the recommended dietary allowance (rda) is 2. 4 micrograms per day for adults and adolescents aged 14 years and older. because 10%-30% of older people do not absorb food-bound vitamin b12 efficiently those over 50 years of age should meet the rda by eating foods fortified with b12 or by taking a vitamin b12 supplement. supplementation of 25-100 micrograms per day has been used to maintain vitamin b12 levels in older people. remember to include this on your personal medication list and always advise your health care providers and pharmacists of any vitamins supplements or herbals that you are taking.
what is the recommended dose for vitamin b12?