What is homocysteine?
Homocysteine is a sulfur-containing amino acid that is a bioproduct of methionine. It is an important marker in health and disease. Homocysteine is toxic and may be a marker for several chronic diseases.
Elevated levels are thought to be caused by abnormalities in the methylation pathway, which is key for immune regulation and inflammation. Elevated homocysteine is common in deficiencies of vitamins B6, B9 (folate), and B12 - and is an independent risk factor for heart disease, stroke, autoimmune disease, recurrent miscarriage, cancer, leaky blood-brain barrier, dementia, Alzheimer’s disease, Parkinson’s disease, depression, and cognitive impairment.
A homocysteine test is often done alongside an MMA test, a functional test that can detect vitamin B12 deficiency. Several genetic factors can result in irregular homocysteine levels, both high and low.
The reference for high homocysteine is >15. Research shows that optimal levels of homocysteine range from 7 to 11 umol/L. Stroke incidence occurs when homocysteine levels exceed 11 umol/L.
Why test homocysteine?
What causes low homocysteine?
Low homocysteine is known as hypohomocysteinaemia. This can be caused by several factors, including an increase in the production of glutathione (during which the body uses more homocysteine than usual), a low intake of vitamins B9 (folate) and B12, a low intake of amino acids methionine and cysteine, and excessive conversion to another substance called cystathione.
Since animal products are the main source of methionine, vegans, and vegetarians may be at increased risk of low homocysteine. Another reason is an inherently low level of the enzyme MTHFR. Research shows that up to 25% of people suffer from a genetic polymorphism (a type of weakness) in the MTHFR gene.
Low homocysteine may be a sign of oxidative stress if it is caused by the body producing more glutathione in response to oxidative stress.
Symptoms of low homocysteine
Symptoms of low homocysteine levels can include persistent fatigue, cognitive issues, mood changes, poor circulation, and unexplained muscle weakness. Often linked to high levels of B vitamins, maintaining a balanced nutrient intake is essential. If low homocysteine is suspected, consulting a healthcare provider for testing and guidance is recommended.
What causes high homocysteine?
High homocysteine, also known as hyperhomocysteinaemia can cause numerous health issues. High homocysteine can indicate malnutrition and particularly vitamin B12 or folate deficiency, so we strongly recommend testing your B12 and folate levels. People with kidney conditions can have higher homocysteine levels. Stress can temporarily increase homocysteine.
Certain genetic polymorphisms, like MTHFR 677CT are associated with elevated homocysteine, particularly in association with folate deficiency and vitamin B12 deficiency. Homocysteine levels tend to increase with age, smoking, being male, coffee consumption, high blood pressure, higher blood fat and cholesterol levels, high creatinine, and certain medications such as carbamazepine, methotrexate, and phenytoin. Women's concentrations increase after menopause, possibly due to decreased estrogen production. Low estrogen levels can also lower homocysteine.
Having normal homocysteine levels does not rule out other problems. If you are suffering recurrent miscarriages and your homocysteine is normal, there are other tests that we can order (such as S-adenosylhomocysteine (SAH)).
High homocysteine, also known as hyperhomocysteinemia can cause health issues. Even though the reference for high homocysteine is >, research shows that optimal levels of homocysteine ranges from 7 to 11 μmol/L. Stroke incidence occurs when homocysteine levels exceed 11 μmol/L.
High homocysteine increases the risk of ischemic stroke and may be an independent risk factor for heart disease, particularly in people with other risk factors. Studies also suggest that elevated homocysteine levels in the late first trimester (8 to 12 weeks) of pregnancy may affect pregnancy outcomes.
Several studies have found that high homocysteine increases the risk of ischemic stroke and may be an independent risk factor for heart disease, particularly in people with other risk factors. Studies also suggest that elevated homocysteine levels in the late first trimester (8 to 12 weeks) of pregnancy may affect pregnancy outcomes.
Symptoms of high homocysteine
High homocysteine levels can cause fatigue, memory problems, difficulty concentrating, and mood changes like depression and anxiety. It increases the risk of cardiovascular issues, such as heart disease, stroke, and blood clots, and may lead to bone and joint pain, poor circulation, and blurred vision. Consulting a healthcare provider is essential to address these risks.
More information
High homocysteine may increase the risk of heart disease and stroke.
Preparations for this test
No preparation is needed for this test.
On the day of the test
Always take your ID. with you when going to take a test.