<prompt> The need for vitamin B12 and folic acid inthe formation of red blood cells is related primarily of their effects on:Synthesis and release of erythropoietin from the kidneyAbsorption of iron from the gutDNA synthesis in bone marrowHemoglobin formation in the red blood cell  <response>: Within 6-9 hours of treatment with vitamin B12 formation of nuclear DNA component promotes normoblastic reaction of the bone marrow. Folic acid also promotes the formation of nucleic acids. 