William B Grant

..In the absence of adequate solar UVB irradiation due to season, latitude, or lifestyle, vitamin D can be obtained from fortified food, oily fish, vitamin D supplements, and artificial sources of UVB radiation...

..Further research is required to confirm these estimates...

..It is noted that mechanisms whereby vitamin D exerts its effect are generally well understood for the various conditions and diseases discussed here...

..Based on these results, it seems worthwhile to conduct observational, prevention and intervention studies to further test the hypothesis that vitamin D can reduce the risk of cancer incidence and death...

..Solar ultraviolet-B (UVB) and vitamin D have been found inversely correlated with cancer incidence, mortality, and survival rates in many studies...

..However, the previous ecologic study of UVB and cancer mortality rates in the U.S. (Grant, 2002) did not include other risk factors in the analysis...

..This assumption has been questioned...

..These findings are probably still approximately correct, if not on the low side, with respect to vitamin D because of the additional benefits found recently, such as protection against infectious diseases...

..Additional randomized controlled trials are warranted to evaluate the benefits and risks of vitamin D supplementation. However, steps to increase serum 25(OH)D levels can be implemented now based on what is already known...

..They also provide more evidence that melanoma and NMSC have different etiologies...

..Doing so would pose only minimal increased risks of melanoma or skin cancer or hypercalcemia...

..Providing 1,000 IU of vitamin D per day for all adult Americans would cost about $1 billion; the expected benefits for cancer would be in the range of $16-25 billion in addition to other health benefits of vitamin D...

..In Nordic countries, less skin is generally exposed (in head and neck regions, the most frequent sites of squamous cell carcinoma) resulting in reduced vitamin D production...

..Development of elastosis seems to explain why long-term smoking and chronic UV irradiance reduce the risk of melanoma. Further work is required to elucidate the mechanism whereby elastosis retards and reduces the development of melanoma...

..The purpose of this review is to summarize ecological studies of solar ultraviolet B (UVB), vitamin D and cancer since 2000...

..In general, the evidence supports the hypothesis. However, further work is required to evaluate this hypothesis...

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..This report estimates the reduction in mortality rates for the five Nordic countries for an increase in population mean serum 25-hydroxyvitamin D level to 105 nmol/L...

..Liver cancer and NPC are linked to viruses, and UVR may increase the risk through immunosuppression. Further studies are warranted...

..9% (3.8-10.0%) or $14.4 billion ($8.0 billion-$20.1 billion) less the cost of the program. It is recommended that Canadian health policy leaders consider measures to increase serum 25(OH)D levels for all Canadians...

..While additional randomized controlled trials would, of course, be helpful, the current evidence seems to satisfy the criteria for causality as outlined by A. Bradford Hill...

..Further study is required to elucidate the mechanisms and develop guidelines for optimal vitamin D sources and serum levels of vitamin D metabolites...

..This paper reviews ecological studies of the ultraviolet-B (UVB)-vitamin D-cancer hypothesis based on geographical variation of cancer incidence and/or mortality rates...

..Future prospective studies should include more serum 25(OH)D level measurements during the study course...

..Dietary iron and zinc affect the risk of cancer, with dietary iron generally correlated with increased risk and dietary zinc with reduced risk. However, zinc supplements have been found correlated with increased risk of cancer...

..Although this evidence is supportive, there do not appear to be observational studies of incidence of dementia with respect to prediagnostic serum 25(OH)D or vitamin D supplementation. Such studies now appear to be warranted...

..If this result is correct, melanoma risk is not related to ozone depletion. We consider the net effect of solar UVB on human health to be beneficial at or near current levels...

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..Risk of nonmelanoma skin cancer is higher, but such cancers are seldom fatal, and a study in Denmark found a 9% reduction in 10-year all-cause mortality rate for patients diagnosed with basal cell carcinoma...

..Air pollution also plays a role in cancer risk...

..The ApoE4-diet-GDP hypothesis may explain the higher risk of prostate cancer for African Americans and should form the basis for further studies...

..81 (p < 0.0001). There was a protective effect of UVB irradiance on risk of breast cancer that was independent of fertility rate, proportion of the population overweight, alcohol intake, animal energy intake, and other covariates...

..Within eight weeks after the last exposure the 25(OH)D(3) level decreased to the initial value in all volunteers irrespective of vitamin D supplementation or not...

..Another objective was to explore whether the annual prostate cancer rates correlated more strongly with the cumulative UVB exposure for the year or for exposure during certain seasons...

..Case-control and cohort studies generally find a variety of chemical, nonfat dietary, environmental, genetic, lifestyle, and reproductive factors to be important...

..The objective of this research is to identify and determine the relative importance of dietary and environmental risk and risk reduction factors for prostate cancer mortality...

..These studies add further support for the role of UV-B radiation and vitamin D in reducing the risk of a large number of cancers...

..This suggests that lower levels of solar irradiance might be associated with higher risk of ovarian cancer. Laboratory findings also suggest that low levels of vitamin D metabolites could play a role in the etiology of ovarian cancer...

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..Previous studies, such as the Women's Health Initiative, have shown that a low dose of vitamin D did not protect against colorectal cancer, yet a meta-analysis indicates that a higher dose may reduce its incidence...

..The purpose of the current study was to determine how many types of cancer are affected by solar radiation and how many premature deaths from cancer occur due to insufficient ultraviolet (UV)-B radiation...

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..0001) were positively associated (R(2) = 0.68, p < 0.0001). Lower levels of UVB irradiance and higher intakes of calories from animal sources were independently associated with higher incidence rates of kidney cancer...

..Prompt public health action is needed to increase intake of Vitamin D(3) to 1000IU/day, and to raise 25-hydroxyvitamin D by encouraging a modest duration of sunlight exposure...