Aim: To evaluate the effects of vitamin D on transient elastography (TE, FibroScan) indices of liver steatosis (controlled attenuation parameter [CAP]) and fibrosis (liver stiffness measurement [LSM]) in adults with non-alcoholic fatty liver disease (NAFLD).
Patients and methods: In this randomized (2:1), double-blind, single-centre, 12-month trial, patients with NAFLD were treated with vitamin D (1000 IU/day) (n = 201) or a matching placebo (n = 110). Two co-primary outcomes were changes in CAP and LSM after 360 days of treatment versus baseline. Two main secondary outcomes were CAP/LSM changes after 180 days of treatment.
Results: Both CAP and LSM gradually decreased in vitamin D-treated patients and slightly increased in the placebo arm. Vitamin D was superior to placebo for both primary outcomes (mean differences in CAP and LSM changes (-49.5 dB/m [95% CI -59.5 to -39.4] and -0.72 kPa [95% CI -1.43 to 0.00], respectively) and both secondary outcomes (-22.1 dB/m [-32.1 to -12.1] and -0.89 kPa [-1.61 to -0.17], respectively). Of a number of exploratory outcomes (change at 12 months vs. baseline), vitamin D reduced serum uric acid (-17.9 μmol/L [-30.6 to -5.2]), gamma-glutamyltransferase (-8.9 IU/L [-15.5 to -2.3)] and fasting serum insulin levels (-5.1 pmol/L [-9.3 to -0.8]) as well as the homeostatic model assessment of insulin resistance index (-1.6 [-3.1 to -0.2]) (false discovery rate [5%]-adjusted P-values between .0572 and .0952).
Conclusion: Low-medium dose supplementation of vitamin D (1000 IU/day) over 12 months reduces TE indices of liver steatosis (CAP) and fibrosis (LSM) in NAFLD patients.
Keywords: elastography; non-alcoholic fatty liver disease; treatment; vitamin D.
© 2020 John Wiley & Sons Ltd.