Van alles m.b.t. Vitamine D

[vonneke]

Acta Neurol Scand Suppl. 2010;(190):88-92.

Assessing vitamin D in the central nervous system.

Holmøy T, Moen SM.

Department of Neurology, Oslo University Hospital Ullevål, Oslo, Norway. trygve.holmoy@rr-research.no

Abstract
Epidemiological and experimental evidence suggest that vitamin D deficiency is a risk factor for multiple sclerosis and other autoimmune diseases. The activated form of vitamin D exerts several immunomodulating properties in vitro and in vivo, that could contribute to explain the association with multiple sclerosis. Hypovitaminosis D is also associated with several other neurological diseases that is less likely mediated by dysregulated immune responses, including Parkinson's disease and Alzheimer's disease, schizophrenia and affective disorders, suggesting a more diverse role for vitamin D in the maintenance of brain health. Accordingly, both the vitamin D receptor and the enzymes necessary to synthesize bioactive 1,25-dihydroxyvitamin D are expressed in the brain, and hypovitaminosis D is associated with abnormal development and function of the brain. We here review current knowledge on the intrathecal vitamin D homeostasis in heath and disease, highlighting the need to assess vitamin D in the intrathecal compartment.

PMID: 20586743

[vonneke]

South Med J. 2010 Jul 8. [Epub ahead of print]

Effects of Vitamin D Supplementation on Blood Pressure.

Wu SH, Ho SC, Zhong L.

From the School of Public Health and Primary Care, The Chinese University of Hong Kong, Hong Kong SAR, People's Republic of China, and Nanjing Maternal and Child Health Care Hospital, Nanjing City, People's Republic of China; School of Public Health and Primary Care, The Chinese University of Hong Kong, Hong Kong SAR, People's Republic of China; and School of Basic Medical Science, Southeast University, People's Republic of China, and Department of Orthopaedics and Traumatology, Musculoskeletal Research Laboratory, The Chinese University of Hong Kong, Hong Kong SAR, People's Republic of China.

Abstract
OBJECTIVE:: Inconsistent findings from epidemiological studies have continued the controversy over the role of oral vitamin D supplementation in reducing blood pressure in normotensive or hypertensive populations.

METHODS:: We performed a literature search up to December 2009, with no restrictions. Only double-blind randomized controlled trials (RCTs) of oral vitamin D supplementation in normotensive or hypertensive individuals with blood pressure measurements were included.

RESULTS:: From 244 retrieved papers, four RCTs involving 429 participants met our inclusion criteria for this meta-analysis. Vitamin D supplementation reduced systolic blood pressure (SBP) by 2.44 mm Hg (weighted mean difference [WMD]: -2.44, 95% confidence interval [CI]: -4.86, -0.02), but not diastolic blood pressure (DBP) (WMD: -0.02, 95% CI: -4.04, 4.01) compared with calcium or placebo. Subgroup analysis suggested that the change of blood pressure did not vary markedly across the dose of vitamin D supplementation, study length, or intervention.

CONCLUSIONS:: Oral vitamin D supplementation may lead to a reduction in systolic blood pressure but not diastolic blood pressure. Given the small number of trials and small but statistically significant reduction in systolic blood pressure from this meta-analysis, further studies are required to confirm the magnitude of the effect of vitamin D on blood pressure reduction and define the optimum dose, dosing interval, and type of vitamin D to administer.

PMID: 20622727

[vonneke]

Vitamin D Expert Says More Than Half The World's Population Gets Insufficient Vitamin D:

http://www.medicalnewstoday.com/articles/195001.php

[vonneke]

J Clin Densitom. 2010 Jul 20. [Epub ahead of print]

Hypovitaminosis D and Bone Mineral Metabolism and Bone Density in Hyperthyroidism.

Dhanwal DK, Kochupillai N, Gupta N, Cooper C, Dennison EM.

MRC Epidemiology Resource Centre, Southampton General Hospital, University of Southampton, Southampton, UK; Maulana Azad Medical College, New Delhi, India.

Abstract
Little is known about the impact of concomitant vitamin D deficiency on bone mineral density in hyperthyroidism. Therefore, we evaluated bone mineral measures in vitamin D-deficient and sufficient patients with hyperthyroidism. Thirty newly diagnosed consecutive patients with hyperthyroidism were included. Blood samples were used for measurement of calcium, phosphate, alkaline phosphatase, 25-hydroxy vitamin D [25(OH) D], and parathyroid hormone (PTH). Bone mineral density (BMD) was measured at the hip, spine, and forearm. The patients were divided into vitamin D-deficient (<25nmol/L) and vitamin D-sufficient groups (>/=25nmol/L). Eight (26.6%) patients had 25(OH) D levels less than 25nmol/L, with mean+/-standard deviation (SD) level of 16.5+/-3.2 (vitamin D-deficient group 1), and the remainder had a mean+/-SD of 46.0+/-13.5nmol/L (vitamin D-sufficient group 2). Serum-intact PTH levels were significantly higher in group 1 compared with those in group 2 (31.2+/-16.3 vs 18.0+/-13.1pg/mL; p=0.041). In the vitamin D-deficient group, the mean BMD T-scores were in the osteoporotic range at hip and forearm (-2.65+/-1.13 and -3.04+/-1.3) and in the osteopenia range at lumbar spine (-1.83+/-1.71). However, in vitamin D-sufficient group, the mean BMD T-scores were in the osteopenia range (-1.64+/-1.0, -1.27+/-1.6, and -1.60+/-0.7) at hip, forearm, and lumbar spine, respectively. The mean BMD Z-scores were also significantly lower in vitamin D-deficient group compared with those in vitamin D-sufficient group. Finally, BMD values (gm/cm(2)) at the hip and forearm were significantly lower in the vitamin D-deficient group compared with those in the vitamin D-sufficient group. In conclusion, hyperthyroid patients with concomitant vitamin D deficiency had lower BMD compared with vitamin D-sufficient patients. Copyright © 2010 The International Society for Clinical Densitometry. Published by Elsevier Inc. All rights reserved.

PMID: 20663698

[vonneke]

http://ebm.rsmjournals.com/cgi/reprint/ ... 0.010014v1

Exp Biol Med (Maywood). 2010 Jul 28. [Epub ahead of print]

Vitamin D nutritional policy needs a vision for the future.

Norman AW, Bouillon R.

Department of Biochemistry and Division of Biomedical Sciences, University of California, Riverside, CA 92521, USA.

Abstract
Historically vitamin D is known to be essential for normal bone growth and quality, and thus appropriate dietary vitamin D supplementation can eliminate vitamin D deficiency childhood rickets and adult osteomalacia. In spite of many government and medical associations' worldwide guidelines for the reference daily intake (RDI) of vitamin D, scientists and nutritionists from many countries agree that at present about half of elderly North Americans and Western Europeans and probably also of the rest of the world are not receiving enough vitamin D to maintain healthy bone. In addition, over the past decade there has been a dramatic increase in our understanding of the many biological actions that result from vitamin D acting through its daughter steroid hormone, 1alpha,25-dihydroxyvitamin D(3) [1alpha,25(OH)(2)D(3)] in collaboration with its cognate vitamin D receptor (VDR). Consequently, evidence has accumulated that beside intestine and bone, there are five additional physiological systems where the VDR with 1alpha,25(OH)(2)D generates biological responses. These include the immune system (both the innate and adaptive), pancreas and metabolic homeostasis, heart-cardiovascular, muscle and brain systems as well as the control of the cell cycle, and thus of the disease process of cancer. Acting through the VDR, 1alpha,25(OH)(2)D(3) can produce a wide array of favorable biological effects that collectively are projected to contribute to the improvement of human health. Responsible medicine demands that worldwide vitamin D nutritional guidelines reflect current scientific knowledge about vitamin D's spectrum of activities. Thus, worldwide vitamin D nutritional policy is now at a crossroads. This paper presents several proposed policy changes with regard to the amount of vitamin D daily intake that if implemented will maximize vitamin D's contribution to reducing the frequency of many diseases, which would then increase the quality and longevity of life and significantly reduce the cost of medical care worldwide.

PMID: 20667908

[vonneke]

Vitamin D Is Effective In Reducing Frequency Of Many Diseases And Cost Of Medical Care :
:

http://www.medicalnewstoday.com/articles/197356.php

[vonneke]

Mayo Clin Proc. 2010 Aug;85(8):752-7; quiz 757-8.

Vitamin D deficiency in adults: when to test and how to treat.

Kennel KA, Drake MT, Hurley DL.

Division of Endocrinology, Mayo Clinic, Rochester, MN 55905, USA. hurley.daniel@mayo.edu

Abstract
Recent evidence for the nonskeletal effects of vitamin D, coupled with recognition that vitamin D deficiency is common, has revived interest in this hormone. Vitamin D is produced by skin exposed to ultraviolet B radiation or obtained from dietary sources, including supplements. Persons commonly at risk for vitamin D deficiency include those with inadequate sun exposure, limited oral intake, or impaired intestinal absorption. Vitamin D adequacy is best determined by measurement of the 25-hydroxyvitamin D concentration in the blood. Average daily vitamin D intake in the population at large and current dietary reference intake values are often inadequate to maintain optimal vitamin D levels. Clinicians may recommend supplementation but be unsure how to choose the optimal dose and type of vitamin D and how to use testing to monitor therapy. This review outlines strategies to prevent, diagnose, and treat vitamin D deficiency in adults.

PMID: 20675513

[vonneke]

Vitamin D Linked To Autoimmune And Cancer Disease Genes, Underscoring Risks Of Deficiency :

http://www.medicalnewstoday.com/articles/198024.php

[Jans]

Meer vitamine D kan in Nederland jaarlijks 25.000 levens sparen

2010 - Een verhoging van de gemiddelde vitamine D-spiegel in het bloed van 50 naar 100 tot 150 nmol/l zou het risico voor ernstige ziekten - daaronder talrijke soorten kanker, hart- en vaatziekten, diabetes, bacteriële en virale infecties, auto-immuunziekten, osteoporose, dementie en hartinsufficiëntie - met 50% verminderen. Bovendien zou het sterftecijfer bij deze ziekten 23% dalen. Tot deze op Nederland betrekking hebbende conclusie komen William Grant en Gert Schuitemaker in hun studie dat werd gepubliceerd in het vaktijdschrift 'Journal of Steroid Biochemistry and Molecular Biology' . In een vergelijkbaar onderzoek voor Duitsland stelt Armin Zittermann, hoofd van de studiecentrale hartchirurgie aan het hart- en diabetescentrum van Noordrijn-Westfalen, dat de kosten voor het Duitse gezondheidsbegrotingen met 37,5 miljard per jaar zouden kunnen worden verminderd bij een afdoende verzorging van de bevolking met vitamine D. Op basis van de actuele onderzoeksstand berekenen de onderzoekers in hun onderzoek aan de hand van het voorbeeld van Nederland de uitwerkingen van een verhoogde vitamine D-verzorging op het ziekte- en sterfterisico. Een gemiddelde vitamine D-spiegel van 100 tot 150 nmol/l geldt in de wetenschap als waardebereik waarbinnen vitamine D zijn positieve uitwerkingen optimaal kan ontplooien. Wanneer er voldoende zonneschijn is, kan bij blootstelling vitamine D in de huid worden aangemaakt. ‘Maar', zo stelt Gert Schuitemaker, ‘in de praktijk blijkt echter dat de dagelijkse voeding ook moet worden aangevuld met vitamine D-supplementen. De dagelijkse voeding levert onomstotelijk veel te weinig om dergelijke preventieve spiegels in het bloed te halen.' William Grant verbaast zich over de houding van overheden. ‘Het is verbazingwekkend, hoe weinig aandacht de overheid in haar informaties besteedt aan de talrijke wetenschappelijke bewijzen over de positieve werking die een geoptimaliseerde vitamine D-verzorging heeft op de gezondheid.' Volgens de wetenschapper zouden de Europese staten hun richtlijnen voor voedingssupplementen zodanig verder moeten ontwikkelen dat ze een hoger vitamine D-gehalte toestaan. Bovendien adviseert Grant gematigde bezonning in de openlucht of onder het solarium om te voorzien in de menselijke behoefte aan vitamine D. Samengevat kan worden gesteld dat een geoptimaliseerde vitamine D-spiegel het risico voor uiteenlopende, veel voorkomende ziekten verlaagt en voor de overheid aanzienlijke besparingen kan opleveren.

Bron:
Grant WB, Schuitemaker G. Health benefits of higher serum 25-hydroxyvitamin D levels in The Netherlands. J Steroid Biochem Mol Biol. 2010 Apr 14. [Epub ahead of print]

http://vitamine-d.nu/nieuws/7418/meer-v ... ens-sparen

http://www.ncbi.nlm.nih.gov/pubmed/20398763

[Martijn]

Tegenstrijdig met alle positieve berichten over vitamine D en gematigde bezonning, is dat tegenwoordig half Nederland zich insmeert met factor 50 o.i.d. (wat ook de vitamine D productie belemmert), omdat zonlicht zo gevaarlijk zou zijn. Je moet er natuurlijk wel voor zorgen dat je niet verbrandt, maar verder denk ik dat de voordelen van zonlicht opwegen tegen de nadelen, anders zouden we hier in Europa niet zo blank zijn. Waarschijnlijk door natuurlijke selectie hebben mensen in gebieden met veel zonlicht van een hoge kracht een donkere huid, en in gebieden met minder zonlicht/zonkracht juist een lichtere huid.