Background: Vitamin D deficiency can cause many health problems and higher mortality. Chronic liver disease impairs vitamin D status by various mechanisms. The aim of our study was to estimate and directly compare vitamin D status in liver recipients before and within six months after LT to see whether there is an impact of restoration of proper liver function on 25(OH)D concentration.Patients and methods: Serum 25(OH)D concentration was determined and compared in the group of 110 adult patients before and within six months after LT. Measures performed right before transplantation were related to the etiology of liver disease, stage of cirrhosis and a season when the examination was done. 25(OH)D in the study group was also compared to the vitamin D concentration in the control group of 110 healthy persons matching the patients with respect to the age (p = 0.16), sex (p = 0.18) and body weight (p = 0.12). 25(OH)D concentration below 20 ng/mL was considered deficient, between 20 and 30 ng/ mL insufficient and > 30 ng/mL sufficient. Frequencies of some clinical episodes like fractures, infections, deaths and diabetes mellitus were compared between groups.Results: 25(OH)D concentration was significantly higher in the study group compared to the control group (20.83 + 13.48 vs. 14.8 + 8.39, p = 0.0001). There was a significant impact of summer-autumn season on better 25(OH)D concentration both in the study group and in the controls. The lowest concentration of vitamin D in the study group before LT was noted in alcoholic liver disease compared to the other etiologies (15.56 + 10.42 vs. 23.61 + 14.13, p = 0.002). The mean 25(OH)D concentration in the study group significantly improved after LT (27.37 + 12.5 vs. 20.83 + 13.48, p = 0.00001), but still more than 50% of recipients were significantly deficient. Conclusions:Vitamin D deficiency is ubiquitous. Liver insufficiency does not have much impact on vitamin D status. Patients with chronic liver disease as well as healthy subjects require regular vitamin D monitoring and supplementation when appropriate. Patients with alcoholic liver cirrhosis and the end-stage disease are in a special need. After LT concentration of vitamin D improves, but more than 50% of the recipients require either proper prophylaxis or treatment.