Pernicious anemia primarily results from a deficiency of which vitamin?

Pernicious anemia is primarily caused by a deficiency of vitamin B12. This condition occurs when there is an insufficient absorption of vitamin B12 in the body, typically due to a lack of intrinsic factor, a protein produced by the stomach that is necessary for the absorption of this vitamin. Vitamin B12 plays a crucial role in red blood cell formation and neurological function. Without adequate levels of vitamin B12, the body cannot produce healthy red blood cells, which leads to the characteristic symptoms of anemia as well as potential neurological issues.

The other vitamins listed—Vitamin C, Vitamin B6, and Vitamin D—do not primarily cause pernicious anemia. Vitamin C is important for immune function and skin health; Vitamin B6 is involved in various metabolic processes, including protein metabolism; and Vitamin D is crucial for bone health and regulating calcium levels. While deficiencies in these vitamins can lead to various health issues, they are not responsible for pernicious anemia specifically, which is distinctly linked to vitamin B12 deficiency.