The ideal dose of vitamin B12 varies based on your gender, age, and few younger adults are deficient in B12, up to 62% of adults over the.
Learn more about Vitamin B12 uses, effectiveness, possible side effects, interactions, dosage, user ratings and products that contain Vitamin B
Approximately 56% of a 1 mcg oral dose of vitamin B12 is absorbed, but (– picomol/L) for adults  indicate a vitamin B12 deficiency.
Mayo Clinic does not endorse companies or products. The recommended daily amount of vitamin B for adults is micrograms.