What it means
Vitamin B12 is needed to make red blood cells and keep nerves healthy. People who lack intrinsic factor, the stomach protein needed to absorb B12 (pernicious anemia), or who have had stomach or bowel surgery, usually get it by injection or nasal spray for life. Others at risk of deficiency include strict vegans, older adults and people taking metformin or acid-lowering drugs for a long time.
For the nurse
Teach clients with pernicious anemia that treatment is lifelong even when they feel better. Watch the potassium level when treatment for severe deficiency begins, since it can drop as new red cells form.
At a glance
| Normal range | Vitamin B12 blood level about 200–900 pg/mL [148–664 pmol/L]; each lab sets its own range. |
|---|---|
| Drug class | vitamin (B12) |
| Brand names | Nascobal (nasal spray) |
| Spanish | cianocobalamina |
| Also written | Nascobal |
Related terms
anemia
A lower than normal number of red blood cells or amount of hemoglobin in the blood.
vitamin
A substance the body needs in small amounts for normal growth and function, mostly from food.
vitamin B12
A vitamin from animal foods that the body needs to make red blood cells and keep nerves healthy; also called cobalamin.
pg/mL
Picograms per milliliter: a unit for very small amounts of a substance in a fluid.