Vitamin D in cutaneous carcinogenesis Part II
ABSTRACT Skin cancer is the most common cancer in the United States. Exposure to ultraviolet radiation is a known risk factor for skin cancer but is also the principal means by which the body obtains vitamin D. Several studies have suggested that vitamin D plays a protective role in a variety of internal malignancies. With regard to skin cancer, epidemiologic and laboratory studies suggest that vitamin D and its metabolites may have a similar protective effect. These noncalcemic actions of vitamin D have called into question whether the current recommended intake of vitamin D is too low for optimal health and cancer prevention. Part I will review the role of vitamin D in the epidermis; part II will review the role of vitamin D in keratinocyte-derived tumors to help frame the discussion on the possible role of vitamin D in the prevention of skin cancer.
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ABSTRACT: Vitamin D is formed mainly in the skin upon exposure to sunlight and can as well be taken orally with food or through supplements. While sun exposure is a known risk factor for skin cancer development, vitamin D exerts anti-proliferative and pro-apoptotic effects on melanocytes and keratinocytes in vitro. To clarify the role of vitamin D in skin carcinogenesis, we performed a review of the literature and meta-analysis to evaluate the association of vitamin D serum levels and dietary intake with cutaneous melanoma (CM) and non-melanoma skin cancer (NMSC) risk and melanoma prognostic factors. Twenty papers were included for an overall 1420 CM and 2317 NMSC. The summary relative risks (SRRs) from random effects models for the association of highest versus lowest vitamin D serum levels was 1.46 (95% confidence interval (CI) 0.60-3.53) and 1.64 (95% CI 1.02-2.65) for CM and NMSC, respectively. The SRR for the highest versus lowest quintile of vitamin D intake was 0.86 (95% CI 0.63-1.13) for CM and 1.03 (95% CI 0.95-1.13) for NMSC. Data were suggestive of an inverse association between vitamin D blood levels and CM thickness at diagnosis. Further research is needed to investigate the effect of vitamin D on skin cancer risk in populations with different exposure to sunlight and dietary habits, and to evaluate whether vitamin D supplementation is effective in improving CM survival.European journal of cancer (Oxford, England: 1990) 07/2014; 50(15). DOI:10.1016/j.ejca.2014.06.024 · 4.82 Impact Factor
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ABSTRACT: Most anti-cancer drugs are derived from natural resources such as marine, microbial and botanical sources. Cutaneous malignant melanoma is the most aggressive form of skin cancer, with a high mortality rate. Various treatments for malignant melanoma are available, but due to the development of multi-drug resistance, current or emerging chemotherapies have a relatively low success rates. This emphasizes the importance of discovering new compounds that are both safe and effective against melanoma. In vitro testing of melanoma cell lines and murine melanoma models offers the opportunity for identifying mechanisms of action of plant derived compounds and extracts. Common anti-melanoma effects of natural compounds include potentiating apoptosis, inhibiting cell proliferation and inhibiting metastasis. There are different mechanisms and pathways responsible for anti-melanoma actions of medicinal compounds such as promotion of caspase activity, inhibition of angiogenesis and inhibition of the effects of tumor promoting proteins such as PI3-K, Bcl-2, STAT3 and MMPs. This review thus aims at providing an overview of anti-cancer compounds, derived from natural sources, that are currently used in cancer chemotherapies, or that have been reported to show anti-melanoma, or anti-skin cancer activities. Phytochemicals that are discussed in this review include flavonoids, carotenoids, terpenoids, vitamins, sulforaphane, some polyphenols and crude plant extracts.Molecules 08/2014; 19(8):11679-11721. DOI:10.3390/molecules190811679 · 2.10 Impact Factor
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ABSTRACT: Vitamin D supplementation appears to be potential for reducing risks of cancer, cardiovascular disease, and other chronic diseases, existing evidence on its benefits and risks is inadequate and debatable. Questions remain as to whether supplementation of Vitamin D playing any role in the above mentioned diseases. In the absence of compelling evidence for benefit, taking supplement is producing any risk or not. While sorting the various positive and negative claims for Vitamin D, it attracts an urgent need for further research and review on reports to answer fundamental questions about the risks and benefits of supplementation. There still remains a great need to advance our understanding regarding the effectiveness of Vitamin D. This review gives an overview on disputes of Vitamin D supplementation that is convincing and interventional regarding burning issues of Vitamin D therapy. Beyond its use to prevent osteomalacia or rickets, the evidence for other health effects of vitamin D supplementation in the general inhabitants is conflicting. It is a well known predictability that any effective substance also has unwanted side effects, so clear cut evidence regarding the safety is required before supplementing Vitamin D for pathological conditions and other health benefits.International Food Research Journal 01/2014; 21(6):2075-2081.