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A multicountry ecologic study of risk and risk reduction factors for prostate cancer mortality. Grant WB. Eur Urol. 2004 Mar;45(3):271-9. PMID: 15036670 CONCLUSIONS: These results are consistent with insulin-like growth factor-I (IGF-I), being an important risk factor for prostate cancer, with alcohol and calcium being less important risk factors, and with allium family vegetables, and, to a lesser extent, vitamin D being important risk reduction factors. These results should provide guidance for additional studies on dietary and environmental links to prostate cancer.

"For more than 80 years, scientists have known that vitamin D is important for building bones. And for most of those 80 years, people thought this was the only thing it was good for. In the past decade, however, we've learned two important things about vitamin D: it appears to have many other important health effects, and many Americans don't get enough of it. In 2008, new research pointed to a vitamin D deficiency as a possible contributing factor in heart disease. And the suspected link between vitamin D deficiency and cancer grew even stronger. This surely will spur much new research in 2009. Why is vitamin D deficiency so common? The vitamin is made in our skin when sunlight strikes it. Many Americans-especially those who live in the northern part of the country, are elderly or have dark skin-don't soak up enough sun. And the vitamin isn't found in many foods. The main sources are fatty fish (such as salmon, mackerel, herring and sardines) and milk, cereal and juices that have been fortified with it. Vitamin D deficiency often is unsuspected because it causes no direct symptoms; like high blood pressure, it does its damage silently."

The clinical importance of vitamin D (cholecalciferol): a paradigm shift with implications for all healthcare providers. Vasquez A, Manso G, Cannell J. Altern Ther Health Med. 2004 Sep-Oct;10(5):28-36; quiz 37, 94. Review. PMID: 15478784

Nutrients, endpoints, and the problem of proof. Heaney RP. 2008 W. O. Atwater Memorial Lecture J Nutr. 2008 Sep;138(9):1591-5. PMID: 18716155 To sum up, I think that there would be general agreement to the effect that nutrition is important, despite the fact that the still growing number of failed trials of individual nutrients might suggest that no nutrient actually made much of a difference, a conclusion that is absurd on its face and ought to have alerted us to the possibility that there was something wrong with how we were investigating the matter. To provide the proof needed to sustain revised intake recommendations, we shall have to find a design better suited to nutrients than the randomized controlled trial as currently implemented, and we need to develop a series of global indices, nutrient by nutrient, which better capture the polyvalent nature of most nutrients. Perhaps it would be useful for the ASN, in collaboration with concerned governmental entities such as the USDA, to convene a workshop to address these structural issues. Such deliberation may well be arduous and frustrating, but it is terribly important and, in my view, well worth the effort.

Geographic variation of prostate cancer mortality rates in the United States: Implications for prostate cancer risk related to vitamin D. Grant WB. Int J Cancer. 2004 Sep 1;111(3):470-1; author reply 472. No abstract available. PMID: 15221981 10.1002/ijc.20220 The implications of our results and those of Tuohimaa et al.[1] include the following. Vitamin D supplementation should be undertaken in wintertime, a period when it is impossible to produce vitamin D by solar UVB exposure in northeastern states.[13] Given these new results, the optimal vitamin D intake and production and serum 25(OH)-vitamin D3 levels for prostate cancer appear to be lower than for other cancers. However, when developing guidelines for vitamin D fortification, many factors should be included in the analysis, including all of the potential health benefits and possible risks of vitamin D, as well as age, sex, residence, child-bearing status, etc.[14] Also, the suggestion that daily vitamin D3 supplement doses of 100 g (4,000 IU)/day are safe[15] should be reexamined. Finally, in terms of preventing prostate cancer, more attention should be given to diet, which has the greatest environmental impact on risk of prostate cancer, with animal products being important risk factors and vegetable products, especially onions and other allium family members, being important risk-reduction factors.[16]

They found some important trends. Granulocytes from people over 50 years old had a reduced ability to kill cancer cells, as did granulocytes from people with cancer. This raises the possibility that cancer is not simply the result of getting too old, but a very specific weakening of the immune system. The most important finding, however, was that the granulocytes' kung-fu grip declined dramatically during the winter months. Here's Dr. Cui: Nobody seems to have any cancer-killing ability during the winter months from November to April.

The high prevalence of vitamin D insufficiency across Australian populations is only partly explained by season and latitude. van der Mei IA, Ponsonby AL, Engelsen O, Pasco JA, McGrath JJ, Eyles DW, Blizzard L, Dwyer T, Lucas R, Jones G. Environ Health Perspect. 2007 Aug;115(8):1132-9. PMID: 17687438 doi: 10.1289/ehp.9937. Conclusion Vitamin D insufficiency is common over a wide latitude range in Australia. Season appears to be more important than latitude, but both accounted for less than one-fifth of the variation in serum 25(OH)D levels, highlighting the importance of behavioral factors. Current sun exposure guidelines do not seem to fully prevent vitamin D insufficiency, and consideration should be given to their modification or to pursuing other means to achieve vitamin D adequacy.

The vitamin D-antimicrobial peptide pathway and its role in protection against infection. Gombart AF. Future Microbiol. 2009 Nov;4:1151-65. PMID: 19895218 Vitamin D deficiency has been correlated with increased rates of infection. Since the early 19th century, both environmental (i.e., sunlight) and dietary sources (cod liver) of vitamin D have been identified as treatments for TB. The recent discovery that vitamin D induces antimicrobial peptide gene expression explains, in part, the 'antibiotic' effect of vitamin D and has greatly renewed interest in the ability of vitamin D to improve immune function. Subsequent work indicates that this regulation is biologically important for the response of the innate immune system to wounds and infection and that deficiency may lead to suboptimal responses toward bacterial and viral infections. The regulation of the cathelicidin antimicrobial peptide gene is a human/primate-specific adaptation and is not conserved in other mammals. The capacity of the vitamin D receptor to act as a high-affinity receptor for vitamin D and a low-affinity receptor for secondary bile acids and potentially other novel nutritional compounds suggests that the evolutionary selection to place the cathelicidin gene under control of the vitamin D receptor allows for its regulation under both endocrine and xenobiotic response systems. Future studies in both humans and humanized mouse models will elucidate the importance of this regulation and lead to the development of potential therapeutic applications

"(NaturalNews) People still don't get it: Vitamin D is the "miracle nutrient" that activates your immune system to defend you against invading microorganisms -- including seasonal flu and swine flu. Two months ago, an important study was published by researchers at Oregon State University. This study reveals something startling: Vitamin D is so crucial to the functioning of your immune system that the ability of vitamin D to boost immune function and destroy invading microorganisms has been conserved in the genome for over 60 million years of evolution. As this press release from Oregon State University (http://www.eurekalert.org/pub_relea...) explains: The fact that this vitamin-D mediated immune response has been retained through millions of years of evolutionary selection, and is still found in species ranging from squirrel monkeys to baboons and humans, suggests that it must be critical to their survival, researchers say. "The existence and importance of this part of our immune response makes it clear that humans and other primates need to maintain sufficient levels of vitamin D," said Adrian Gombart, an associate professor of biochemistry and a principal investigator with the Linus Pauling Institute at Oregon State University."

A longitudinal study of serum 25-hydroxyvitamin D and intact parathyroid hormone levels indicate the importance of vitamin D and calcium homeostasis regulation in multiple sclerosis. Soilu-Hänninen M, Laaksonen M, Laitinen I, Erälinna JP, Lilius EM, Mononen I. J Neurol Neurosurg Psychiatry. 2008 Feb;79(2):152-7. Epub 2007 Jun 19. PMID: 17578859 doi:10.1136/jnnp.2006.105320 Conclusions: The endocrine circuitry regulating serum calcium may be altered in MS. There is an inverse relationship between serum vitamin D level and MS clinical activity. The role of vitamin D in MS must be explored further.

Circulating vitamin D3 and 25-hydroxyvitamin D in humans: An important tool to define adequate nutritional vitamin D status. Hollis BW, Wagner CL, Drezner MK, Binkley NC. J Steroid Biochem Mol Biol. 2007 Mar;103(3-5):631-4. Epub 2007 Jan 10. PMID: 17218096 In the present study, we sought to investigate what circulating 25(OH)D levels would result in populations exhibiting no substrate limitations to the vitamin D-25-hydroxylase. To perform this, we chose two distinct populations. The first were individuals from a year-found sunny environment who spent a good deal of time outdoors. The second were a group of lactating women receiving a substantial daily oral dose of vitamin D3. Surprisingly, a study such as this previously had not been undertaken. There are several reasons for this. First, finding a group of sun-exposed individuals is not an easy task; in fact, we had to go to Hawaii to find them. Secondly, very few studies have been performed where subjects actually received adequate vitamin D3 supplementation to make them replete. Finally, it is very difficult and costly to measure circulating vitamin D3 and relate it to circulating 25(OH)D. The results of our study are far-reaching. This study also demonstrates that individuals can be vitamin D deficient with significant sun exposure if the skin area exposed is limited as was suggested several years ago (19). Finally, whether one receives their vitamin D3 orally or through UV exposure, the vitamin D-25-hydroxylase appears to handle it in an equivalent fashion with respect to maintaining circulating 25(OH)D levels. Thus, we believe that the relationship between circulating vitamin D and 25(OH)D may define adequate nutritional vitamin D status.

Vitamin D: importance in the prevention of cancers, type 1 diabetes, heart disease, and osteoporosis.\nHolick MF.\nAm J Clin Nutr. 2004 Mar;79(3):362-71. Review. Erratum in: Am J Clin Nutr. 2004 May;79(5):890.\nPMID: 14985208

Vitamin D deficiency an important, common, and easily treatable cardiovascular risk factor?\nLee JH, O'Keefe JH, Bell D, Hensrud DD, Holick MF.\nJ Am Coll Cardiol. 2008 Dec 9;52(24):1949-56. Review.\nPMID: 19055985

"Retinol-induced Intestinal Tumorigenesis in Min/+ Mice and Importance of Vitamin D Status. Hetland RB, Alexander J, Berg JP, Svendsen C, Paulsen JE. Anticancer Res. 2009 Nov;29(11):4353-60. PMID: 20032378 The effects of life-long dietary exposure, starting in utero, to high retinol, low vitamin D, or high retinol in combination with low vitamin D on intestinal tumorigenesis in Min/+ mice were investigated. In males, high retinol alone significantly increased the number (2.6-fold) and size (1.3-fold) of small intestinal tumours; in females no significant increase in tumour number or size was seen. In both genders, low vitamin D intake alone did not affect intestinal tumorigenesis. In males, intake of the combined high retinol/low vitamin D diet did not further increase the effects caused by high retinol alone. In females, however, the high retinol/low vitamin D-induced increase in tumour number (3.1-fold) and tumour size (1.5-fold) exceeded that of high retinol alone. In conclusion, a high dietary intake of retinol stimulated intestinal tumorigenesis in Min/+ mice. Furthermore, the results indicate a combined effect of high retinol and low vitamin D on tumorigenesis in females"

The importance of supplementation is the part of the healthy and active life. Hence, you need to understand for consuming it with your diet, so that you can eventually live a better and disease free life.

A German group has now shown that the important inflammatory marker, tumor necrosis factor (TNF), is also reduced by vitamin D supplementation. Many studies have implicated increased TNF levels in promoting cancer. In this study, a modest vitamin D dose of 3320 units (83 micrograms) was given vs. placebo. The 25-hydroxy D level reached in the treated group was 34.2 ng/ml (85.5 nmol/L), which resulted in a 26.5% reduction in TNF compared with 18.7% reduction (?) in the placebo group.

Holick, M. F., MacLaughlin, J. A. & Doppelt, S. H. (1981) Factors that influence the cutaneous photosynthesis of previtamin D3. Science 211:590-593 When human skin was exposed to simulated solar ultraviolet radiation, epidermal 7-dehydrocholesterol was converted to previtamin D3. During prolonged exposure to simulated solar ultraviolet radiation, the synthesis of previtamin D3 reached a plateau at about 10 to 15 percent of the original 7-dehydrocholesterol content, and previtamin D3 was photoisomerized to two biologically inert isomers, lumisterol3 and tachysterol3. Increases either in skin melanin concentration or in latitude necessitated increases in the exposure time to simulated solar ultraviolet radiation required to maximize the formation, but not the total content, of previtamin D3. In order of importance, the significant determinants limiting the cutaneous production of previtamin D3 are (i) photochemical regulation, (ii) pigmentation, and (iii) latitude.

Baseline serum 25-hydroxy vitamin d is predictive of future glycemic status and insulin resistance: the Medical Research Council Ely Prospective Study 1990-2000. Forouhi NG, Luan J, Cooper A, Boucher BJ, Wareham NJ. Diabetes. 2008 Oct;57(10):2619-25. Epub 2008 Jun 30. PMID: 18591391 doi: 10.2337/db08-0593 CONCLUSIONS: This prospective study reports inverse associations between baseline serum 25(OH)D and future glycemia and insulin resistance. These associations are potentially important in understanding the etiology of abnormal glucose metabolism and warrant investigation in larger, specifically designed prospective studies and randomized controlled trials of supplementation.

Plasma 25-hydroxyvitamin d is associated with markers of the insulin resistant phenotype in nondiabetic adults. Liu E, Meigs JB, Pittas AG, McKeown NM, Economos CD, Booth SL, Jacques PF. J Nutr. 2009 Feb;139(2):329-34. Epub 2008 Dec 23. PMID: 19106328 doi:10.3945/jn.108.093831 After adjusting for age and sex, plasma 25(OH)D was positively associated with ISI(0,120), plasma adiponectin, and HDL cholesterol and inversely associated with plasma triacylglycerol, but these associations were no longer significant after further adjustment for BMI, waist circumference, and current smoking status. 25(OH)D and 2-h post-OGTT glucose were not associated. Among adults without diabetes, vitamin D status was inversely associated with surrogate fasting measures of insulin resistance. These results suggest that vitamin D status may be an important determinant for type 2 diabetes mellitus.

Aging decreases the capacity of human skin to produce vitamin D3. MacLaughlin J, Holick MF. J Clin Invest. 1985 Oct;76(4):1536-8. PMID: 2997282 doi:10.1172/JCI112134 An evaluation of surgically obtained skin (age range, 8-92 yr) revealed that there is an age-dependent decrease in the epidermal concentrations of provitamin D3 (7-dehydrocholesterol). To ascertain that aging indeed decreased the capacity of human skin to produce vitamin D3, some of the skin samples were exposed to ultraviolet radiation and the content of previtamin D3 was determined in the epidermis and dermis. The epidermis in the young and older subjects was the major site for the formation of previtamin D3, accounting for greater than 80% of the total previtamin D3 that was produced in the skin. A comparison of the amount of previtamin D3 produced in the skin from the 8- and 18-yr-old subjects with the amount produced in the skin from the 77- and 82-yr-old subjects revealed that aging can decrease by greater than twofold the capacity of the skin to produce previtamin D3. Recognition of this difference may be extremely important for the elderly, who infrequently expose a small area of skin to sunlight and who depend on this exposure for their vitamin D nutritional needs.