NAD acts as a cofactor for all except

Niacin (Vitamin B3) in biologically active form of NAD+ (nicotinamide adenine dinucleotide) and NADP+ (nicotinamide, adenine dinucleotide phosphate) act as cofactor for various enzymes such as NADP+ Cofactor Glucose-6-phosphate dehydrogenase (G-6-PD (glucose-6-PO4 to 6-phosphogluconate) Glutathione reductase Either NADP+ or NAD+  Cofactor Glutamate dehydrogenase (glutamate → α-ketoglutarate + NH3) Isocitrate dehydrogenase (isocitrate → oxalosuccinate)  NAD+ Cofactor Malate dehydrogenase (malate → oxaloacetate) Alcohol dehydrogenase (ethanol → acetaldehyde Lactate dehydrogenase (pyruvic acid → lactic acid) Glyceraldehyde-3-phosphate dehydrogenase (glyceraldehyde 3P →1, 3 diphosphoglycerate) α - Glycero-P-dehydrogenase α -Ketoglutarate dehydrogenase (α – ketoglutarate → CoA) Pyruvate dehydrogenase complex (PDC) (pyruvate →  CoA)