Tutor et al.: Urinary Z)-glucaric acid in porphyria cutanea tarda 855 Summary: Twenty patients with porphyria cutanea tarda who had ingested no alcohol for at least 10 days before sampling were found to possess urinary Z>-glucaric acid levels similar to those of 30 clinically healthy controls. Correlation between urinary excretion of D-glucaric acid on the one band and plasma or urinary porphyrin concentrations on the other was not statistically significant. These results suggest that the high urinary concentrations of Z>-glucaric acid found in porphyria cutanea tarda patients by Budillon et al. (Acta Hepato-Gastroenterol. 25 (1978) 267) may have been due to recpnt consumption of alcohol rather than to the porphyrin pathology.