Hyperhomocysteinemia is a condition related to elevated concentration of a substance known as homocysteine. It has been proven that homocysteine may increase some health risks and complications. Homocysteine is an amino acid that is in our body formed from amino acid known as methionin and it is further processed into another amino acid – cysteine. Cysteine may be converted back to homocysteine or methionine. The conversion of homocysteine to methionine or cysteine requires presence of vitamins B6, B9, B12 and related enzymes.


Accumulation of homocysteine is either caused by deficiency of vitamin B6, vitamin B12 and vitamin B9, or by malfunction of enzymes responsible for the metabolism. Such most known inherited condition is congenital disorder of the enzyme MTFHR (methylenetetrahydrofolate reductase). In addition, increased level of homocysteine is usually found in smokers and chronic alcoholics.


Hyperhomocysteinemia itself is asymptomatic but it is assumed its influence on occurrence of certain diseases, especially cardiovascular. Elevated levels of homocysteine increases risk of both atherosclerosis and heart attack and it is a trombophilic condition (increased blood clotting) with more frequent occurrence of deep vein thrombosis, pulmonary embolism, miscarriages and preeclampsia.


The diagnosis can be confirmed by blood tests with elevated homocysteine level (above 15 micromoles per liter).


The only way to reduce homocysteine levels is healthy diet with adequate intake of the above mentioned vitamins, or regular usage of vitamin supplements. However, the issue of homocysteine is more complicated and it is assumed that too aggressive approach and too sharp drop of homocysteine level may be harmful as well.


Jiri Stefanek, MD  Author of texts: Jiri Stefanek, MD
 Contact: jiri.stefanek@seznam.cz
 Sources: basic text sources