Betaine and homocysteine

In a randomized crossover study, 8 healthy males (22–36 y) consumed either a betaine-rich diet (800 mg/day) or a betaine supplement (0.5 g twice daily) for 14 days. Fasting blood samples were collected on day −5, −1 (pre-treatment) 0, 2, 6, 9, 13 (treatment), 14 and 18 (post-treatment). Post-methionine load blood samples were collected on day −5, 0, 6 and 13, while 24 h urine samples were collected on day −5, 0, 6, 13 and 14. Plasma betaine, dimethylglycine, homocysteine and urine betaine, dimethylglycine and creatinine concentrations were measured.

Plasma betaine concentrations significantly increased for both treatments compared to pre-treatment values (P < 0.001). Fasting homocysteine levels were minimally affected. Both treatments reduced post-methionine load homocysteine and this effect tended to be greater following a betaine-rich diet (P = 0.108). Small increases in urinary betaine excretion were observed following both treatments (≈1.5% of supplement; ≈1.3% of dietary betaine). Most was attributable to increased excretion of betaine as dimethylglycine.

Therefore, supplemental or dietary betaine similarly increase circulating betaine concentrations and attenuate the post-methionine load rise in homocysteine concentrations.

Atkinson et al (2009). "Dietary and supplementary betaine: Effects on betaine and homocysteine concentrations in males." Nutr Metab Cardiovasc Dis. Apr 3 Epub.