Active B12 Factsheet


Vitamin B12 is a water-soluble vitamin.
Vitamin B12 is required for the development, function of the central nervous system, healthy red blood cell formation and DNA synthesis.
Small daily dose of 3μg from B12 food or supplementation is required
Vitamin B12 Deficiency can have serious health risks. Risks include anaemia or nervous system damage. Nervous system damage can’t be reversed.

Optimal Health

Testing for inflammation is essential particularly if you are in an at-risk group.
Daily B12 intake from B12 rich food, mostly animal based products or supplementation.
Daily intake should be 3μg.
Pregnant and Lactating Women need to ensure adequate B12
Over 60’s should supplement.

B12 Deficiency

Approximately 6% of adults below 60 years have vitamin B12 deficiency, with the increasing to 20% for the over 60’s. During pregnancy, vitamin B12 levels tend to drop, sometimes to subnormal levels, usually returning to normal after delivery.

Vegan’s and Vegetarians are at a higher risk of deficiency.

The body can stores about 1 to 5 mg vitamin B12 (1,000 to 2,000 times as much as the amount typically consumed in a day), therefore the symptoms of vitamin B12 deficiency can take several years to appear, however you maybe subclinically deficient. Vitamin B12 deficiency with classic hematologic and neurologic symptoms is uncommon and reversible if detected early. Low vitamin B12 status (200–300 pg/mL [148–221 pmol/L]) without these symptoms is common, with up to 40% in Western populations, especially in those with low intakes of vitamin B12-rich foods.

Symptoms of Deficiency

  • Fatigue
  • Tingling
  • Numbness
  • Confusion
  • Failure to Heal
  • Sore Tongue
  • Reduced sensitivity to pain

Testing B12

Testing for B12 status should include Active B12, Folate, Full Blood Examination and Homocysteine.

Total plasma homocysteine levels, rise quickly as vitamin B12 status declines. A serum homocysteine level higher than 10 micromol/L, is suggestive of vitamin B12 deficiency.

Risk Groups

  • Over 60’s
  • Individuals with pernicious anemia
  • Individuals with gastrointestinal disorders
  • Vegetarians
  • Vegan’s who don’t take daily B12 supplementation
  • Long Term Vegans
  • Infants of vegan women
  • Medications including Gastric acid inhibitors, Proton pump inhibitors & Metformin

Active B12 & Folate

Vitamin B12 and folate are two vitamins that are part of the B complex of vitamins. B12 and folate work with vitamin C to help the body make new proteins. They are necessary for normal red blood cell (RBC) and white blood cell (WBC) formation, repair of tissues and cells, and synthesis of DNA. Both are nutrients that cannot be produced in the body and must be supplied by the diet.

A deficiency of either will disrupt a large number of essential process as they are need together to work effectively. This is why levels are tested together.


Download this factsheet in PDF format here.