MP
l-Methylfolate is converted into methionine and finally into SAMe, which is the direct methyl donor for methylation reactions. If l-methylfolate is defi- cient, so might be SAMe, and it may be possible to administer methionine or SAMe to such patients as well as l-methylfolate. However, administering methionine or SAMe can cause build-up of the unwanted metabolite homocysteine that could theo- retically interfere with epigenetic mechanisms, and can also eventually deplete precursors to SAMe. Nevertheless, high doses of SAMe may be effective in augmenting antidepressants in patients with major depression.