Vitamin D slows progression of cancer malignancy

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A team of researchers at McGill University have discovered a molecular basis for the potential cancer preventive effects of vitamin D. The team, led by McGill professors John White and David Goltzman, of the Faculty of Medicine’s Department of Physiology, discovered that the active form of vitamin D acts by several mechanisms to inhibit both the production and function of the protein cMYC. cMYC drives cell division and is active at elevated levels in more than half of all cancers. Their results are published in the latest edition of Proceedings of the National Academy of Sciences.  sunshine-vitamin-d

Although vitamin D can be obtained from limited dietary sources and directly from  exposure to the sun during the spring and summer months, the combination of poor    dietary intake and sun avoidance has created vitamin D deficiency or insufficiency in large proportions of many populations worldwide. It is known that vitamin D has a wide range of physiological effects and that correlations exist between insufficient amounts of vitamin D and an increased incidence of a number of cancers. These correlations are particularly  strong for cancers of the digestive tract, including colon cancer, and certain forms of leukemia.

“For years, my lab has been dedicated to studying the molecular mechanisms of vitamin D in human cancer cells, particularly its role in stopping their proliferation,” said Prof. White. “We discovered that vitamin D controls both the rate of production and the degradation of cMYC. More importantly, we found that vitamin D strongly stimulates the production of a natural antagonist of cMYC called MXD1, essentially shutting down cMYC function.”

The team also applied vitamin D to the skin of mice and observed a drop in the level of cMYC and found evidence of a decrease in its function. Moreover, other mice, which lacked the specific receptor for vitamin D, were found to have strongly elevated levels of cMYC in a number of tissues including skin and the lining of the colon.

“Taken together, our results show that vitamin D puts the brakes on cMYC function, suggesting that it may slow the progression of cells from premalignant to malignant states and keep their proliferation in check. We hope that our research will encourage people to maintain adequate vitamin D supplementation and will stimulate the development of large, well-controlled cancer chemoprevention trials to test the effects of adequate supplementation,” said Dr. White.

This work was funded by the Canadian Institutes of Health Research and the National Cancer Institute/Canadian Cancer Society Research Institute.

Fonte: http://machineslikeus.com/news/vitamin-d-slows-progression-cancer-malignancy

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Anúncios

The effect of vitamin D and frailty on mortality among non-institutionalized US older adults

Assista aos vídeos:

Vitamina D – Sem Censura – Dr. Cicero Galli Coimbra e Daniel Cunha

Vitamina D – por uma outra terapia

Vitamin D – For an alternative therapy
 
The Real Story on Vitamin D

https://www.youtube.com/watch?v=Ad32GM5paok&list=UU5grjCGNi25VAR8J0eVuxVQ&index=1&feature=plcp

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European Journal of Clinical Nutrition advance online publication 13 June 2012; doi: 10.1038/ejcn.2012.67

E Smit1, C J Crespo2, Y Michael3, F A Ramirez-Marrero4, G R Brodowicz2, S Bartlett5 and R E Andersen5

  1. 1Department of Public Health, Oregon State University, Corvallis, OR, USA
  2. 2School of Community Health, Portland State University, Portland, OR, USA
  3. 3Department of Epidemiology and Biostatistics, Drexel University, Philadelphia, PA, USA
  4. 4Department of Exercise Science, University of Puerto Rico, San Juan, Puerto Rico
  5. 5Departments of Kinesiology and Physical Education, and Medicine, McGill University, Montréal, QC, Canada

Correspondence: Dr E Smit, Department of Public Health, Oregon State University, Waldo 316, Corvallis, OR 97331, USA. E-mail: Ellen.Smit@oregonstate.edu

Received 21 February 2012; Revised 30 April 2012; Accepted 30 April 2012
Advance online publication 13 June 2012


Abstract

BACKGROUND/OBJECTIVES:

Although both frailty and low vitamin D have been separately associated with an increased risk for adverse health, their joined effects on mortality have not been reported. The current study examined prospectively the effects of frailty and vitamin D status on mortality in US older adults.

SUBJECTS/METHODS:

Participants aged greater than or equal to60 years in The Third National Health and Nutrition Examination Survey with 12 years of mortality follow-up were included in the analysis (n=4731). Frailty was defined as meeting three or more criteria and pre-frailty as meeting one or two of the five frailty criteria (low body mass index (BMI), slow walking, weakness, exhaustion and low physical activity). Vitamin D status was assessed by serum 25-hydroxyvitamin D (25(OH)D) and categorized into quartiles. Analyses were adjusted for gender, race, age, smoking, education, latitude and other comorbid conditions.

RESULTS:

Serum 25(OH)D concentrations were lowest in participants with frailty, intermediate in participants with pre-frailty and highest in participants without frailty. The odds of frailty in the lowest quartile of serum 25(OH)D was 1.94 times the odds in the highest quartile (95%confidence interval (CI): 1.09–3.44). Mortality was positively associated with frailty, with the risk among participants who were frail and had low serum 25(OH)D being significantly higher than those who were not frail and who had high concentrations of serum 25(OH)D (hazards ratio 2.98; 95%CI: 2.01–4.42).

CONCLUSION:

Our results suggest that low serum 25(OH)D is associated with frailty, and there is additive joint effects of serum 25(OH)D and frailty on all-cause mortality in older adults.

Fonte: http://www.nature.com/ejcn/journal/vaop/ncurrent/abs/ejcn201267a.html

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