One review recommended that those with vitamin B12 deficiency take 1 mg of vitamin B12 daily for a month, followed by a maintenance dose of 125–250 mcg per day (21 Trusted Source).

Dear I.F.: The DV (a replacement for what we used to call the recommended daily allowance, or RDA) for vitamin B12 is 2.4 mcg. (There are 1,000 micrograms in a milligram, so 2.4 mcg is a very small ...

Medically reviewed by Jonathan Purtell, RDN Vitamin B12 helps your body make red blood cells, produce energy, and keep your ...

Males over 50 years who cannot get enough nutrients from their diet may benefit from taking a multivitamin. This article looks at the best options for different needs and budgets.

Dr. Roach: I am 73, and I was worried about dementia. Turns out, I am “normal.” However, the neurologist told me to take 2,000 mcg of B12 daily. My multivitamin has 100 mcg, which is 4,167% of ...