VITAMIN B12 DEFICIENCY AS A CAUSE OF HEMATOLOGICAL ABNORMALITIES: DIAGNOSTIC AND THERAPEUTIC INSIGHTS

Abstract

Vitamin B12 is also called cobalamin and it is necessary for the synthesis of DNA, nuclear maturation, and hematopoiesis. Deficiency of this essential nutrient has been a global health concern in people with low dietary intake, malabsorption, and increased physiological requirements. This review aims to bring together the current information regarding the chemistry, dietary intake, absorption, metabolism, and etiology of vitamin B12 deficiency, particularly its impact on the hematological system. Deficiency of this nutrient affects DNA synthesis in proliferating hematopoietic precursor cells, leading to ineffective erythropoiesis, as manifested as hematological abnormalities. These abnormalities are macrocytic anemia, leucopenia, thrombocytopenia, and pancytopenia. Alterations in red cell parameters, white blood cell morphology, platelet counts, and peripheral blood smear results are critically discussed. The diagnostic approach by different parameters such as hematological parameters, levels of vitamin B12, and operating parameters such as methyl malonic acid and homocysteine is reviewed. The therapeutic approach by supplements of vitamin B12, which are administered in oral and parenteral forms, and their impact on hematological parameters are discussed. The public health implications and preventive measures are highlighted with the gaps in the research in vitamin B12 deficiency and associated hematological disorders, which emphasize the need for detection and prevention of the condition.