Has glycerol-3-phosphate dehydrogenase activity. NAD(+) + sn-glycerol 3-phosphate = dihydroxyacetone phosphate + H(+) + NADH Inhibited by zinc ions and sulfate. Homodimer. Expressed in liver (at protein level). The disease is caused by variants affecting the gene represented in this entry. Belongs to the NAD-dependent glycerol-3-phosphate dehydrogenase family.