Comparative study of vanillylmandelic acid in random and 24-hour urine collections.

Urinary vanillylmandelic acid (VMA) levels were determined in random samples and in 24-hour collections from 52 patients. Random sample levels were compared with levels in 24-hour collections and showed good correlation (r = 0.99), and no statistically significant differences was found when urinary VMA levels in random samples expressed in micrograms/mg creatinine (p greater than 0.1). Normal values of VMA in random urine samples of 226 healthy volunteers for different age groups of 1-5, 6-10, 11-15, 16-30, 31-60 years old were 17.03 +/- 6.61, 10.32 +/- 3.25, 10.87 +/- 4.5, 7.62 +/- 3.05 and 7.79 +/- 3.94 micrograms/mg of creatinine respectively.