Homocysteine is an amino acid produced from the metabolism of the essential amino acid, methionine, in the liver.
Vitamin B12, vitamin B6, and vitamin B9 (folate) break down homocysteine to generate methionine and cysteine.
High blood homocysteine level and heart disease
Elevated homocysteine promotes atherosclerosis (thickening or hardening of the arteries) through increased oxidant stress, impaired blood vessel cell function, and induction of thrombosis ( blood clot ).
Prospective studies have shown that elevated plasma homocysteine concentrations increase the risk of cardiovascular disease by twofold and the risk of stroke to a lesser degree.
"Normal" levels of homocysteine range from 5 to 15 micromoles per liter (mol/L). People with levels of 50 or higher are at increased risk of cardiovascular events.
Without treatment, elevated homocysteine levels can lead to severe health complications such as
Treatment for high Homocysteine level
Randomized clinical trials have shown that oral supplementation with the combination of folic acid, B6-, and B12-vitamins substantially lowers circulating homocysteine levels.
A high plant-protein diet decreases the risk of hyperhomocysteinemia since the Proteins of animal foods contain about two to three times as much methionine ( Homocysteine precursor) as proteins from plant foods.