which can be considered the real reasons for malnutrition
Malnutrition Undernourishment is most often due to not enough high-quality food being available to eat.[5] This is often related to high food prices and poverty.[1][5] A lack of breastfeeding may contribute, as may a number of infectious diseases such as: gastroenteritis, pneumonia, malaria, and measles, which increase nutrient requirements.[5] There are two main types of undernutrition: protein-energy malnutrition and dietary deficiencies.[12] Protein-energy malnutrition has two severe forms: marasmus (a lack of protein and calories) and kwashiorkor (a lack of just protein).[2] Common micronutrient deficiencies include: a lack of iron, iodine, and vitamin A.[2] During pregnancy, due to the body's increased need, deficiencies may become more common.[13] In some developing countries, overnutrition in the form of obesity is beginning to present within the same communities as undernutrition.[14] Other causes of malnutrition include anorexia nervosa and bariatric surgery.[15][16]
Parietal cell Parietal cells also produce intrinsic factor. Intrinsic factor is required for the absorption of vitamin B12 in the diet. A long-term deficiency in vitamin B12 can lead to megaloblastic anemia, characterized by large fragile erythrocytes. Pernicious anaemia results from autoimmune destruction of gastric parietal cells, precluding the synthesis of intrinsic factor and, by extension, absorption of Vitamin B12. Pernicious anemia also leads to megaloblastic anemia. Atrophic gastritis, particularly in the elderly, will cause an inability to absorb B12 and can lead to deficiencies such as decreased DNA synthesis and nucleotide metabolism in the bone marrow.