Thursday Oct 24, 2013 (foodconsumer.org) -- Anew study in Hepatology finds evidence suggesting that taking -hydroxyvitamin D3 as a dietary supplement can suppress the production of hepatitis C viruses.

It has been known that vitamin D is important for innate immunity and it helps the production of antibacterial peptides that kill pathogenic bacteria and viruses.  Vitamin D Council has reported that older people who took vitamin D supplements were at a very low risk of contracting flu and bird-flu.

Earlier scientists have found that supplementation of vitamin D, usually D3, significantly improved sustained viral response to interferon-based therapy.  The current study led by T. Matsumura from Showa University School of Medicine in Tokyo, Japan and colleagues provides an explanation why vitamin D can help fight hepatitis C when patients were treated with an interferon based therapy.

Authors of the study found  "25-hydroxyvitamin D(3) [25(OH)D(3) ], but not vitamin D(3) or 1,25-dihydroxyvitamin D(3) , reduced the extra- and intracellular levels of HCV core antigen in a concentration-dependent manner." They further found that 25(OH)D(3) inhibits the production of hepatitis C viruses "at the level of infectious virus assembly, but not entry or replication."

The researchers concluded "25(OH)D(3) is a novel anti-HCV (hepatitis C virus) agent that targets an infectious viral particle assembly step. This finding provides insight into the improved efficacy of anti-HCV treatment via the combination of vitamin D(3) and IFN (interferon)."

25-hydroxyvitamin D3 is converted from vitamin D3 in the liver.  25(OH)D3 can be further metabolized in the kidneys to become 1,25-dihydroxyvitamin D3 or 1,25(OH)2D3.

There are two types of vitamin D, D3 produced in animals and D2 produced in mushroom.  They are similar, but not the same.  An authoritative vitamin D researcher Michael F. Holick at Boston University published a paper to suggest that vitamin D2 is as effective as vitamin D3.

Vitamin D deficiency is involved in more than 100 health conditions and in addition to the protective effect against bacteria and viruses, it can also protect against diseases like heart disease, type 2 diabetes and cancer among other diseases. (David LIu)