Fat-soluble vitamin deficiency remains a challenge in cystic fibrosis (CF), chronic pancreatitis, and biliary atresia. Liposomes and cyclodextrins can enhance their bioavailability, thus this multi-center randomized placebo-controlled trial compared three-month supplementation of fat-soluble vitamins in the form of liposomes or cyclodextrins to medium-chain triglycerides (MCT) in pancreatic-insufficient CF patients. The daily doses were as follows: 2000 IU of retinyl palmitate, 4000 IU of vitamin D3, 200 IU of RRR-α-tocopherol, and 200 µg of vitamin K2 as menaquinone-7, with vitamin E given in soybean oil instead of liposomes. All participants received 4 mg of β-carotene and 1.07 mg of vitamin K1 to ensure compliance with the guidelines. The primary outcome was the change from the baseline of all-trans-retinol and 25-hydroxyvitamin D3 concentrations and the percentage of undercarboxylated osteocalcin. Out of 75 randomized patients (n = 28 liposomes, n = 22 cyclodextrins, and n = 25 MCT), 67 completed the trial (89%; n = 26 liposomes, n = 18 cyclodextrins, and n = 23 MCT) and had a median age of 22 years (IQR 19-28), body mass index of 20.6 kg/m2 [18.4-22.0], and forced expiratory volume in 1 s of 65% (44-84%). The liposomal formulation of vitamin A was associated with the improved evolution of serum all-trans-retinol compared to the control (median +1.7 ng/mL (IQR -44.3-86.1) vs. -38.8 ng/mL (-71.2-6.8), p = 0.028). Cyclodextrins enhanced the bioavailability of vitamin D3 (+9.0 ng/mL (1.0-17.0) vs. +3.0 ng/mL (-4.0-7.0), p = 0.012) and vitamin E (+4.34 µg/mL (0.33-6.52) vs. -0.34 µg/mL (-1.71-2.15), p = 0.010). Liposomes may augment the bioavailability of vitamin A and cyclodextrins may strengthen the supplementation of vitamins D3 and E relative to MCT in pancreatic-insufficient CF but further studies are required to assess liposomal vitamin E (German Clinical Trial Register number DRKS00014295, funded from EU and Norsa Pharma).
Keywords: cholecalciferol; cyclodextrin; cystic fibrosis; liposome; menaquinone; retinol; tocopherol; vitamin A; vitamin D; vitamin E; vitamin K.