Majid Koozehchian, M.S.Homocysteine (Hcy) is a non-proteinogenic amino acid (i.e., an amino acid not used in proteins) normally present in the blood. Hcy is a by-product of normal diet but high levels in the blood can endanger cardiovascular health. It is formed from methionine, a proteinogenic amino acid, and can biosynthesize back to methionine or into cysteine, another proteinogenic amino acid, as well as several other substances. Benefits of Hcy are unknown; however, its harmful effects...