Elevated Homocysteine is a useful marker to determine if there are issues around methylation and methionine metabolism.
Sample: blood (plasma)
Homocysteine is a non-essential amino acid which is produced in the body through the metabolism of methionine. There are two main routes through which it can be cleared from the body - via the trans-sulphuration pathway to cysteine (dependant upon vitamin B6) or re-methylation to methionine (dependant upon B12, folate and B2). Elevated homocysteine therefore is an indicator that there is either a nutritional deficiency in one of these cofactor nutrients or a genetic SNP or similar 'block' which may be stopping a pathway from working efficiently.
The methionine / homocysteine cycle plays an important role in the production of methyl groups, which are used throughout the body for a range of important processes including DNA expression, hormone activation, neurotransmitter function and gut membrane integrity. It is for this reason that homocysteine is increasingly being recognised as a useful marker for health.
Repeat testing can be used to monitor nutritional interventions aimed at bringing homocysteine levels back within optimal range.
Homocysteine is not a component of food or nutritional supplements, so the patient should not fast prior to the test but we do recommend avoiding B vitamin containing supplements for 24-48 hours. The blood sample should ideally be taken at midday, three to four hours after a protein-containing breakfast (such as eggs, protein shake, cheese, bacon, salmon, tofu), so as to ensure an adequate methionine challenge (equivalent to about 0.5 gm of methionine).
If not attending Biolab in London, a kit containing a Lavender (EDTA) tubes containing a special inhibitor will be provided.
Postal samples done at home must reach Biolab within 48 hours of collection. Please note that samples should only be posted on Monday - Thursday for Friday delivery - this avoids samples being delayed over the weekend period.