Effect of clinical condition and mycophenolate mofetil on plasma retinol, α-tocopherol and β-carotene in renal transplant recipients

Introduction: Plasma antioxidant vitamins (retinol, alpha-tocopherol, beta-carotene) were measured to establish the influence of clinical condition and mycophenolate mofetil (MMF) treatment on the nutritional status of renal transplant recipients. Material and methods: In 106 adult patients plasma vitamins were measured and 24-h diet history questionnaires were conducted. The MMF influence on plasma vitamins was verified in 61 patients. Results: The current dietary intakes of vitamins in daily food rations were lower than recommended. Plasma retinol was lower in patients suffering from gastrointestinal disorders (1.25 +/- 0.48 mg/l vs. 1.55 +/- 0.70 mg/l) and inversely associated with aminotransferases activity (p = 0.019) and creatinine clearance (p = 0.021). Retinol concentrations were positively associated with plasma creatinine (p = 0.027) and pharmacokinetic parameters of MMF phenyl glucuronide. beta-Carotene concentrations were higher in women (0.39 +/- 0.46 mg/l vs. 0.28 +/- 0.23 mg/l; p = 0.041) and when MMF was co-administered with cyclosporine vs. tacrolimus (0.45 +/- 0.62 mg/l vs. 0.25 +/- 0.19 mg/l). Plasma alpha-tocopherol correlated negatively with the mycophenolic acid pre-dose concentration (p = 0.027) and was significantly lower in patients treated with calcineurin inhibitors (8.90 +/- 5.23 mg/l vs. 12.25 +/- 5.62 mg/l). A positive correlation was observed between alpha-tocopherol levels and aspartate aminotransferase (p = 0.006). In multivariate regression aspartate aminotransferase and MMF treatment significantly influenced retinol (p < 0.001). Conclusions: The MMF treatment was associated with significantly lower retinol concentrations. The gastrointestinal disorders occurrence in MMF-treated patients may cause a decrease in retinol absorption. Diet adjustment and/or vitamin A supplementation should be considered.