Intrinsic Factor

Definition

Intrinsic factor is a glycoprotein secreted by the parietal cells in the stomach. It is essential for the absorption of vitamin B12 (cobalamin) from the diet in the small intestine.

5 Must Know Facts For Your Next Test

1. Intrinsic factor binds to vitamin B12 in the stomach, forming a complex that is then absorbed in the terminal ileum of the small intestine.
2. Without intrinsic factor, vitamin B12 cannot be properly absorbed, leading to a deficiency that can cause pernicious anemia.
3. Parietal cell damage, as seen in autoimmune gastritis or atrophic gastritis, can lead to a decrease in intrinsic factor production and subsequent vitamin B12 malabsorption.
4. Certain medications, such as proton pump inhibitors and H2 receptor antagonists, can also reduce intrinsic factor secretion and impair vitamin B12 absorption.
5. Intrinsic factor plays a crucial role in maintaining normal red blood cell production, nerve function, and DNA synthesis in the body.

Review Questions

• Explain the role of intrinsic factor in the absorption of vitamin B12.
  • Intrinsic factor, secreted by the parietal cells in the stomach, is essential for the absorption of vitamin B12 (cobalamin) from the diet. It binds to vitamin B12 in the stomach, forming a complex that can then be absorbed in the terminal ileum of the small intestine. Without intrinsic factor, vitamin B12 cannot be properly absorbed, leading to a deficiency that can cause pernicious anemia.
• Describe the potential causes of intrinsic factor deficiency and its consequences.
  • Intrinsic factor deficiency can occur due to parietal cell damage, as seen in autoimmune gastritis or atrophic gastritis, which can lead to a decrease in intrinsic factor production. Certain medications, such as proton pump inhibitors and H2 receptor antagonists, can also reduce intrinsic factor secretion and impair vitamin B12 absorption. The resulting vitamin B12 deficiency can lead to various health issues, including pernicious anemia, neurological problems, and DNA synthesis disorders.
• Analyze the importance of intrinsic factor in maintaining overall health and body function.
  • Intrinsic factor plays a crucial role in maintaining normal red blood cell production, nerve function, and DNA synthesis in the body. By facilitating the absorption of vitamin B12, intrinsic factor ensures that the body has sufficient levels of this essential nutrient. Vitamin B12 deficiency, caused by intrinsic factor deficiency, can lead to serious health consequences, such as pernicious anemia, neurological disorders, and impaired cellular function. Therefore, the proper secretion and function of intrinsic factor is vital for maintaining overall health and preventing vitamin B12-related diseases.

Related terms

Parietal Cells:

Specialized cells found in the lining of the stomach that secrete hydrochloric acid and intrinsic factor.

Vitamin B12: Also known as cobalamin, it is an essential vitamin required for red blood cell formation, neurological function, and DNA synthesis.

Malabsorption:

A condition where the body is unable to properly absorb nutrients from the digestive system.