Vitamin B12 (cyanocobalaminA)

Follow one of these dose regimens.
AgeUS RDA
(µg)
2 Doses per Day
(µg)
Daily Dose
(µg)
2 Doses per WeekB
(µg)
0 - 5 mos0.4n/an/a n/a
6 - 11 mos0.40.4 - 15 - 20 200
1 - 3 yrs0.90.8 - 1.510 - 40 375
4 - 8 yrs1.21 - 213 - 50 500
9 - 13 yrs1.81.5 - 2.520 - 75 750
14 - 64 yrs2.42 - 3.525 - 100 1000
65+ yrs2.6 - 500 - 1000 -
pregnancy2.62.5 - 425 - 100 1000
lactation2.82.5 - 430 - 100 1000
µg = mcg = microgram = 1/1,000 of a milligram (mg)

n/a - Not applicable. Infants should be receiving breast milk or commercial formula which contains the necessary amounts of vitamin B12.

There is a large difference between amounts taken twice daily and once daily because beyond 3 µg (for adults), absorption drops significantly.

Amounts much larger than these are considered safe, but it's probably best not to take more than twice the recommended amounts.

AThese recommendations are for cyanocobalamin only. There is not enough research on other forms of vitamin B12 to recommend specific dosages from supplements. For more information, see Alternatives to Cyanocobalamin: Methylcobalamin & Dibencozide.

BLarge doses of B12 can trigger acne-like symptoms in a small percentage of people.