Question 1

What B12 level is too low?

Accepted Answer

Below about 200 pg/mL (148 pmol/L) is usually considered deficient. Between 200 and 300 pg/mL (148 to 221 pmol/L) is borderline, and further tests such as methylmalonic acid help decide whether you are truly short of B12.

Question 2

Can low B12 cause tiredness and tingling?

Accepted Answer

Yes. Tiredness, pins and needles, numbness and balance problems are common signs of B12 deficiency. Tell your clinician about nerve symptoms promptly, because early treatment gives the best chance of full recovery.

Question 3

Should I take a B12 supplement if I am vegan?

Accepted Answer

Most health bodies advise vegans to take B12 regularly, as a supplement or in fortified foods, because plant foods do not provide reliable amounts. Ask your clinician or pharmacist about the right dose.

Question 4

Is high B12 dangerous?

Accepted Answer

High B12 from supplements is usually harmless because extra is passed in urine. A high level without supplements is worth discussing with your clinician, as it can sometimes point to another condition.