What is homocysteine?

Homocysteine is a naturally occurring amino acid produced as part of the body’s methylation process. The level of homocysteine in the plasma is increasingly being recognised as a risk factor for disease and seen as a predictor of potential health problems such as cardiovascular disease and Alzheimer’s.

The complex metabolism of homocysteine within the body is highly dependent on vitamin derived cofactors, and deficiencies in vitamin B12, folic acid and vitamin B6 are associated with raised homocysteine levels. Other factors thought to raise levels are poor diet, poor lifestyle – especially smoking and high coffee and alcohol intake, some prescription drugs (such as proton pump inhibitors), diabetes, rheumatoid arthritis and poor thyroid function.

There is no consensus about the upper reference limits for plasma homocysteine concentrations although the ‘normal’ range for healthy individuals is considered to be between 5 and 15 µmol/L. However levels as low as 6.3 µmol/L are thought to confer an increased risk and each 5 µmol/L can increase the risk of coronary heart disease events by approximately 20%.

The good news is that homocysteine levels can be tested and high homocysteine levels can, in many cases, be normalised through diet and vitamin supplementation. The most important nutrients that help lower homocysteine levels are folate, the vitamins B12, B6 and B2, zinc and trimethylglycine (TMG).

The process of memory decline and brain shrinkage associated with Alzheimer’s Disease is thought to occur over a 30 to 40 year period, hence the need for screening from age 50. Both high homocysteine (Hcy) levels, and low folic and B12 levels in blood correlate with increasing risk for AD. 

Supplementation to normalise homocysteine levels

Your homocysteine level is a very good indicator of the amount of certain B vitamins, and other nutrients, you need. Homocysteine can be measured by either your GP or through a home test kit. The chart below shows you the approximate level that is worth supplementing on a daily basis.

NutrientVery low riskLow riskAt riskHigh risk
 Below 77–910-15Above 15
Folic Acid200mcg400mcg800mcg800mcg
NAC or Glutathione*250mg500mg750mg
*N-Acetyl Cysteine or glutathione has been shown in studies to help lower homocysteine and improve memory in people with cognitive impairment, given in addition to B12, folic acid and B6.

If your level is below 7 it is still advisable to take a high potency multivitamin and mineral supplement, especially later in life, providing the levels of nutrients shown in the table above for the purposes of maintaining a healthy low level.

If your level is above 7 you will need to take a supplement containing larger amounts of these nutrients, as well as a high potency multivitamin and mineral. Since most of these are water-soluble you are best to divide the dose and take a supplement two or three times a day. The following supplements provide nutrient levels close to these: (the amounts given are per capsule)

 P HolfordHigher NatureSolgar Gold SpecificsBetrinacCytoplan
 Connect* 3 tables provide:H Factors* 2 tablets provide:H Modulators 2 tablets provide: 1 tablet provides:Methyl Factors
Folic AcidMTHfolate 375mcg*400mcg400mcg800mcg800mcg
B230mg15mg 3mg
Zinc15mg10mg 5mg
TMG1500mg750mg1000mg 400mg
NAC or Glutathione750mg600mcg
Higher Nature: adopts a formulae that uses methylB12, which is more bioavailable. B12 absorption tends to decline with age and is poor in some people. Connect: adopts a formulae that uses methylB12 and the methyl form of Folic Acid (B9), which are more bioavailable. The methylated form of folic acid used in this formula is equivalent to 750mcg of unmethylated folic acid. 
These supplements are available in health food stores or by mail order on the web.

After supplementation

Re-test your homocysteine level after three months. If your homocysteine level has dropped then use the table above to identify the revised supplementation required based on that level. If your level drops below 7 stay on a high potency multivitamin that provides these basic levels. Do not keep taking higher levels of B vitamins, especially folic acid, unless required to keep your homocysteine level in check.