Detrimental Impact of Interferon-Based Regimens for Chronic Hepatitis C on Vitamin D/Parathyroid Hormone Homeostasis

Livia Salmi1, *, Matteo Nazzareno Barbaglia1, Carlo Smirne1, 2, Sara Bianco1, 2, Giulia Guaschino1, 2, Maria Grazia Stella Crobu3, Rosalba Minisini1, Mario Pirisi1, 2
1 Department of Translational Medicine, Università del Piemonte Orientale UPO, Novara, Italy
2 Division of Internal Medicine, “AOU Maggiore della Carità”, Novara, Italy
3 Laboratory of Molecular Virology,“AOU Maggiore della Carità”, Novara, Italy

© 2018 Salmi et al.

open-access license: This is an open access article distributed under the terms of the Creative Commons Attribution 4.0 International Public License (CC-BY 4.0), a copy of which is available at: ( This license permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

* Address correspondence to this author at the Department of Translational Medicine, Università del Piemonte Orientale UPO, via Solaroli 17, Novara (NO), 28100, Italy; Tel: +3903213733690; E-mail:



Both the anti-infective and anti-inflammatory properties of vitamin D, an essential hormone of calcium homeostasis, have ample support in the literature. The high rates of vitamin D deficiency among patients with chronic hepatitis C are also well known. That supplementation with vitamin D may boost sustained viral response rates in vitamin D deficient, hepatitis C virus (HCV) infected patients undergoing Interferon-alpha (IFN) treatment, on the other hand, is controversial. Surprisingly, studies considering in this latter setting what are the effects of IFN treatment (with or without vitamin D supplementation) on the other major regulator of mineral metabolism, i.e. the Parathyroid hormone (PTH), are lacking.


Evaluate the impact of interferon-based treatment against HCV (±cholecalciferol supplementation) on vitamin D and PTH homeostasis.


A series of 40 consecutive patients received pegylated IFN plus ribavirin to treat chronic hepatitis C. At the discretion of their physician, some of them (N. = 27) received vitamin D supplementation while others did not (N. = 13). All had measured plasma 25-hydroxycholecalciferol and PTH concentrations at baseline, at completion of the 4th (TW4) and 12th treatment week (TW12) and at 24 weeks after the end of therapy (SVR24).


Plasma PTH concentration increased significantly from baseline during treatment, raising to 44.8 [30.7-57.2] pg/mL at TW4 (p=0.01), 47.0 [37.1-63.2] pg/mL at TW12 (p=0.006) to return to baseline levels in the follow-up (34.5 [27.6-43.0]; p=0.16). The proportion of patients who satisfied criteria for hyperparathyroidism was higher at TW12 (N=10, 25%) than at TW4 (N=6, 15%). There was no statistical correlation between vitamin D and PTH blood levels (ρ=-0.07; p=0.65).


An increase in plasma PTH occurs systematically during IFN treatment of HCV patients and cannot be prevented by vitamin D supplementation.

Keywords: INF, HCV therapy, Vitamin D supplementation, Secondary hyperparathyroidism, PTH, FGF23.