. "The chemical reactions and pathways involving reduced nicotinamide adenine dinucleotide (NADH), a coenzyme present in most living cells and derived from the B vitamin nicotinic acid." . . "NADH metabolic process" . "NAD (reduced) metabolic process" . "NAD (reduced) metabolism" . "NADH metabolism" . "reduced NAD metabolic process" . "reduced NAD metabolism" . "reduced nicotinamide adenine dinucleotide metabolic process" . "reduced nicotinamide adenine dinucleotide metabolism" . . . . .