Vitamin B12

Definition

Vitamin B12, also known as cobalamin, is a water-soluble vitamin essential for red blood cell formation, neurological function, and DNA synthesis. It is naturally found in animal products and can be taken as a supplement.

5 Must Know Facts For Your Next Test

1. Vitamin B12 deficiency can lead to megaloblastic anemia, characterized by the production of abnormally large red blood cells.
2. It plays a crucial role in maintaining the myelin sheath that surrounds and protects nerve fibers.
3. Absorption of Vitamin B12 occurs in the ileum of the small intestine and requires intrinsic factor, a protein produced by stomach lining cells.
4. Symptoms of deficiency include fatigue, weakness, constipation, loss of appetite, and neurological issues such as numbness and tingling in hands and feet.
5. Populations at risk for Vitamin B12 deficiency include older adults, vegetarians/vegans, and individuals with gastrointestinal disorders affecting absorption.

Review Questions

• What are the primary functions of Vitamin B12 in the body?
• Which population groups are most at risk for Vitamin B12 deficiency?
• How does the body absorb Vitamin B12 from food sources?

Related terms

Intrinsic Factor:

A glycoprotein necessary for the absorption of Vitamin B12 in the small intestine.

Megaloblastic Anemia:

A condition where bone marrow produces unusually large and structurally abnormal red blood cells due to Vitamin B12 or folate deficiency.

Myelin Sheath: The protective covering surrounding nerve fibers that is maintained by adequate levels of Vitamin B12.