For low vitamin B12, the right treatment depends on the cause of the deficiency. If it is due to a dietary gap (common in vegetarians or vegans), daily oral Vitamin B12 supplements, such as Methylcobalamin or Cyanocobalamin (usually 1000 mcg), are highly effective. However, if your body has trouble absorbing B12 due to gut issues or pernicious anemia, you will likely need prescription Vitamin B12 injections. Please consult your doctor so they can evaluate your specific cause and prescribe the correct form and dosage for you.