Catalyzes the NAD(+)-dependent oxidation of formate to carbon dioxide. Formate oxidation is the final step in the methanol oxidation pathway in methylotrophic microorganisms (PubMed:9178506, PubMed:12144528, PubMed:11921099). Has a role in the detoxification of exogenous formate in non-methylotrophic organisms (PubMed:11921099). formate + NAD(+) = CO2 + NADH kcat is 6.5 sec(-1) with NAD(+) as substrate. Homodimer. Induced by formate. Belongs to the D-isomer specific 2-hydroxyacid dehydrogenase family. FDH subfamily.