NAD(+) + sn-glycerol 3-phosphate = dihydroxyacetone phosphate + H(+) + NADH NADP(+) + sn-glycerol 3-phosphate = dihydroxyacetone phosphate + H(+) + NADPH Membrane lipid metabolism; glycerophospholipid metabolism. Belongs to the NAD-dependent glycerol-3-phosphate dehydrogenase family.