Vegetarians are known to be deficient in vitamin B12, due to a lack or absence of dietary animal produce, which can elevate homocysteine. There is strong evidence indicating that elevated plasma total homocysteine (tHcy) is a contributor to chronic conditions, such as primary cardiovascular disease (CVD). The study hypothesis is: There will be a significant decrease in plasma tHcy of vegetarians following the intervention by supplementary vitamin B12 (of the methylcobalamin type) and this will lead to a reduction of the risk of CVD.

Inclusion Criteria:

• Having a plasma tHcy >10 micromol/L
• Not suffering from conditions as described in exclusion criteria.
• Vegetarian for at least one year.
• Not participating in a weight reducing diet.
• Not consuming regularly vitamin B12 supplements.
• Give written consent to participate in clinical trial and be fluent in English language.

Exclusion Criteria:

• Having a plasma tHcy less or equal to 10 micromol/L.
• Suffering from pernicious anemia or other vitamin B12 deficiency disease.
• Undergone bowel surgery or suffer from gastrointestinal disease.
• Pregnant, lactating or trying to conceive.
• Smoker.
• Alcohol intake regularly greater than official recommended daily units (i.e. 2 units female, 3 units male).
• Consume large amounts of caffeine (regular consumption of >4 cups of strong tea or coffee per day).
• Use of medications known to influence nutritional status.
• Have genetic metabolic disease.
• Suffer from renal failure, diabetes, thyroid disease, cardiovascular disease, dementia or cancer.
• Have a known blood-borne infection (e.g. Hepatitis or HIV).