Vitamin B12: how much you need & why it matters
Red-cell formation, nerve myelination, DNA synthesis.
How much a day (adults)
| NIH (US) RDA | 2.4 |
| ICMR-NIN (India) — men | 2.2 |
| ICMR-NIN (India) — women | 2.2 |
India note: relevant to largely-vegetarian Indian diets — deficiency common
If you don't get enough
Associated deficiency: Vitamin B12 deficiency (pernicious anemia).
Reported signs of running low:
- Megaloblastic anemia
- Peripheral neuropathy
- Glossitis
- Cognitive impairment
These signs have many causes other than vitamin b12, and several are common in pregnancy anyway. They are a reason to ask for a blood test, not to self-diagnose or start a supplement.
Food sources
- Meat
- Fish
- Eggs
- Dairy
- Fortified foods
Named by the NIH Office of Dietary Supplements. Being a good source does not make a food right for pregnancy — check food safety in pregnancy too; liver, for one, is rich in several nutrients and generally advised against.
In pregnancy specifically
Requirements and reasons change during pregnancy. See vitamin b12 in pregnancy — why it matters, and the weeks it matters most.
Before you act on this
Educational reference; RDA/AI are population averages for healthy adults (needs differ by age, sex, pregnancy, and condition). Diagnose/treat deficiency only with a clinician.
Sources: NIH Office of Dietary Supplements (ODS) fact sheets / IOM Dietary Reference Intakes; ICMR-NIN (Nutrient Requirements for Indians).
Educational reference, not medical or dietary advice. RDAs are population averages for healthy adults — needs differ in pregnancy and breastfeeding. Ask your doctor or dietitian.