Vitamin D deficiency in hepatitis C virus infection: what is old? what is new?

Abstract

In the past few years, a growing body of clinical evidence has highlighted the risk of vitamin D deficiency in patients with chronic hepatitis C and that vitamin D levels are associated with the course of hepatitis C virus (HCV) infection, adverse effects, and treatment response to peginterferon/ribavirin. Recently, studies have found that vitamin D status is related to drug resistance and increased risk of infection in patients with liver cirrhosis. Vitamin D-related gene polymorphisms have been found to explain the interactions between vitamin D deficiency and HCV infection, offering a new perspective toward understanding the current problems such as the development of insulin resistance and racial differences in sustained virological response. Studies have been conducted to determine whether vitamin D supplementation as an adjuvant yields a better result compared with traditional HCV treatment. Here, we provide a brief review of the past and present knowledge of vitamin D in HCV infection.

Host genetic factors and clinical parameters influencing the occult hepatitis C virus infection in patients on chronic hemodialysis: Is it still a controversial infection?

“…Such a relationship was not observed in any other study, but others indicated that 25-hydroxyvitamin D deficiency seems to be common in patients with CHC and could be correlated with lower likelihood of achieving SVR, as well as more advanced stages of fibrosis, and augmented necroinflammation severity. [23][24][25] However, it seems that 25-hydroxyvitamin D deficiency might play an important role OCI incidence.…”

A Review of the Potential Benefits of Increasing Vitamin D Status in Mongolian Adults through Food Fortification and Vitamin D Supplementation

“…The seroprevalence of hepatitis B virus (HBV) and HCV in the general population in Mongolia is high (11.8% and 15%, respectively [81]). Modest evidence also exists to indicate that vitamin D supplementation in combination with Peg-interferon α injection and oral ribavirin improves sustained virus clearance for HCV genotype 1 but not genotypes 2–4 [82,83]. A study in Spain involving mostly HCV genotype 1 patients reported a higher rate of rapid viral response (23.5% vs. 16.1%; p = 0.005) and in the reduction of viral load to ≤15 (51.0% vs. 38.6%; p ≤ 0.001) for patients starting treatment with peginterferon–ribavirin in the sunnier half of the year than in the darker half of the year [84], suggesting that maintaining vitamin D repletion could prove to be a useful adjunctive measure in treating HCV.…”

The Role of Micronutrients in the Infection and Subsequent Response to Hepatitis C Virus

“…Vitamin D is a secosteroid hormone that plays a key role in calcium and bone homeostasis [145]. Vitamin D 3 (VD 3 ) is synthesized in the skin from 7-dehydrocholesterol, a process which depends on sunlight [146]. VD 3 is then converted in the liver to 25-dihydroxyvitamin D 3 (25(OH)VD 3 ) which is metabolized in the kidneys to 1,25(OH) 2 VD 3 , the most physiologically active VD 3 metabolite [145,146,147,148].…”

“…Recently, evidence has emerged that vitamin D has anti-fibrotic, anti-inflammatory and immunomodulatory properties. More specifically, it inhibits T cell proliferation, expression of interleukin-2, expression of IFN-γ and CD8 T-lymphocyte-mediated cytotoxicity [146]. These extra-skeletal effects are relevant in the pathogenesis and treatment of many causes of chronic liver disease [147,149].…”