Randomized study comparing vitamin D3 and 1α-Hydroxyvitamin D3 in combination with pegylated interferon/ribavirin therapy for chronic hepatitis C.

Background and Aim: An intention-to-treat prospective randomized study was carried out to compare the potentiation of antiviral efficacies between cholecalciferol, non-activated vitamin D3 supplement, and alfacalcidol, activated 1α-Hydroxyvitamin D3 [1α (OH)-vitamin D3].
Methods: Chronic hepatitis patients with genotype 1b hepatitis C virus (HCV) infection showing serum HCV-RNA levels greater than 5 Log IU/mL received oral administration of cholecalciferol (2000 IU/day) or alfacalcidol (0.5 μg/day) for 4 weeks, and then they were given pegylated interferon (Peg-IFN)-α2a plus ribavirin therapy in combination with either vitamin D3 for 48 or 72 weeks according to the response-guided manner.
Results: A total of 36 patients were evaluated. Serum 25-hydroxyvitamin D3 [25(OH)-D3] levels were increased only in patients in the cholecalciferol group during the lead-in vitamin D administration, and the levels at 4 weeks were higher in these patients than in those in the alfacalcidol group (P < 0.001), while serum 1α,25-dihydroxyvitamin D3 [1α,25(OH)2 -D3] levels were not different between both groups. Rapid virological response was obtained in six (33%) patients in the cholecalciferol group; the ratio was higher than that in the alfacalcidol group (one patient; 6%, P < 0.05). Serum HCV-RNA level decline at 4 weeks of combined Peg-IFN-α2a plus ribavirin therapy compared with the baseline levels were greater in the cholecalciferol group (4.6 Log IU/mL) than in the alfacalcidol group (3.5 Log IU/mL) (P < 0.05), when four patients showing null response to the therapy was excluded. However, both complete early virological response and sustained viral response rates were not different between both groups.
Conclusion: Cholecalciferol produced superior potentiation of the antiviral activity than alfacalcidol only during the initial periods of combined Peg-IFN-α2a plus ribavirin therapy through upregulation of serum 25(OH)-D3 levels.
(© 2015 Journal of Gastroenterology and Hepatology Foundation and Wiley Publishing Asia Pty Ltd.)