Diapositiva 1

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Vitamin D deficiency A global perspective.Bandei
ra 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 7-dehydrocholesterol
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.
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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.
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J Nutr. 2007 Nov137(11 Suppl)2576S-2579S.
Related Articles, Links /entrez/utils/fref.fcgi?P
rId3051itoolAbstract-defuid17951506dbpubmed
urlhttp//jn.nutrition.org/cgi/pmidlookup?viewl
ongpmid17951506/entrez/utils/fref.fcgi?PrId3051
itoolAbstract-defuid17951506dbpubmedurlhtt
p//jn.nutrition.org/cgi/pmidlookup?viewlongpmid
17951506Dietary modulation of colon cancer
risk.Kim YS, Milner JA.Nutritional Science
Research Group, Division of Cancer Prevention,
National Cancer Institute, Bethesda, MD 20892,
USA. yk47s_at_nih.govColon 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.
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Dermatol Clin. 2007 Oct25(4)515-23, viii.
Related Articles, Links /entrez/utils/fref.fcgi?P
rId3048itoolAbstract-defuid17903610dbpubmed
urlhttp//linkinghub.elsevier.com/retrieve/pii/S
0733-8635(07)00062-9/entrez/utils/fref.fcgi?PrId3
048itoolAbstract-defuid17903610dbpubmedurl
http//linkinghub.elsevier.com/retrieve/pii/S0733-
8635(07)00062-9The vitamin D receptor.Carlberg
C, Seuter S.Life Sciences Research Unit,
Universitè of Luxembourg, 162A, Avenue de la
Faïencerie, L-1511 Luxembourg, Luxembourg.
carsten.carlberg_at_uni.luThe 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.
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Acta Med Indones. 2007 Jul-Sep39(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.