:blood; D006710:Homocysteine / Q000097:blood; D006801:Humans; D008297:Male; D008875:Middle Aged; D015675:Osteocalcin / Q000097:blood; D010446:Peptide Fragments / Q000097:blood; D010455:Peptides / Q000097:blood; D011347:Procollagen / Q000097:blood; D014805:Vitamin B 12 / Q000097:blood; D014803:Vitamin B Complex / Q000008:administration & dosage*
D015415:Biomarkers; D024042:Collagen Type I; D010446:Peptide Fragments; D010455:Peptides; D011347:Procollagen; C052929:collagen type I trimeric cross-linked peptide; C047202:procollagen Type I N-terminal peptide; D006710:Homocysteine; D015675:Osteocalcin; D014803:Vitamin B Complex; D003094:Collagen; D005492:Folic Acid; D014805:Vitamin B 12