La vitamine D ne fait pas à maigrir

[Nutrimuscle-Conseils]

Supplementation with cholecalciferol does not result in weight reduction in overweight and obese subjects

European Journal of Endocrinology, Vol 159, Issue 6, 675-684

Objective: Investigate whether cholecalciferol supplementation leads to weight loss in overweight and obese adults.

Design: Randomized double blind clinical trial with 20 000 IU cholecalciferol twice a week, or 20 000 IU once a week plus placebo, or placebo twice a week, for 12 months. All subjects were given 500 mg calcium supplementation.

Methods: Four hundred and forty five healthy, overweight, and obese men and women (age 21–70 years, body mass index (BMI) 28.0–47.0 kg/m2). Body weight, fatness, and fat distribution parameters were measured by dual-energy X-ray absorptiometry and anthropometry, blood samples and 24-h urinary samples were collected.

Results: At baseline, there were no significant differences between the groups, but there was a significant inverse relation between serum 25-hydroxyvitamin D (25(OH)D) levels and BMI, and a significant positive association between calorie intake and BMI. Three hundred and thirty four subjects completed the study. During the study, there was no significant change in weight, waist-to-hip ratio (WHR) or percentage body fat in any of the groups, nor between them. Parathyroid hormone decreased and 25(OH)D increased significantly in both groups receiving cholecalciferol, and serum levels of 25(OH)D stabilized after 3 months. Serum calcium was unchanged in all groups. Urinary calcium excretion increased in all groups, but there was no significant difference between the groups. Weekly dosage of 20 000–40 000 IU cholecalciferol for 12 months was associated with a low risk of adverse effects, at least in overweight and obese adults living at latitude 70° N.

Conclusion: Significant weight reduction in overweight and obese subjects is unlikely to occur with cholecalciferol supplementation.

[Persephone]

Je viens de prendre un sacré coup au moral

[Persephone]

Reste qu'avec 500mg de calcium en plus de l'alimentation, c'est-à-dire un apport total important, et une bonne absorption (grâce à la vitamine D), il n'y a malgré tout pas eu de perte de poids.

Sachant que de telles doses se sont déjà montrées efficaces avec un régime hypocalorique, je ne pense pas qu'on puisse dire que la vitamine D est inefficace. Elle l'est peut-être à elle seule, comme le calcium. Mais dans le cadre d'un régime, il reste à déterminer s'il y a un bénéfice ou non.

[Nutrimuscle-Conseils]

ils s'attaquent à des sujets difficiles
j'ai l'impression que la vitamine D a surtout un impact santé plus que performance

[le-chêne]

j'ai l'impression que la vitamine D a surtout un impact santé plus que performance

Il y a des vitamines qui améliorent les performances?

[Persephone]

j'ai l'impression que la vitamine D a surtout un impact santé plus que performance

C'est certain.
C'est toujours ça de pris.
Et puis les performances quand on est malade ou avec le cancer, c'est assez moyen.

[Persephone]

Vitamin D deficiency is the cause of common obesity

Common obesity is associated with the metabolic syndrome and can be distinguished from secondary obesity and from rare forms of monogenic and polygenic obesity.

There is evidence for a central control mechanism which maintains body-weight to a set-point by the regulation of energy intake and energy expenditure through homeostatic pathways. It is suggested in this paper that common obesity occurs when the set-point is raised and that accumulation of fat mass functions to increase body size.

In addition, it is suggested that the phenotypic metabolic and physiological changes observed as the metabolic syndrome, including hypertension and insulin resistance, could result from a winter metabolism which increases thermogenic capacity. Common obesity and the metabolic syndrome may therefore result from an anomalous adaptive winter response. The stimulus for the winter response is proposed to be a fall in vitamin D.

It is here proposed that a fall in vitamin D in the form of circulating calcidiol is the stimulus for the winter response, which consists of an accumulation of fat mass (obesity) and the induction of a winter metabolism (the metabolic syndrome).

http://www.ncbi.nlm.nih.gov/pubmed/19054627



Papier peu intéressant, j'en conçois, mais c'est vrai qu'on oublie que la vitamine D joue un rôle dans la sensibilité à l'insuline et qu'elle influe probablement sur la leptine et la ghréline.
En somme, même si le bénéfice sur la perte de poids n'est pas direct, il y un certain de nombres de facteurs indirects qu'elle influence.
Et pour l'instant cela reste difficile de tirer tout cela au clair.

[Persephone]

Une autre review qui soulève la question:

Should we be concerned about the vitamin D status of athletes?

A surprisingly high prevalence of vitamin D insufficiency and deficiency has recently been reported worldwide. Although very little is known about vitamin D status among athletes, a few studies suggest that poor vitamin D status is also a problem in athletic populations. It is well recognized that vitamin D is necessary for optimal bone health, but emerging evidence is finding that vitamin D deficiency increases the risk of autoimmune diseases and nonskeletal chronic diseases and can also have a profound effect on human immunity, inflammation, and muscle function (in the elderly). Thus, it is likely that compromised vitamin D status can affect an athlete's overall health and ability to train (i.e., by affecting bone health, innate immunity, and exercise-related immunity and inflammation).


http://www.ncbi.nlm.nih.gov/pubmed/18458363

[Nutrimuscle-Conseils]

Il y a des vitamines qui améliorent les performances?

il s'agit plus du magnésium, calcium ou vitamines E et C qui sont étudiés chez le sportif

[le-chêne]

Extrait mdm 250 vitamines D et muscles
Par michael gundill et Florence Ghibellini

Dans les muscles,nous avons des récepteurs a la vitamine D, ce qui veut dire que cette vitamine possede un impact plus ou moins important sur ces derniers.D'ailleurs cher les rats dont la génétique a été modifiée pour qu'ils ne produisent pas de recepteurs a la vitamine D , les muscles sont fortement atrophiés par rapport aux rats normaux.De fait, une carence en vitamine D est associée a une hausse de niveau de calcium dans nos muscles.Ceci n'est jamais bon , car le calcium est toxique pour nos fibres musculaires.Un niveau bas de vitamine D est aussi associé a une hausse de parathormone (PTH), qui est catabolisante pour le muscle tout en favorisant l'accumulation graisseuse.Bref meme si la vitamine D n'est probablement pas un régulateur primordial pour le muscle, elle joue totu de meme un second role important