VITAMINS AND HIGH-DOSE CHEMOTHERAPY AND RADIOTHERAPY

Plasma from 22 patients was examined for alpha- and gamma-tocopherol (vitamin E), the carotinoids beta-carotene (provitamin A) and lycopene, retinol (vitamin A), and ascorbic acid (vitamin C) before, during and after conditioning chemotherapy for bone marrow transplantation, 18 of these received total body irradiation as well. In addition, alpha-tocopherol in red blood cell membranes was measured. Retinol and ascorbic acid have been applied in multiple of the recommended doses (Deutsche Gesellschaft fur Ernahrung and Recommended Dietary Allowance, respectively). The chosen doses were sufficient to maintain the initial plasma concentrations of these vitamins. However, alpha-tocopherol (in RDA doses) and beta-carotene (no RDA established) concentrations deteriorated after the conditioning therapy (20 and 50 % loss, respectively). The loss of these lipid-soluble antioxidants has been considered to result from lipid peroxidation. On the basis of the presented results we propose intervention studies to investigate the effect of high dose antioxidant administration on the toxicity (mainly of liver and lung) of intensive antineoplastic therapy protocols.