Group items tagged

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]

Vitamin D and type 2 diabetes: are we ready for a prevention trial? Scragg R. Diabetes. 2008 Oct;57(10):2565-6. PMID: 18820212 doi: 10.2337/db08-0879 Despite evidence from the current article (3) and the Finnish study (17), doubts still remain about whether low vitamin status is a cause of type 2 diabetes. Further cohort studies are required, assessing baseline vitamin D status using blood 25(OH)D to be sure that the Ely and Finnish studies are not false-positive results. Glucose clamp studies are also required because we are still not sure of the mechanism influenced by vitamin D-whether it is insulin resistance, secretion, or both. But most importantly, given that nearly three decades have passed since the first studies linking vitamin D with insulin metabolism (6,7), well-designed clinical trials of the effect of vitamin D supplementation on glycemia status and diabetes risk are urgently required to settle this question. And they need to prevent past mistakes. In particular, the vitamin D dose given in such trials needs to be high enough-above 2,000 IU per day (19)-to raise blood 25(OH)D levels above 80 nmol/l because diabetes risk is lowest at this level (9,20). If well-designed trials are carried out and confirm a protective effect from vitamin D, it could be used by the general population as a simple and cheap solution to help prevent the diabetes epidemic.

Vitamin D in preventive medicine: are we ignoring the evidence? Zittermann A. Br J Nutr. 2003 May;89(5):552-72. Review. PMID: 12720576 Vitamin D is metabolised by a hepatic 25-hydroxylase into 25-hydroxyvitamin D (25(OH)D) and by a renal 1alpha-hydroxylase into the vitamin D hormone calcitriol. Calcitriol receptors are present in more than thirty different tissues. Apart from the kidney, several tissues also possess the enzyme 1alpha-hydroxylase, which is able to use circulating 25(OH)D as a substrate. Serum levels of 25(OH)D are the best indicator to assess vitamin D deficiency, insufficiency, hypovitaminosis, adequacy, and toxicity. European children and young adults often have circulating 25(OH)D levels in the insufficiency range during wintertime. Elderly subjects have mean 25(OH)D levels in the insufficiency range throughout the year. In institutionalized subjects 25(OH)D levels are often in the deficiency range. There is now general agreement that a low vitamin D status is involved in the pathogenesis of osteoporosis. Moreover, vitamin D insufficiency can lead to a disturbed muscle function. Epidemiological data also indicate a low vitamin D status in tuberculosis, rheumatoid arthritis, multiple sclerosis, inflammatory bowel diseases, hypertension, and specific types of cancer. Some intervention trials have demonstrated that supplementation with vitamin D or its metabolites is able: (i) to reduce blood pressure in hypertensive patients; (ii) to improve blood glucose levels in diabetics; (iii) to improve symptoms of rheumatoid arthritis and multiple sclerosis. The oral dose necessary to achieve adequate serum 25(OH)D levels is probably much higher than the current recommendations of 5-15 microg/d.

Factors that influence the cutaneous synthesis and dietary sources of vitamin D. Chen TC, Chimeh F, Lu Z, Mathieu J, Person KS, Zhang A, Kohn N, Martinello S, Berkowitz R, Holick MF. Arch Biochem Biophys. 2007 Apr 15;460(2):213-7. Epub 2007 Jan 8. PMID: 17254541 doi: 10.1016/j.abb.2006.12.017 Vitamin D is rare in food. Among the vitamin D-rich food, oily fish are considered to be one of the best sources. Therefore, we analyzed the vitamin D content in several commonly consumed oily and non-oily fish. The data showed that farmed salmon had a mean content of vitamin D that was ~25% of the mean content found in wild caught salmon from Alaska, and that vitamin D2 was found in farmed salmon, but not in wild caught salmon. The results provide useful global guidelines for obtaining sufficient vitamin D3 by cutaneous synthesis and from dietary intake to prevent vitamin D deficiency and its health consequences.ensuing illness, especially, bone fractures in the elderly.

Tufts University Confirms That Vitamin A Protects Against Vitamin D Toxicity by Curbing Excess Production of Vitamin K-Dependent Proteins Tufts University confirmed my hypothesis that vitamin A protects against vitamin D's induction of renal calcification (kidney stones) by normalizing the production of vitamin K-dependent proteins in December, 2008, without citing my hypothesis or telling me they had confirmed it. I am, of course, very grateful that they thought it significant enough to investigate.

Vitamin D: a D-Lightful health perspective. Holick MF. Nutr Rev. 2008 Oct;66(10 Suppl 2):S182-94. Review. PMID: 18844847 DOI: 10.1111/j.1753-4887.2008.00104.x Sunlight provides most humans with their vitamin D requirement. Adequate vitamin D(3) by synthesis in the skin or from dietary and supplemental sources is essential for bone health throughout life. Vitamin D deficiency is defined as a 25(OH)D concentration 30 ng/mL (75 nmol/L), and insufficiency as 21-29 ng/mL. Vitamin D deficiency and insufficiency has been linked to a wide variety of chronic diseases including common cancers, autoimmune, cardiovascular, and infectious diseases. Healthcare professionals need to be aware of the vitamin D deficiency pandemic. Guidelines for sensible sun exposure and supplemental vitamin D of 800-1000 IU/day are needed.

Why is it that vitamin D deficiency can manifest in so many different ways in different people? One big reason is something called vitamin D receptor (VDR) genotypes, the variation in the receptor for vitamin D. Why is it that the dose of vitamin D necessary to reach a specific level differs so widely from one person to the next? VDR genotype, again. Variation in blood levels of 25-hydroxy vitamin D from a specific dose of vitamin D can vary three-fold, as shown by a University of Toronto study. In other words, a dose of 4000 units per day may yield a 25-hydroxy vitamin D blood level of 30 ng/ml in Mary, 60 ng/ml in Paul, and 90 ng/ml in Pete--same dose, different blood levels

"The major factor which stimulates weight gain in winter months is vitamin D. Human bodies get vitamin D from sunlight; as the hours of sunlight become less with the onset of fall, so our levels of vitamin D decrease. Low levels of vitamin D affect the brain's production of the hormone leptin. Leptin plays a vital role in controlling appetite and metabolism; so as the amount of vitamin D in our bodies decreases so does the leptin, and this causes an increase in our appetite and a change in our metabolism. Researchers at Aberdeen University found that obese people had 10% less vitamin D than people of average weight. The study also found that excess body fat absorbed vitamin D so the body couldn't use it. Scientists now believe that there is a direct correlation between obesity and low levels of vitamin D.

Serum vitamin D concentration and prostate cancer risk: a nested case-control study. Ahn J, Peters U, Albanes D, Purdue MP, Abnet CC, Chatterjee N, Horst RL, Hollis BW, Huang WY, Shikany JM, Hayes RB; Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial Project Team. J Natl Cancer Inst. 2008 Jun 4;100(11):796-804. Epub 2008 May 27. PMID: 18505967 doi:10.1093/jnci/djn152 CONCLUSION: The findings of this large prospective study do not support the hypothesis that vitamin D is associated with decreased risk of prostate cancer; indeed, higher circulating 25(OH)D concentrations may be associated with increased risk of aggressive disease. In summary, results from this large prospective study of men who underwent standardized prostate cancer screening in the context of a screening trial do not support the hypothesis that higher serum vitamin D status is associated with decreased risk of prostate cancer. The study showed no association of vitamin D level with nonaggressive disease; however, it raises the possibility that higher vitamin D level may be associated with increased risks for aggressive disease, although a clear monotonic dose-response relationship was lacking. Along with recent reports of adverse associations for higher vitamin D status and risk of pancreatic (32) and esophageal (33,34) cancer, caution should be taken in recommending high doses of vitamin D or sunlight exposure to the general public for prostate cancer prevention. Future analyses are warranted to confirm these results and to further clarify the effects of vitamin D on aggressive prostate cancer.

"Hi! This is Amy Proal. I wrote the article referenced at the start of the thread about vitamin D. Dr. Marshall is not concerned with vitamin D toxicity. Rather his molecular modeling research has clarified the actions of the two vitamin D metabolites 25-D and 1,25-D. The Vitamin D Receptor (VDR) is a fundamental receptor of the body - it controls the expression thousands of genes, as well as the activity of the innate immune system and the antimicrobial peptides. If you think of the VDR as a switch, 25-D (which is a corticosteroid) turns it off (inactivates it) and 1,25-D turn it on (activates it). What is commonly believed among vitamin D researchers is that if people supplement with extra vitamin D it will be converted into 1,25-D and activate the VDR. Unfortunately, Marshall's work revealed that the type of vitamin D derived from supplements and sun remains, for the most part, in it's precursor form 25-D. This means that the extra vitamin D we get from fortified food products and supplements is turning the VDR off, not on. That causes a decrease in immune function and gene transcription."

(VIDEO) Shedding light on the vitamin D deficiency 'crisis' By GrassRootsHealth.com Oct 11, 2009 - 4:49:39 PM San Diego, CA - Can vitamin D prevent 80% of the incidence of breast cancer? What is its affect on colon cancer and other major illnesses? These questions and more will be addressed when some of the most prominent vitamin D researchers in North America participate in the " Diagnosis & Treatment of Vitamin D Deficiency" seminar presented by GrassrootsHealth at the University of Toronto on Tuesday, November 3 from 8 a.m. - 5 p.m. GrassrootsHealth is the founder of D*action, an international public health project whose goal is to solve the vitamin D deficiency epidemic. GrassrootsHealth and D*action work with over 30 scientists, institutions and individuals committed to educate, test, and study vitamin D levels worldwide. At the conference, a group of physicians and researchers in the vitamin D field will discuss vitamin D's role in the potential prevention of many diseases, including breast cancer, colon cancer, type 1 diabetes and multiple sclerosis, the ultimate reduction in the incidence of infectious diseases and the economic impact of such action

Defining Adequate Vitamin D Intake : Cross-sectional and Intervention Studies Viljakainen, Heli Tuulikki University of Helsinki 2008-05-23 Doctoral dissertation (article-based) Vitamin D is required for normal bone growth and maintenance of the skeleton throughout life. In Finland, like in many other Western countries, the population suffers from inadequate or deficient vitamin D status, especially during winter, which is thought to increase the risk of osteoporosis. New strategies to prevent osteoporosis are actively being sought. The main objective of this thesis was to determine whether vitamin D is feasible in the primary prevention of osteoporosis; does it affect bone mineral accrual during the growth period? A second goal was to ascertain whether seasonal variation in calcitropic hormones affects bone remodelling, and to elucidate the vitamin D intake needed to overcome this variation in different age groups. In summary, vitamin D intake remains inadequate among the target groups of this thesis, as reflected by seasonal variation in calcitropic hormones and bone metabolism. Dietary intake of vitamin D should be increased to achieve at least an adequate vitamin D status (S-25-OHD>50 nmol/l) and possibly an optimal vitamin D status (S-25-OHD>80 nmol/l) throughout the year. This could be accomplished by introducing new vitamin D-fortified foods to the market."

"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."

"June 29, 2009 | Shelley Wood Boston, MA - A massive, National Institutes of Health-sponsored study looking at whether vitamin-D and/or omega-3 fatty-acid supplementation can reduce the risk of developing heart disease, stroke, or cancer will get under way in January 2010, according to a website for the study. Drs JoAnn Manson and Julie Buring (Harvard Medical School/ Brigham and Women's Hospital, Boston, MA) will head up the Vitamin D and Omega-3 Trial (VITAL). The study is aiming to enroll 20 000 men and women, one-quarter of whom will be black. According to a Brigham and Women's Hospital press release, the study is intentionally aiming to illuminate a potential racial and ethnic disparity hypothesized to be linked to vitamin D [1]. "African Americans have a higher risk of vitamin-D deficiency as well as a greater frequency of diabetes, hypertension, and certain types of cancer," a press release notes. For VITAL, women need to be over age 65 to enter the study; men need to be over age 60. Study participants will be randomized to one of four groups: daily vitamin D (2000 IU) and fish oil (1 g); daily vitamin D and fish-oil placebo; daily vitamin-D placebo and fish oil; or daily vitamin-D placebo and fish-oil placebo. The trial will run for five years and is expected to cost US $20 million."

Vitamin D and diabetes: improvement of glycemic control with vitamin D3 repletion. Schwalfenberg G. Can Fam Physician. 2008 Jun;54(6):864-6. PMID: 18556494 Conclusion These cases support information that is already known about VTD and its effect on the islet cell. As discussed above, this might be true only for vitamin D3 and not vitamin D2, although vitamin D2 has been shown to improve bone health. Vitamin D insufficiency or deficiency is common, and repletion might improve glycemic control early in type 2 diabetes. Diabetes is one of the fastest growing chronic diseases worldwide. Vitamin D3 is inexpensive and readily available. Well-designed clinical studies are required to ascertain if improving 25(OH)D levels from an insufficiency or deficiency to sufficiency improves glycemic control in diabetes. These studies need to be properly designed: a randomized controlled trial with VTD deficiency or insufficiency identified in diabetic patients of various ethnic

A critical review of Vitamin D and cancer: A report of the IARC Working Group on vitamin D William B. Grant Dermato-Endocrinology. Volume 1, Issue 1 January/February 2009 Pages: 25 - 33 The International Agency for Research on Cancer (IARC) released a report, Vitamin D and Cancer, on November 25, 2008. The report focused on the current state of knowledge and level of evidence of a causal association between vitamin D status and cancer risk. Although presenting and evaluating evidence for the beneficial role of UVB and vitamin D in reducing the risk of cancer, it discounted or omitted important evidence in support of the efficacy of vitamin D. The report largely dismissed or ignored ecological studies on the grounds that confounding factors might have affected the findings. The report accepted a preventive role of vitamin D in colorectal cancer but not for breast cancer.

Daily duration of vitamin D synthesis in human skin with relation to latitude, total ozone, altitude, ground cover, aerosols and cloud thickness. Engelsen O, Brustad M, Aksnes L, Lund E. Photochem Photobiol. 2005 Nov-Dec;81(6):1287-90. PMID: 16354110 Vitamin D production in human skin occurs only when incident UV radiation exceeds a certain threshold. From simulations of UV irradiances worldwide and throughout the year, we have studied the dependency of the extent and duration of cutaneous vitamin D production in terms of latitude, time, total ozone, clouds, aerosols, surface reflectivity and altitude. For clear atmospheric conditions, no cutaneous vitamin D production occurs at 51 degrees latitude and higher during some periods of the year. At 70 degrees latitude, vitamin D synthesis can be absent for 5 months. Clouds, aerosols and thick ozone events reduce the duration of vitamin D synthesis considerably, and can suppress vitamin D synthesis completely even at the equator. A web page allowing the computation of the duration of cutaneous vitamin D production worldwide throughout the year, for various atmospheric and surface conditions, is available on the Internet at http://zardoz.nilu.no/~olaeng/fastrt/VitD.html and http://zardoz.nilu.no/~olaeng/fastrt/VitD-ez.html. The computational methodology is outlined here.

Vitamin D is associated with improved survival in early-stage non-small cell lung cancer patients. Zhou W, Suk R, Liu G, Park S, Neuberg DS, Wain JC, Lynch TJ, Giovannucci E, Christiani DC. Cancer Epidemiol Biomarkers Prev. 2005 Oct;14(10):2303-9. PMID: 16214909 In conclusion, the joint effects of surgery season and recent vitamin D intake seem to be associated with the survival of early-stage non-small cell lung cancer patients. In summary, for early-stage NSCLC patients, patients who had surgery in summer with "high" recent vitamin D intake have a statistically significantly improved RFS and OS than patients who had surgery in winter with "low" vitamin D intake. These results should be confirmed in a prospective study to assess the serum vitamin D levels at time of surgery. If the results are confirmed, our results, combined with findings in other studies, suggest that dietary vitamin D supplementation may be advisable for early stages of lung cancer patients, particularly during the winter season and in groups that tend to be deficient in vitamin D.

Commonly recommended daily intake of vitamin D is not sufficient if sunlight exposure is limited. Glerup H, Mikkelsen K, Poulsen L, Hass E, Overbeck S, Thomsen J, Charles P, Eriksen EF. J Intern Med. 2000 Feb;247(2):260-8. PMID: 10692090 Conclusions. Severe vitamin D deficiency is prevalent amongst sunlight-deprived individuals living in Denmark. In veiled Arab women, vitamin D deficiency is the result of a combination of limitations in sunlight exposure and a low oral intake of vitamin D. The oral intake of vitamin D amongst veiled ethnic Danish Moslems was, however, very high, at 13.53 µg (approximately 600 IU), but they were still vitamin D-deficient. Our results suggest that the daily oral intake of vitamin D in sunlight-deprived individuals should exceed 600 IU; most probably it should be 1000 IU day-1 to secure a normal level of 25-hydroxyvitamin D. This finding is in contrast with the commonly used RDA (recommended daily allowance) for adults in Europe: 200 IU day-1.

The role of vitamin D in cancer prevention. Garland CF, Garland FC, Gorham ED, Lipkin M, Newmark H, Mohr SB, Holick MF. Am J Public Health. 2006 Feb;96(2):252-61. Epub 2005 Dec 27. Review. PMID: 16380576 DOI: 10.2105/AJPH.2004.045260 Vitamin D status differs by latitude and race, with residents of the northeastern United States and individuals with more skin pigmentation being at increased risk of deficiency. A PubMed database search yielded 63 observational studies of vitamin D status in relation to cancer risk, including 30 of colon, 13 of breast, 26 of prostate, and 7 of ovarian cancer, and several that assessed the association of vitamin D receptor genotype with cancer risk. The majority of studies found a protective relationship between sufficient vitamin D status and lower risk of cancer. The evidence suggests that efforts to improve vitamin D status, for example by vitamin D supplementation, could reduce cancer incidence and mortality at low cost, with few or no adverse effects