Final answer:
Pernicious anemia is true to be caused by a lack of vitamin B12 absorption due to insufficient intrinsic factor, often tied to an autoimmune condition. Dietary changes alone typically cannot correct it if the cause is related to absorption issues.
Step-by-step explanation:
Pernicious anemia is a specific form of anemia caused by the body's inability to absorb vitamin B12 from the gastrointestinal tract. It is true that pernicious anemia is caused by a lack of vitamin B12, which can be due to the body's failure to produce enough intrinsic factor, a protein that allows the vitamin to be absorbed in the intestine. This condition is often linked to an autoimmune disease where the body’s immune system attacks its own tissues, in this case, the stomach cells that produce intrinsic factor. Changing the diet to include more animal proteins may help somewhat for general vitamin B12 deficiency, but if the cause is due to an autoimmune response or due to surgery that removed parts of the stomach or intestines, increasing dietary intake alone won't overcome pernicious anemia because the problem is absorption, not intake. Lastly, pernicious anemia does not stimulate the production of intrinsic factor; in many cases, it is the lack of intrinsic factor that leads to the condition.