Catalyzes the NADH-dependent reduction of the oxo group at C3 of 3-dehydro-D-glucosides leading to D-glucosides. Probably functions in a metabolic pathway that transforms D-gulosides to D-glucosides. Can use 3-dehydro-D-glucose, methyl alpha-3-dehydro-D-glucoside and methyl beta-3-dehydro-D-glucoside as substrates in vitro. However, the actual specific physiological substrates for this metabolic pathway are unknown. To a lesser extent, is also able to catalyze the reverse reactions, i.e. the NAD(+)-dependent oxidation of the hydroxyl group at C3 of D-glucosides leading to 3-dehydro-D-glucosides. Cannot act on UDP-glucose, UDP-N-acetyl-D-glucosamine, D-glucosamine, N-acetyl-D-glucosamine, or UDP-D-galactose. a D-glucoside + NAD(+) = a 3-dehydro-D-glucoside + H(+) + NADH kcat is 0.65 sec(-1) for the NAD(+)-dependent oxidation of D-glucose (at pH 8.0 and 30 degrees Celsius). kcat is 1.14 sec(-1) for the NAD(+)-dependent oxidation of D-glucose (at pH 9.0 and 30 degrees Celsius). kcat is 0.58 sec(-1) for the NAD(+)-dependent oxidation of methyl alpha-D-glucoside (at pH 8.0 and 30 degrees Celsius). kcat is 1.2 sec(-1) for the NAD(+)-dependent oxidation of methyl alpha-D-glucoside (at pH 9.0 and 30 degrees Celsius). kcat is 0.4 sec(-1) for the NAD(+)-dependent oxidation of methyl beta-D-glucoside (at pH 8.0 and 30 degrees Celsius). kcat is 0.3 sec(-1) for the NAD(+)-dependent oxidation of methyl beta-D-glucoside (at pH 9.0 and 30 degrees Celsius). kcat is 0.17 sec(-1) for the NAD(+)-dependent oxidation of 1,5-anhydro-D-glucitol (at pH 8.0 and 30 degrees Celsius). kcat is 0.4 sec(-1) for the NAD(+)-dependent oxidation of 1,5-anhydro-D-glucitol (at pH 9.0 and 30 degrees Celsius). kcat is 4.7 sec(-1) for the NADH-dependent reduction of 3-dehydro-D-glucose (at pH 6.5 and 30 degrees Celsius). kcat is 22 sec(-1) for the NADH-dependent reduction of methyl alpha-3-dehydro-D-glucoside (at pH 7.0 and 30 degrees Celsius). kcat is 18 sec(-1) for the NADH-dependent reduction of methyl alpha-3-dehydro-D-glucoside (at pH 8.0 and 30 degrees Celsius). kcat is 19 sec(-1) for the NADH-dependent reduction of methyl beta-3-dehydro-D-glucoside (at pH 7.0 and 30 degrees Celsius). kcat is 12.5 sec(-1) for the NADH-dependent reduction of methyl beta-3-dehydro-D-glucoside (at pH 8.0 and 30 degrees Celsius). Belongs to the Gfo/Idh/MocA family.