<prompt> Which vitamin is required for glucose 6 phosphate dehydrogenase?RiboflavinThiamineNiacinBiotin  <response>: Niacin - pyridine derivative. Coenzyme forms - NADP, NAD The coenzymes NAD and NADP are involved in a variety of oxidation-reduction reactions Selected example of NAD NADP dependent enzyme NAD Enzyme Coenzyme Isocitrate dehydrogenase NAD a- Ketoglutarate dehydrogenase NAD Glucose 6-phosphate dehydrogenase NADP Malate dehydrogenase NAD Glutamate dehydrogenase NAD Glyceraldehyde 3-phosphate dehydrogenase NAD or NADP Lactate dehydrogenase NAD Alcohol dehydrogenase NAD NOTE: Niacin causes hyperglycemia. Niacin induces pancreatic islet dysfunction through activation of the islet beta-cell G-coupled protein receptors that mediate peroxisome proliferation and increase reactive oxygen species. It also decreases glucose-stimulated insulin secretion. Thus, it increases the blood glucose level and is contraindicated in diabetics. 