Hyperhomocysteinemia is a medical condition characterized by an abnormally high level of total homocysteine (that is, including homocystine and homocysteine-cysteine disulfide) in the blood, conventionally described as above 15 μmol/L.[1]
As a consequence of the biochemical reactions in which homocysteine is involved, deficiencies of
vitamin B6, folic acid (vitamin B9), and vitamin B12 can lead to high homocysteine levels.[2] Other possible causes of hyperhomocysteinemia include genetics, excessive methionine intake, and other diseases.[3]
Hyperhomocysteinemia is typically managed with vitamin B6, vitamin B9 and vitamin B12 supplementation.[4] Hyperhomocysteinemia is a risk factor for cardiovascular disease; supplements of these vitamins may slightly reduce stroke outcome but not myocardial infarction, death from any cause or adverse events.[5]
^Guo, H; Chi, J; Xing, Y; Wang, P (2009). "Influence of folic acid on plasma homocysteine levels & arterial endothelial function in patients with unstable angina". The Indian Journal of Medical Research. 129 (3): 279–84. PMID19491420.
^Miller, J. W.; Nadeau, M. R.; Smith, D; Selhub, J (1994). "Vitamin B-6 deficiency vs folate deficiency: Comparison of responses to methionine loading in rats". The American Journal of Clinical Nutrition. 59 (5): 1033–9. doi:10.1093/ajcn/59.5.1033. PMID8172087.