What is vitamin B12 and what does it do?
Vitamin B12 is a nutrient that helps keep the body’s nerve and blood cells healthy and helps make DNA, the genetic material in all cells. Vitamin B12 also helps prevent a type of anemia called megaloblastic anemia that makes people tired and weak.
Two steps are required for the body to absorb vitamin B12 from food. First, hydrochloric acid in the stomach separates vitamin B12 from the protein to which vitamin B12 is attached in food. After this, vitamin B12 combines with a protein made by the stomach called intrinsic factor and is absorbed by the body. Some people have pernicious anemia, a condition where they cannot make intrinsic factor. As a result, they have trouble absorbing vitamin B12 from all foods and dietary supplements.
How much vitamin B12 do I need?
The amount of vitamin B12 you need each day depends on your age. Average daily recommended amounts for different ages are listed below in micrograms (mcg):
|Life Stage||Recommended Amount|
|Birth to 6 months||0.4 mcg|
|Infants 7–12 months||0.5 mcg|
|Children 1–3 years||0.9 mcg|
|Children 4–8 years||1.2 mcg|
|Children 9–13 years||1.8 mcg|
|Teens 14–18 years||2.4 mcg|
|Pregnant teens and women||2.6 mcg|
|Breastfeeding teens and women||2.8 mcg|