What is the most effective after care diet regime for a prognosis of pancytopenia?

Depends on diagnosis: Pancytopenia is a descriptive diagnosis, that says a patient has low levels of red cells, white cell, and platelets. It doesn't indicate the cause, which can include leukemia, nutritional deficiency, aplastic anemia, other bone marrow cancers, myelodysplastic syndromes, ... It is a long list, and it is usually not something for which a particular diet is recommended, but it can be.

None known: Pancytopenia is not a diagnosis, it is a problem that needs evaluation to determine a cause. There is no specific diet that can help pancytopenia unless it is due to nutritional issues. Rarely vit B12 deficiency can lead to pancytopenia-b12 will thus help. Alcoholism can lead to pancytopenia-abstinence can help. A disease called myelodysplasia can lead to pancytopenia, and, rarely, b6 can help.