Catalyzes the NAD(+)-dependent oxidation of formate to carbon dioxide. Involved in the cell stress response. formate + NAD(+) = CO2 + NADH Optimum pH is 6-8. Homodimer. By one-carbon metabolites, such as methanol, formaldehyde, and formate (at protein level) (Ref.3). Strongest induced by formaldehyde (PubMed:16232936). Belongs to the D-isomer specific 2-hydroxyacid dehydrogenase family. FDH subfamily.