Most adults aim for 2.4 micrograms of vitamin B12 each day, with higher doses only when a health professional recommends them.

Short courses of higher dose vitamin B12 can ease shingles nerve pain when matched to your blood levels and used beside antiviral treatment.

For most healthy adults, about 2.4 micrograms of vitamin B12 per day meets daily needs, with slightly higher amounts in pregnancy and breastfeeding.

Most older adults do well with 2.4 micrograms of vitamin B12 plus a daily supplement of 10 to 100 micrograms, unless a clinician advises more.

Most adults need about 2.4 micrograms of vitamin B12 a day, with higher amounts in some life stages or medical situations.

Most adult women need about 2.4 micrograms of vitamin B12 a day, with pregnancy and breastfeeding raising that target slightly.

Most healthy vegetarians do well with a daily vitamin B12 supplement of 25–100 micrograms, or 1,000 micrograms taken twice each week.

Most adults on omeprazole do well with 250–500 mcg of vitamin B12 per day, unless their doctor advises a different dose based on tests.

Most adults with diabetes get enough vitamin B12 with 2.4–4 mcg daily, but higher doses or injections depend on lab test results.

Daily vitamin B12 needs vary by age; most adults need about 2.4 micrograms a day from food and supplements combined.