Pernicious anemia is caused by the deficiency of which vitamin?

Pernicious anemia is caused by the deficiency of which vitamin?

• A. Vitamin B12
• B. Vitamin D
• C. Vitamin C
• D. Vitamin A

Answer: (A)

Pernicious anemia is a type of megaloblastic anemia caused by a deficiency of vitamin B12, which is essential for red blood cell formation and DNA synthesis. In pernicious anemia, the body cannot absorb vitamin B12 properly because intrinsic factor, a protein needed for absorption in the gut, is lacking or dysfunctional. This impaired absorption leads to fewer healthy red blood cells and the characteristic large, immature cells seen in this condition. Vitamin B12 comes mainly from animal products, and its absorption depends on intrinsic factor produced in the stomach. When intrinsic factor is absent or defective, B12 can’t be absorbed even if dietary intake is adequate, leading to pernicious anemia. The other vitamins cause different problems. Deficiency of vitamin D leads to bone-related diseases like rickets or osteomalacia; vitamin C deficiency causes scurvy with gum disease and poor wound healing; vitamin A deficiency leads to vision problems such as night blindness.

Pernicious anemia is a type of megaloblastic anemia caused by a deficiency of vitamin B12, which is essential for red blood cell formation and DNA synthesis. In pernicious anemia, the body cannot absorb vitamin B12 properly because intrinsic factor, a protein needed for absorption in the gut, is lacking or dysfunctional. This impaired absorption leads to fewer healthy red blood cells and the characteristic large, immature cells seen in this condition.

Vitamin B12 comes mainly from animal products, and its absorption depends on intrinsic factor produced in the stomach. When intrinsic factor is absent or defective, B12 can’t be absorbed even if dietary intake is adequate, leading to pernicious anemia.

The other vitamins cause different problems. Deficiency of vitamin D leads to bone-related diseases like rickets or osteomalacia; vitamin C deficiency causes scurvy with gum disease and poor wound healing; vitamin A deficiency leads to vision problems such as night blindness.