The basic metabolic role of betaine as a methyl donor
and osmoprotectant has been recognized (Barak et al.,
1993). Recent research findings regarding the
methylation function of betaine have demonstrated that
when one of the two biochemical pathways (Vitamin B12
dependent and independent) in the conversion of
homocysteine to MET is inhibited, betaine can be used to
convert homocysteine to MET in the transmethylation
pathway in the liver (Barak et al., 1996). Betaine needs
no activation once in the cystol and regardless of its
origin, it is used to methylate homocysteine to MET,
through the action of the enzyme betaine homocysteine
methyl transferase (BHMT) (McKeever et al., 1991;