Daily Vitamin B12 Intake Calculator
NIH-recommended daily vitamin B12 intake by age and pregnancy or breastfeeding status.
A general population guideline (NIH RDA), not medical advice — vitamin B12 deficiency is common in older adults and strict vegans/vegetarians, who may need supplementation beyond this baseline.
Recommended daily vitamin B12
2.4 mcg
NIH RDA guideline
For informational and educational purposes only — not medical advice, and not a substitute for consulting a qualified professional about your specific situation. TrueMeasureKit is not liable for decisions made based on these results. See our Terms of Service.
Why the requirement doesn't differ by sex
Unlike iron or many other nutrients, vitamin B12's RDA is set the same for men and women at every age — the NIH's guidance scales it by age and by pregnancy or breastfeeding status only. B12 is found almost exclusively in animal products (meat, fish, dairy, eggs), so people following a vegan diet, or older adults whose bodies absorb it less efficiently, are the groups most likely to fall short of this target through diet alone.
Frequently asked questions
Who is most at risk of low B12 intake?
Vegans and vegetarians are at higher risk since B12 occurs naturally almost exclusively in animal products, as are older adults (absorption naturally declines with age) and people on certain medications — fortified foods or supplements are common ways to close the gap.