title: Effect of 1 year B and D vitamin supplementation on LINE-1 repetitive element methylation in older subjects.
abstract: BACKGROUND
  Disturbed DNA methylation is causally related to chronic diseases like cancer and atherosclerosis. B vitamins are cofactors required for methyl group synthesis and may therefore affect DNA methylation. Vitamin D has epigenetic effects. We tested if B and D vitamin supplementation has an effect on genomic long interspersed nuclear element-1 (LINE-1) methylation and the metabolites S-adenosylmethionine (SAM) and S-adenosylhomocysteine (SAH).
  
  
  METHODS
  Fifty subjects (median age 68.0 years) were supplemented with a daily oral dose of B vitamins (500 µg folic acid, 500 µg vitamin B12 and 50 mg vitamin B6), 1200 IU vitamin D and 456 mg calcium. Fasting blood samples were collected before and after 1 year of supplementation. LINE-1 methylation was determined in genomic DNA from blood cells as a surrogate for whole genome methylation. In addition, SAM, SAH and total homocysteine (tHcy) were measured in plasma samples.
  
  
  RESULTS
  Plasma homocysteine decreased significantly after supplementation (12.8 vs. 9.1 µmol/L; p<0.05), whereas SAM, SAH, the SAM/SAH ratio and LINE-1 methylation did not change significantly. LINE-1 methylation was not significantly correlated with SAH, homocysteine or B vitamins.
  
  
  CONCLUSIONS
  Long-term vitamin B supplementation had no effect on LINE-1 methylation in blood cells nor on plasma levels of SAM and SAH. Vitamin B and D supplementation seems to have no effect on DNA methylation, especially in cases where no severe deficiency exists.
authors: University Hospital of the Saarland, Clinical Chemistry and Laboratory Medicine / Central Laboratory, 66421 Homburg, Germany
authors: Ulrich
authors: U
authors: Hübner
authors: Jürgen
authors: J
authors: Geisel
authors: Susanne H
authors: SH
authors: Kirsch
authors: Vera
authors: V
authors: Kruse
authors: Marion
authors: M
authors: Bodis
authors: Cosima
authors: C
authors: Klein
authors: Wolfgang
authors: W
authors: Herrmann
authors: Rima
authors: R
authors: Obeid
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002119:Calcium Carbonate / Q000494:pharmacology; D002762:Cholecalciferol / Q000494:pharmacology*; D019175:DNA Methylation / Q000187:drug effects*; D019587:Dietary Supplements; D004334:Drug Administration Schedule; D005260:Female; D006710:Homocysteine / Q000097:blood; D006801:Humans; D020084:Long Interspersed Nucleotide Elements / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D012435:S-Adenosylhomocysteine / Q000097:blood; D012436:S-Adenosylmethionine / Q000097:blood; D014803:Vitamin B Complex / Q000494:pharmacology*
chemical_list: D006710:Homocysteine; D014803:Vitamin B Complex; D002762:Cholecalciferol; D012436:S-Adenosylmethionine; D012435:S-Adenosylhomocysteine; D002119:Calcium Carbonate