Homocysteine is an amino acid that the body produces. Abnormal homocysteine levels may indicate that a person has a deficiency in specific vitamins or a higher chance of developing certain medical conditions.
Most people have low homocysteine levels because the body breaks down the amino acid into usable compounds.
In rare cases, homocysteine could be due to homocystinuria, which is a genetic disease that doctors may test for in a newborn.
Homocystinuria means that the body is not able to process amino acids properly.
According to an older article, normal and abnormal levels of homocysteine can vary between people. However, typically, if a person’s homocysteine levels are less than 13 micromoles/liter (μmol/L), healthcare providers consider them normal.
They also consider homocysteine levels measuring between 13–60 μmol/L as moderately high, and levels between 60–100 μmol/L as severely elevated.
According to a recent review of studies published in the journal
This means that lowering homocysteine levels will not necessarily prevent a particular condition from developing.
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A doctor may recommend a person get a homocysteine level test if they show signs of deficiency in vitamin B-6, B-12, or folate.
A homocysteine test involves drawing blood. However, the test involves separating the blood cells and plasma quickly, so unless a doctor has the facilities to do this in the office, a person may need to go to an outside laboratory to get the blood test.
A person’s healthcare providers should provide instructions on where a person should go for the blood test.
Before the test, a doctor may ask the person fast for 10–12 hours, although they can drink water during this time. The doctor may also ask the person not to take medications or supplements before the test.
If the elevated levels are due to a deficiency in vitamins B-6 and B-12, or folate, a person may experience symptoms such as:
- sores on mouth or tongue
- tingling in the feet, legs, hands, or arms
- pale skin
Vitamin B-6, B-12, and folate deficiencies are a common cause of higher homocysteine levels in some people. But other factors include:
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Potential conditions associated with high homocysteine levels include:
- osteoporosis, which occurs when bones become weaker
- Parkinson’s disease, which is a disorder of the central nervous system
- multiple sclerosis, which is an autoimmune disease that attacks the spinal cord and the brain
- eclampsia, which is the onset of seizures caused due to high blood pressure
- aortic aneurysm, which occurs when an abnormal bulge develops in the aorta
- cardiovascular disease
- heart attack
- atherosclerosis, which is an arterial disease
- end stage renal disease
- hypothyroidism, which is when the body is unable to produce thyroid hormones
A doctor will recommend a blood test for homocysteine levels if the person has symptoms of vitamin B-6, B-12, or folate deficiency. They may also run the test if the person already has risk factors for heart disease.
If a person’s test results come back with high levels of homocysteine, a doctor may need to run additional tests to determine the underlying cause.
In some cases, it may be due to not getting enough nutrients. Other people may have an underlying health condition that needs additional treatment.
Treatment will vary according to the underlying condition. For example, if a person has a vitamin deficiency, a doctor may prescribe or recommend taking supplements to correct the deficiency. They may also recommend the person make dietary changes to help decrease their levels.
Typically, people have low levels of homocysteine in their blood. An elevated level could indicate a deficiency in certain vitamins or folate and may increase a person’s risk of developing cardiovascular disease, cancer, and several other conditions.
It is possible to lower homocysteine levels through dietary changes and by taking supplements. However, a doctor may continue to monitor the person for signs of heart disease or other health conditions.
According to a 2017 review question, no evidence suggests that lowering a person’s homocysteine levels reduces the chance of developing cardiovascular events or cancer. However, the American Heart Association emphasize that a healthful diet can help maintain a healthy heart.