IMMUNOLOGY

Detailed explanation-1: -Pernicious anemia is a relatively rare autoimmune disorder that causes diminishment in dietary vitamin B12 (cobalamin) absorption, resulting in B12 deficiency and subsequent megaloblastic anemia. It affects people of all ages worldwide, particularly those over 60.

Detailed explanation-2: -Vitamin B12–deficiency anemia, also known as cobalamin deficiency, is a condition that develops when your body can’t make enough healthy red blood cells because it doesn’t have enough vitamin B12. Your body needs vitamin B12 to make healthy red blood cells, white blood cells, and platelets.

Detailed explanation-3: -Pernicious anemia is a type of vitamin B12 anemia. The body needs vitamin B12 to make red blood cells. You get this vitamin from eating foods such as meat, poultry, shellfish, eggs, and dairy products. A special protein, called intrinsic factor (IF), binds vitamin B12 so that it can be absorbed in the intestines.

Detailed explanation-4: -Vitamin B12 deficiency due to lack of intrinsic factor causes a type of anemia called pernicious anemia. Among older people, absorption may be inadequate because stomach acidity is decreased. Decreased stomach acidity reduces the body’s ability to remove vitamin B12 from the protein in meat.

Detailed explanation-5: -Pernicious anemia is a rare condition. It occurs in 0.1 percent of the general population and 1.9 percent in people who are older than 60 years, according to a 2012 study in the Journal of Blood Medicine.