Homocysteine

The role of homocysteine in the body

Homocysteine is a sulfur-containing aminoacid, an intermediate product of methionine metabolism (comes from protein foods). Its key functions are:

• Participates in the methylation cycle, which is important for:
• DNA/RNA synthesis.
• Formation of neurotransmitters (serotonin, dopamineDopamine is a neurotransmitter and hormone that plays a key role in the brain's reward system, motivation, pleasure, learning, and movement regulation.Main functions: Stimulates feelings of pleasure and satisfaction. Involved in motivation and decision-making processes. Regulates motor activity. Affects memory, attention, and mood.).
• Detoxification.
• Affects blood vessels: in excess, it damages the endothelium, accelerating atherosclerosis.

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Norm of homocysteine in the blood

Group	Normal Range (µmol/L)
Adults	5–15
Pregnant Women	< 10
Children	< 5

Risk thresholds:

• Moderately elevated: 15-30% risk of thrombosis.
• High: 30-100 → severe complications.

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Elevated homocysteine (hyperhomocysteinemia)

Reasons:

1. Vitamin deficiency:

• B9 (folate), B12, B6 (essential for homocysteine metabolism).

1. Genetics:

• MTHFR mutation (disrupts folate uptake).

1. Lifestyle:

• Smoking, alcohol, excess coffee.
• Physical inactivity.

1. Diseases:

• Kidney failure.
• Psoriasis, hypothyroidism.

Symptoms and consequences:

• Vascular diseases:
• Atherosclerosis, thrombosis, heart attacks/strokes.
• Erectile dysfunction.
• Neurological problems:
• Depression, dementia, Alzheimer’s disease.
• During pregnancy:
• Miscarriages, preeclampsia, neural tube defects in the fetus.

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Reduced homocysteine

It is rare and has no clinical significance.
Possible reasons:

• Hyperthyroidism.
• Taking certain medications (niacin).

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How do I normalize the level?

With increased homocysteine:

1. Vitamin Therapy:

• B9 (folic acid) – 400-1000 mcg / day.
• B12 (methylcobalamin) – 500-1000 mcg / day.
• B6 (pyridoxine) – 10-50 mg / day.

1. Diet:

• Greens (spinach, broccoli), legumes, liver, eggs.
• Restriction of meat (methionine).

1. Lifestyle:

• Smoking/alcohol withdrawal.
• Cardio exercises (30 min / day).

In Genetics (MTHFR):

• Taking active forms of vitamins (methylfolate instead of folic acid).

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When should I take the test?

• Survey for:
• Unexplained thrombosis.
• Cardiovascular diseases at a young age.
• Miscarriage of pregnancy.
• Cognitive disorders.
• Prophylactically after 40 years (especially with heredity).

Important: Homocysteine is not tested in isolation – it is checked together with vitamins B9, B12, creatinine, and lipidogram.

Example:
Homocysteine 25 mmol / l + low B12 → methylcobalamin administration → control after 3 months.