Active form of Vitamin D3 Inhibits Hepatitis C Virus among Liver Cells
Several studies have indicated that vitamin D3 inhibits hepatitis C virus infecting liver cells. Apparently this inhibition occurs most readily not from supplemented vitamin D – but with the metabolically active form and sun-derived form of vitamin D.
Researchers from Tokyo’s Showa University School of Medicine infected human liver cells with hepatitis C and found that 1,25-dihydroxyvitamin D(3) – the typical vitamin D3 used in supplements – did not reduce hepatitis antigens within the cells, while 25-hydroxyvitamin D(3) [25(OH)D(3)did accomplish a significant inhibition of the HCV virus.
The researchers stated:
“Our results also suggest that 25(OH)D(3), not vitamin D(3) , is a better therapeutic option in patients with hepatic dysfunction and reduced enzymatic activity for generation of 25(OH)D(3).”
This doesn’t meant that vitamin D3 supplementation isn’t therapeutic for HCV patients. It simply means that only the body’s metabolic version of D3 – calcitriol, which is more of a hormone than a vitamin – is the effective element.
And it is true that vitamin D3 supplementation will increase levels of 25(OH)D(3) in the blood, because the body can convert 1,25(OH)D(3) to 25(OH)D(3). The question, as has been raised by research that we investigated with another article – is whether supplemented vitamin D3 is the most effective form of vitamin D – and will it be sequestered – taken in – to fat cells to be utilized by the body’s cells as needed.
This is not the first study that has found calcitriol inhibits HCV
In 2011, research from Tel-Aviv University’s Sackler School of Medicine also found that vitamin D3 has potent antiviral properties that can suppress the Hepatitis C virus among human liver cells. The laboratory research, performed by University scientists and researchers from the Molecular Hepatology Research Laboratory and the Felsenstein Medical Research Center, found that Vitamin-D3 inhibits the replication of the hepatitis C virus within the liver.
The researchers found that the liver cells express a particular gene called CYP27B1. This gene is responsible for the enzyme that synthesizes calcitiol from vitamin D. It is the calcitriol that interferes with the hepatitis C virus by stimulating the interferon-beta pathway within the cells – which blocks the replication of the virus.
The research, led by Professor and Vice-Dean of the Sackler Medical School, Ran Tur-Kaspa, M.D., and leading viral researcher Meital Gal Tanamy, Ph.D., determined that the liver cells “contain the full machinery for vitamin-D metabolism and activity.”
This study also found that liver cells infected by hepatitis produce more calcitriol from the vitamin D. This relates to smart liver cells responding to an active infection.
The form of vitamin D found to have these anti-viral properties was D3, which is the type the body manufacturers from the sun.
While vitamin D3 supplements are available, the vitamin D3 molecule is naturally produced when ultraviolet-B in wavelengths of 270-290 nanometers enters our skin. Here a derivative of cholesterol called 7-dehydrocholesterol undergoes a electrocyclic reaction to produce a pre-vitamin D.
The pre-vitamin D molecule undergoes hydroxylation in the liver – as well as in the kidneys and in other tissues – to convert to calcitriol. As we exposed in the article mentioned above, the most sequestered form of this hormone is its sulfated form.
Matsumura T, Kato T, Sugiyama N, Tasaka-Fujita M, Murayama A, Masaki T, Wakita T, Imawari M. 25-Hydroxyvitamin D3 suppresses hepatitis C virus production. Hepatology. 2012 Oct;56(4):1231-9. doi: 10.1002/hep.25763.
Gal-Tanamy M, Bachmetov L, Ravid A, Koren R, Erman A, Tur-Kaspa R, Zemel R. Vitamin D: an innate antiviral agent suppressing hepatitis C virus in human hepatocytes. Hepatology. 2011 Nov;54(5):1570-9. doi: 10.1002/hep.24575.