A homocysteine test is a simple blood test requiring a small blood sample. The test measures the level of homocysteine, an amino acid, in your blood. It is used to diagnose a vital process in the body and brain called methylation. Methylation depends on sufficient vitamins B6, B12, and folic acid. Hence, homocysteine is the best ‘functional’ test for whether a person has sufficient B vitamin status.
If you would like to understand more about Homocysteine and what it is, please watch this short, 10-minute video by our founder, Patrick Holford.
Measuring your homocysteine level is extremely important because elevated homocysteine, above 10µmol/L and probably above 8 or 9µmol/L in pregnancy, is a biomarker for over 100 diseases. It is especially relevant for mental and neurological conditions from dementia to depression, ADHD to autism, but also for neurological conditions from multiple sclerosis to Parkinson’s. Homocysteine is also a biomarker for cardiovascular health, stroke risk, bone health (including conditions like osteoporosis), kidney function, and even conditions such as hypothyroidism. For a complete list of conditions associated with raised homocysteine and the evidence to support this, see the paper – ‘Homocysteine – from disease biomarker to disease prevention’
A normal homocysteine level typically falls within the range of 9 µmol/L or lower. It tends to go up with age. During pregnancy, a level below 8µmol/L is advisable. Levels exceeding 11 µmol/L are associated with accelerated brain shrinkage. When your homocysteine level exceeds 10 µmol/L, it’s advisable to consider supplementation with B vitamins to help bring it within the optimal range.
Methylation is a simple biochemical process in the body in which a methyl group – consisting of one carbon atom and three hydrogen atoms – transfers from one substance to another. It’s an important process as it can significantly alter the function or activity of molecules. It, therefore, ‘activates’ many nutrients, hormones, neurotransmitters, and genes, fundamentally turning genes on and off. Read more about methylation in our blog post “Methylation: Why is it important for mental health?”
The connection between methylation, homocysteine, and B vitamins is essential because B vitamins are crucial components in the methylation process, vital in regulating optimal homocysteine levels in the body.
Specifically, vitamins B12, B6, and folic acid convert homocysteine into S-adenosyl methionine (SAMe), an amino acid considered to be the conductor of the methylation orchestra. This conversion is a crucial part of the methylation cycle, and without adequate B vitamins, homocysteine can elevate, leading to potential health risks. Homocysteine is, itself, a toxic amino acid in the blood vessels and brain, as well as raised homocysteine indicating sub-optimal methylation. Therefore, maintaining sufficient levels of these B vitamins is essential for proper methylation and keeping homocysteine levels in check.
The recommended daily supplementation for optimal homocysteine levels is 400 mcg of folic acid (preferably methyl folate), 500 mcg of B12, and 20mg of B6. These recommendations are grounded in scientific evidence and studies in nutritional neuroscience, including recent research conducted by Professors David Smith, Helga Refsum, and others in their 2021 study. A copy of their research can be found here. For further information on maintaining optimal homocysteine levels, please read our article on ‘Homocysteine-lowering B Vitamins’.
Yes, the homocysteine test methods employed are accurate and scientifically validated. Please see our validation document here.
While most research on homocysteine has tested the plasma (the clear part of the blood), ours uses a dry whole-blood method called LCMS, which has been validated against plasma homocysteine.
Elevated homocysteine levels are linked to a broad spectrum of health risks, serving as a biomarker for over 100 diseases. These risks encompass cardiovascular disease, stroke, diabetes, dementia (including Alzheimer’s disease), and various neurological and mental health conditions.
Monitoring and managing homocysteine levels are crucial to assessing and reducing these health risks.
Yes, several dietary and lifestyle factors can significantly influence homocysteine levels. Diet plays a crucial role: a diet rich in B vitamins, including B6, B12, and folate, effectively lowers homocysteine levels. We recommend eating foods such as leafy greens, meat, fish, eggs, vegetables, seeds and nuts. Both caffeine and alcohol consumption raise homocysteine levels. This occurs with as little as one double expresso or two shots of coffee and wine above a small glass (125ml). Reducing or eliminating caffeine and alcohol consumption can also be instrumental in homocysteine control, as excessive alcohol intake can disrupt B vitamin metabolism. Smoking is also associated with increased homocysteine levels. Stopping smoking is not only beneficial for overall health but also vital to lowering homocysteine. Stress, insomnia, and a lack of or excessive exercise are also associated with raised homocysteine levels.
Medications such as antacid proton pump inhibitors (PPIs), the diabetes drug metformin, and diuretics prescribed for high blood pressure also raise homocysteine.
Read more on this topic in our article “Seven Steps to Keep Your Homocysteine Low.”
—
The test is available in EU countries, but you are responsible for any extra duties your country will require to import the kit. This varies from country to country; they may or may not request this. You will need to show the invoice/receipt from your purchase. Your kit will include a return paid envelope valid for EU countries.
We are working on launching homocysteine testing in North America (e.g., Canada and the US) by mid-2024.
Some drugs (e.g., antibiotics), coffee, nicotine (cigarettes and e-cigarettes), and alcohol could increase homocysteine concentration. We recommend not having these for at least two hours before the test and, ideally, 12 hours along with overnight fasting.
Since the B vitamins B6, folate, and B12 all help lower homocysteine, avoiding supplementation for 24 hours before the test may provide a truer reflection of your homocysteine level. Certainly, avoid taking supplements containing these B vitamins for 12 hours before the test.
Yes. We recommend overnight or 12 hours fasting beforehand, e.g., dinner by 8 pm if you’re taking the blood sample at 8 am. A high protein meal containing the amino acid methionine just before a test would push up your homocysteine level as your body turns methionine into homocysteine, then S-adenosyl methionine (SAMe). This process requires folate and B12, thus ‘challenging’ your methylation ability. Most studies, and therefore most research, is done on fasting samples to minimise this variable factor.
Drink only water before you make the pinprick blood draw/drop.
Given the recommendations above, taking a sample in the morning, before breakfast, is the most practical. Provided you follow the advice above, the time of day does not matter.
No. Homocysteine level is an important determinant of health at any age.
Certain medications, such as antibiotics, can interfere with the test results; thus, we recommend a 12-hour gap from the last dose to draw the blood sample. If your antibiotic dosing is more frequent, we recommend delaying homocysteine testing until your course ends.
Metformin (for diabetes), proton pump inhibitor (PPI) medication to lower stomach acid, and diuretics all lower circulating B vitamins, while supplementing B6, B12, and folic acid or folate increases these homocysteine-lowering nutrients. Therefore, it is best to neither take these medications nor supplements for 12 hours before the test unless otherwise instructed by your doctor. Avoiding them for 24 hours is even more preferable.
The Cognitive Function Test and the subsequent questionnaire gather certain information. This includes any conditions associated with raised homocysteine, medication that lowers B vitamins, and drinks such as coffee and alcohol that tend to increase homocysteine.
The shelf life of the kit is over a year. Please see the date on the kit.
—
The homocysteine test takes longer than others, so please allow 2 to 4 weeks from the date our laboratory receives your sample. You will be notified in an email when we receive the sample.
Homocysteine is a biomarker for over 100 diseases, but it is not diagnostic of them. As listed above, this research paper lists these diseases.
If you have one of these conditions, do notify your healthcare practitioner that your homocysteine level is high and print out or show them the link to this paper.
Please read Lowering Homocysteine with Supplements.
In levels above 10µmol/L, supplementation is recommended.
Eating foods rich in B6, folate, and B12 is also recommended.
B12 is found in food such as fish, meat, milk, and eggs.
Folate and B6 are rich in seeds, nuts, beans, lentils, vegetables, and especially greens.
As requested above, please read Lowering Homocysteine with Supplements.
Homocysteine can be lowered quite rapidly with supplementation, certainly within three months. Therefore, if your level is above 10, it is wise to retest after three months, having taken the recommended actions. Otherwise, a yearly retest would suffice to ensure your homocysteine level remains optimal.
We provide information to help you normalise your homocysteine level. As an educational charity, we provide information regarding optimal diet, supplementation, and lifestyle for robust mental health. We do not provide personalised guidance based on your circumstances; however, we provide a list of practitioners qualified to do so at our Brain Bio Centre, including details regarding their speciality.