Hepatocellular carcinoma and vitamin D: a review

The non-classical actions of vitamin D, namely antiproliferation, pro-differentiation, pro-apoptosis, anti-inflammation, and immune regulation, have received great attention during the past decade. Increasing evidence from epidemiological studies showing the inverse association between vitamin D status and incidence of many forms of cancer as well as biochemical studies has suggested that vitamin D deficiency may play a role in the cause and progression of these types of cancer. Recently, vitamin D and its analogs have been deemed as potential regimen to treat a variety of cancers alone or in combination with other drugs. Although, the epidemiologic evidence regarding the association of vitamin D and hepatocellular carcinoma (HCC) is still inconclusive, biochemical evidence clearly indicates that HCC cells are responsive to the inhibitory effect of vitamin D and its analogs. In this review, we discuss the current status of HCC and its treatment, the source, metabolism, functions, and the mechanism of actions of vitamin D, and the biochemical studies of vitamin D analogs and their implications in the prevention and treatment of HCC.