Inflammatory bowel disease (IBD) is an autoimmune disorder impacting the gastrointestinal system and can due to complicate Glucose-6-phosphate dehydrogenase (G6PD) deficiency; contracting malaria. cause iron deficiency anemia; chronic blood loss, and impaired iron absorption. megaloblastic anemia; a vegan diet. long COVID-19; mRNA vaccines. macrocytic anemia; iron overload. .