Understanding Pernicious Anaemia and Vitamin Deficiency

Pernicious anaemia is a type of anaemia, which is a condition characterized by a lower-than-normal number of red blood cells or a reduced amount of haemoglobin in the red blood cells. These are essential for carrying oxygen throughout the body. Pernicious anaemia is specifically linked to a deficiency in a particular vitamin.

Which Vitamin Deficiency Causes Pernicious Anaemia?

The question asks which vitamin deficiency leads to pernicious anaemia. Let's examine the options provided:

• Vitamin K: This vitamin is primarily known for its role in blood clotting. Deficiency can lead to bleeding disorders, not typically pernicious anaemia.
• Vitamin E: This is an antioxidant vitamin. Deficiency is rare and can sometimes affect nerve function or cause certain types of anaemia in specific conditions, but not typically pernicious anaemia.
• Vitamin B₁₂: Also known as cobalamin, Vitamin B₁₂ is crucial for nerve function, DNA synthesis, and the formation of healthy red blood cells. A deficiency in Vitamin B₁₂ can lead to megaloblastic anaemia, a form of anaemia where red blood cells are abnormally large. Pernicious anaemia is a specific cause of Vitamin B₁₂ deficiency, often due to the body's inability to absorb enough Vitamin B₁₂ from the digestive tract, usually because of a lack of intrinsic factor. This deficiency directly impacts the production of red blood cells, causing the condition known as pernicious anaemia.
• Vitamin B₆: Also known as pyridoxine, Vitamin B₆ is involved in many metabolic processes, including haemoglobin synthesis. Deficiency can lead to certain types of anaemia (sideroblastic anaemia), but not pernicious anaemia.

Based on the functions of these vitamins and the specific nature of pernicious anaemia, the deficiency of Vitamin B₁₂ is the direct cause of this condition.

Importance of Vitamin B₁₂

Vitamin B₁₂ is vital for several bodily functions. Its role in the maturation of red blood cells is critical. Without enough Vitamin B₁₂, the bone marrow produces large, immature, and dysfunctional red blood cells, characteristic of megaloblastic anaemia, of which pernicious anaemia is a key type.

Therefore, a deficiency in Vitamin B₁₂ is the cause of pernicious anaemia.