General Info

Norman Clinical Laboratory, Inc. (NCL) provides a means to test individuals through the mail for cobalamin (vitamin B12 ) deficiency. The test measures methylmalonic acid (MMA) by selected ion monitoring isotope dilution gas chromatography mass spectrometry (GC/MS) in a random spot urine specimen. The MMA value is normalized to urine creatinine to correct for urine dilution. The urinary MMA/creatinine ratio (uMMA) test is more accurate than the blood test as it indicates tissue/cellular B12 deficiency.