Vitamine D

Vitamine D est désignée comme une vitamine liposoluble, bien qu’elle est avant tout une pré-hormone nécessaire pour beaucoup de fonctions de l’organisme.

Vitamine D est la vitamine du soleil car elle est produite dans l’organisme après une exposition au soleil de la peau (visage, bras, jambes etc…) sans crème solaire. En général une exposition au soleil de 15 à 20 minutes par jour suffit pour une bonne réserve en vitamine D.

Malheureusement les gens qui viennent dans les régions ou les jours sont nuageux ou avec beaucoup de air pollution ont souvent un manque de vitamine D.

Les effets les plus salutaires du soleil sont dérivés par l’action des rayonnements ultraviolet-B (UVB) qui sont responsables pour la production de la vitamine D dans la peau.

Certains aliments contiennent beaucoup de vitamine D comme les poissons gras (saumon et maquereau), céréales, huîtres, caviar, produits laitiers fortifiés et même les produits de soja. Généralement il est difficile de consommer assez de vitamine D par la nourriture et en plus certains poissons peuvent contenir des métaux lourds.

Une carence de vitamine D est très courant mais souvent négligée et peut résulter par :

Un manque d’exposition au soleil comme remarquer ci-dessus ou un manque de vitamine D dans l’alimentation
Maladies du foie et des reins
Malabsorption de la nourriture
Certain médicaments comme la phénytoine, le phénobarbital et la rifampine
Un excès de vitamine D est possible et s’appelle Hypervitaminose D ou vitamine D toxicité. Cette condition est très rare mais potentiellement dangereuse.

Vitamine D est facilement mesurée dans le sérum et le test le plus précis, simple et peu coûteux est le “25-hydroxy vitamine D”.

Besoin de matériel: Sérum (3ml)

Tests prévus:

25-Hydroxy-Vitamine D (Calcifédiol)
1,25-Dihydroxy-Vitamine D (Calcitriol)

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The Effect of Vitamin D on Cancer Incidence and Survival

(OMNS July 15, 2019) The results of a phase 2 randomized controlled trial (RCT) of high- vs. low-dose vitamin D3 supplementation for 139 patients with advanced colorectal cancer taking chemotherapy was recently reported in JAMA [Ng et al., 2019]. The high-dose vitamin D treatment was 8000 IU/d vitamin D3 for two weeks, then 4000 IU/d thereafter. The low-dose treatment group received 400 IU/d vitamin D3. The length of time before the disease worsened was 13 months in the high-dose treatment group and 11 months in the low-dose group. Further, high-dose vitamin D3 supplementation significantly reduced the risk of death by 36% (P = 0.02). In secondary analyses, the length of time before the disease worsened was significantly longer for patients in the treatment group who maintained a healthy weight, or had more metastatic sites.
The rate of diarrhea was 12% in the low-dose group, but only 1% in the high-dose group. This finding is consistent with the role of vitamin D in maintenance of gut mucosal barrier integrity.

Vitamin D Reduces Cancer Risk: Why Scientists Accept It but Physicians Do Not

(OMNS Feb 6 2019) The UVB-vitamin D-cancer hypothesis is nearly 40 years old [Garland, 1980]. There are 5293 publications with cancer and vitamin D or 25-hydroxyvitamin D [25(OH)D] in the title or abstract listed at pubmed.gov as of January 30, 2019. Nonetheless, this hypothesis has not been widely accepted; in fact, since the publication of the results for vitamin D supplementation for cancer in the VITamin D and OmegA-3 TriaL (VITAL) [Manson, 2019], support has been eroded further. As will be discussed here, the problem does not seem to be lack of evidence but, instead, the difference in how two cultures, the 'scientific' and the 'medical' communities, evaluate evidence.

Proven vaginal high-dose vitamin D3 recipes

Prof. Dr. med. Claus Schulte-Uebbing, Prof. Dr. med. Ingrid Gerhard and Doru Ioan Crăiut present proven vaginal high-dose vitamin D3 recipes for gynecological, urological and oncological practice.
New small studies have shown, that these recipes can be used for the treatment and prophylaxis of, among others, cervical dysplasia (CIN I), stress incontinence grade I, progesterone deficiency diseases (endometriosis, fibroids, adenomyosis) and e-deficiency colpitis.

Vitamin D deficiency affects older people

Vitamin D deficient older individuals are more likely to struggle with everyday tasks such as dressing or climbing stairs, according to a recent study.

Vitamin D Status and Severity of Clostridium difficile Infections: A Prospective Cohort Study in Hospitalized Adults.

Clostridium difficile is the most common cause of nosocomial diarrhea, affecting up to 10% of hospitalized patients.

Low Vitamin D Linked to Hepatitis B

Researcher from the Johann Wolfgang Goethe University Hospital in Frankfurt, Germany has find out, that Vitamin D deficiency might be a key player in hepatitis B (HBV) replication.

Low levels of 25-hydroxyvitamin D (25(OH)D3) predicted high levels of the virus and vice versa.

Beneficial effects of UV radiation other than via vitamin D production

Most of the positive effects of solar radiation are mediated via ultraviolet-B (UVB) induced production of vitamin D in skin. However, several other pathways may exist for the action of ultraviolet (UV) radiation on humans as focused on in this review. One is induction of cosmetic tanning (immediate pigment darkening, persistent pigment darkening and delayed tanning). UVB-induced, delayed tanning (increases melanin in skin after several days), acts as a sunscreen. Several human skin diseases, like psoriasis, vitiligo, atopic dermatitis and localized scleroderma, can be treated with solar radiation (heliotherapy) or artificial UV radiation (phototherapy). UV exposure can suppress the clinical symptoms of multiple sclerosis independently of vitamin D synthesis. Furthermore, UV generates nitric oxide (NO), which may reduce blood pressure and generally improve cardiovascular health. UVA-induced NO may also have antimicrobial effects and furthermore, act as a neurotransmitter. Finally, UV exposure may improve mood through the release of endorphins.

Low Vitamin D in U.S. Children linked to FDA’s Foot-Dragging on Sunscreen Standards

Researchers from a major medical center in New York have reported that 7 out of 10 U.S. children have low levels of vitamin D, placing them at higher risk for bone disorders, heart disease, and other health problems (Kumar 2009).

Causal Relationship between Obesity and Vitamin D Status: Bi-Directional Mendelian Randomization Analysis of Multiple Cohorts

Obesity is associated with vitamin D deficiency, and both are areas of active public health concern. We explored the causality and direction of the relationship between body mass index (BMI) and 25-hydroxyvitamin D [25(OH)D] using genetic markers as instrumental variables (IVs) in bi-directional Mendelian randomization (MR) analysis.

Vitamin D: More May Not Be Better; Benefits in Healthy Adults Wear Off at Higher Doses, Research Suggests

In recent years, healthy people have been bombarded by stories in the media and on health websites warning about the dangers of too-low vitamin D levels, and urging high doses of supplements to protect against everything from hypertension to hardening of the arteries to diabetes.

Mushrooms and Vitamin D

Mushrooms are the only vegetarian food that can make Vitamin D.

http://www.berkeleywellness.com/healthy-eating/nutrition/article/mushrooms-and-vitamin-d