The amount of a glycerol-3-phosphate dehydrogenase [NAD(+)], cytoplasmic when measured in blood. The trait is Ontology of Biological Attributes entry OBA_2051451 (level of glycerol-3-phosphate dehydrogenase [NAD(+)], cytoplasmic in blood). Also known as: blood glycerol-3-phosphate dehydrogenase [NAD(+)], cytoplasmic amount.