Transcript Diapositiva 1

Vitamin D deficiency: A global perspective.
Bandeira F, Griz L, Dreyer P, Eufrazino C, Bandeira C, Freese E.
Vitamin D is essential for the maintenance of good health. Its sources can be
skin production and diet intake. Most humans depend on sunlight exposure
(UVB 290-315 nm) to satisfy their requirements for vitamin D. Solar ultraviolet
B photons are absorbed by the skin, leading to transformation of 7dehydrocholesterol into vitamin D3 (cholecalciferol). Season, latitude, time of
day, skin pigmentation, aging, sunscreen use, all influence the cutaneous
production of vitamin D3. Vitamin D deficiency not only causes rickets among
children but also precipitates and exacerbates osteoporosis among adults and
causes the painful bone disease osteomalacia. Vitamin D deficiency has
been associated with increased risk for other morbidities such as
cardiovascular disease, type 1 and type 2 diabetes mellitus and
cancer, especially of the colon and prostate. The prevalence of
hypovitaminosis D is considerable even in low latitudes and should be taken
into account in the evaluation of postmenopausal and male osteoporosis.
Although severe vitamin D deficiency leading to rickets or osteomalacia is rare
in Brazil, there is accumulating evidence of the frequent occurrence of
subclinical vitamin D deficiency, especially in elderly people.
Curr Med Res Opin. 2007 Nov 21 Molecular basis of the potential of vitamin D to prevent cancer.
Ingraham BA, Bragdon B, Nohe A.
OBJECTIVE: To review current research findings in cell biology, epidemiology, preclinical, and clinical trials
on the protective effects of vitamin D against the development of cancers of the breast, colon, prostate, lung,
and ovary. Current recommendations for optimal vitamin D status, the movement towards revision of
standards, and reflections on healthy exposure to sunlight are also reviewed.Search methodology: A literature
search was conducted in April and updated in September 2007. The Medline and Web of Knowledge databases
were searched for primary and review articles published between 1970 and 2007, using the search terms
vitamin D, calcitriol, cancer, chemoprevention, nuclear receptor, vitamin D receptor, apoptosis, cell cycle,
epidemiology, and cell adhesion molecule. Articles that focused on epidemiological, preclinical, and clinical
evidence for vitamin Ds effects were selected and additional articles were obtained from reference lists of the
retrieved articles.FINDINGS: An increasing body of research supports the hypothesis that the active form of
vitamin D has significant, protective effects against the development of cancer. Epidemiological studies show
an inverse association between sun exposure, serum levels of 25(OH)D, and intakes of vitamin D and risk of
developing and/or surviving cancer. The protective effects of vitamin D result from its role as a nuclear
transcription factor that regulates cell growth, differentiation, apoptosis and a wide range of cellular
mechanisms central to the development of cancer. A significant number of individuals have serum vitamin D
levels lower than what appears to protect against cancer, and the research community is currently revising the
guidelines for optimal health. This will lead to improved public health policies and to reduced risk of
cancer.CONCLUSIONS: Research strongly supports the view that efforts to improve vitamin D status
would have significant protective effects against the development of cancer. The clinical research
community is currently revising recommendations for optimal serum levels and for sensible levels of sun
exposure, to levels greater than previously thought. Currently, most experts in the field believe that intakes of
between 1000 and 4000 IU will lead to a more healthy level of serum 25(OH)D, in the range of 75 nmol/L that
will offer significant protect effects against cancers of the breast, colon, prostate, ovary, lungs, and pancreas.
The first randomized trial has shown significant protection against breast cancer, and other clinical trials will
follow and ultimately lead to improved public health policies and significantly fewer cancers.
J Nutr. 2007 Nov;137(11 Suppl):2576S-2579S.
Related Articles, Links /entrez/utils/fref.fcgi?PrId=3051&itool=Abstractdef&uid=17951506&db=pubmed&url=http://jn.nutrition.org/cgi/pmidlookup?view=long&pmid=17951506/entrez/utils/fref.fcgi?PrId=305
1&itool=Abstract-def&uid=17951506&db=pubmed&url=http://jn.nutrition.org/cgi/pmidlookup?view=long&pmid=17951506
Dietary modulation of colon cancer risk.
Kim YS, Milner JA.
Nutritional Science Research Group, Division of Cancer Prevention, National Cancer Institute, Bethesda, MD 20892,
USA. [email protected]
Colon cancer remains a significant global health concern. The impact of specific dietary components on colon tissue
likely depends on a host of genomic processes that influence the growth, development, and differentiation of the
epithelial cells at the colon crypt surface, where the balance between proliferation and differentiation is maintained
possibly through the Wnt (beta-catenin/T-cell factor) signaling pathway. A loss of balance caused by either genetic
mutations or environmental factors such as dietary habits can modulate the risk for the formation of aberrant crypt foci
and ultimately the development of colon cancer. Evidence exists that butyrate reduces the number and the size of
aberrant crypt foci in the colon. Butyrate is a natural histone deacetylase inhibitor as well as a molecule involved with
enhanced TGF-beta-induced SMAD3 phosphorylation, increased IFN-gamma-mediated apoptosis, and altered
expression of the intestinal muc2 gene that is responsible for mucin synthesis. Other dietary components, such as
vitamin D and (n-3) fatty acids, may regulate proliferative properties of colon progenitor cells as well as the
differentiation of subcellular lineages. Although these findings are intriguing, there are uncertainties that remain to be
resolved including the optimal exposure needed to bring about an effect, the appropriate timing of administration, and
if nutrient-nutrient and nutrient-gene interactions determine the overall response. The expanded use of high-throughput
technologies, knowledge about the expression of genes and protein fingerprints, and metabolomic profiling will assist
in addressing these issues and ultimately in determining the physiological significance of bioactive food components as
cancer protectants.
Dermatol Clin. 2007 Oct;25(4):515-23, viii.
Related Articles, Links /entrez/utils/fref.fcgi?PrId=3048&itool=Abstractdef&uid=17903610&db=pubmed&url=http://linkinghub.elsevier.com/retrieve/pii/S0733-8635(07)000629/entrez/utils/fref.fcgi?PrId=3048&itool=Abstractdef&uid=17903610&db=pubmed&url=http://linkinghub.elsevier.com/retrieve/pii/S0733-8635(07)00062-9
The vitamin D receptor.
Carlberg C, Seuter S.
Life Sciences Research Unit, Universitè of Luxembourg, 162A, Avenue de la Faïencerie, L-1511 Luxembourg, Luxembourg.
[email protected]
The vitamin D endocrine system is known for its essential role in calcium homeostasis and bone metabolism, and induces cell
differentiation, inhibits cell growth, controls other hormonal systems, and modulates the immune response. Vitamin D(3) is a prohormone
that is taken up by diet or synthesized in ultraviolet radiation-exposed skin and metabolically converted to the active metabolite,
1alpha,25-dihydroxyvitamin D(3). This nuclear hormone binds with high affinity the nuclear receptor vitamin D receptor. More than 3000
synthetic analogs of 1alpha,25(OH)(2)D(3) are known. This review aims to provide an overview on vitamin D signaling from the skin
perspective.
Acta Med Indones. 2007 Jul-Sep;39(3):133-41. Related Articles, Links
Vitamin D and autoimmune disease.
Ginanjar E, Sumariyono , Setiati S, Setiyohadi B.
Department of Internal Medicine, Faculty of Medicine, University of Indonesia, dr. Cipto
Mangunkusumo Hospital, Jakarta.
Vitamin D as a part of the endocrine system is an important component in the interaction
between the kidney, bone, parathyroid hormone, and the intestine, which maintains
extracellular calcium level within normal limits, in order to keep the vital physiologic process
and skeletal integrity. Vitamin D is also associated with hypertension, muscular function,
immunity, and ability to encounter infection, autoimmune disease, and cancer. The role of
vitamin D in immunity is a feedback reaction of paracrine to eliminate inflammation or to
influence CD4 T-cell differentiation and or to increase the function of T suppressor cell or
combination between both. The active form of vitamin D produces and maintains self
immunologic tolerance, some studies show that 1,25(OH)2D inhibits induction of disease in
autoimmune encephalomyelitis, thyroiditis, type-1 diabetes mellitus, inflammatory bowel
disease (IBD), systemic lupus erythematosus, and collagen-induced arthritis and Lyme
arthritis.