EVALUATION OF THE RELATIVE DOSE-RESPONSE TEST FOR VITAMIN-A NUTRITURE IN CIRRHOTICS

The rise in serum vitamin A 5 h after a 450 .mu.g oral dose of the vitamin (retinyl palmitate) was used to assess vitamin A nutriture in patients with alcoholic cirrhosis. The test was carried out on 21 hospitalized male patients and 12 normal age and sex-matched control subjects. The relative dose response (RDR), expressed as percentage, was calculated as A5-A0/A5 .times. 100 where A0 = the fasting serum retinol level and A5 = the serum retinol 5 h postdosing. Vitamin A-deficient patients (those with serum retinol levels < 30 .mu.g/dl and an abnormal dark adaptation test or RDR .gtoreq. 14%) were treated with 4 wk of oral vitamin A (10,000 .mu.g/day), then repeat RDR and dark adaptation tests were carried out. Among 8 cirrhotics with abnormal dark adaptation, the mean .+-. SEM (SE of mean) RDR was 21 .+-. 9 vs. 3 .+-. 3% in patients with normal dark adaptation (P < 0.01). RDR tests of patients with normal dark adaptation did not differ from those of 12 normal age and sex-matched control subjects (normal RDR response 0 to 14%). Among patients with vitamin A-deficiency treatment with vitamin A resulted in the mean .+-. SEM RDR declining from 21 .+-. 9 to 5 .+-. 2%. This fall failed to reach statistical significance (P = 0.06). The RDR test appears to be useful as a predictor of vitamin A deficiency, even among patients with far advanced hepatic disease.