Vanillyl mandelic acid
Vanillyl mandelic acid (VMA) is a metabolite of the catecholamine: norepinephrine.
VMA is found in the urine, along with other catecholamine metabolites, including homovanillic acid (HVA). In timed urine tests the quantity (concentration μg /24 h) is assessed, along with creatinine clearance, and the concentration of cortisols, catecholamines, and metanephrines.
These urinalysis tests are used to diagnose an adrenal gland tumor called pheochromocytoma, a tumor of catecholamine-secreting chromaffin cells. These tests may also be used to diagnose neuroblastomas, and to monitor treatment of these conditions.
Norepinephrine breaks down into normetanephrine and VMA. Norepinephrine is one of the hormones produced by the adrenal glands, which are found on top of the kidneys. They are released into the blood during times of physical or emotional stress, which are factors that may skew the results of the test.