For the maintenance of normal homocysteine levelshomocysteine is a harmful amino acid produced in the body normally the body rapidly converts homocysteine into a harmless substance called cystathionine but smoking getting older running short of b vitamins and drinking too much tea or coffee may reduce our ability to keep homocysteine in our blood within the normal rangesome scientists now believe that maintaining homocysteine within the normal range helps maintain a healthy heart and arter