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24.09.2012, 23:35

Interessante Hypothese:

Med Hypotheses. 2009 Mar;72(3):314-21. Epub 2008 Dec 2.
Vitamin D deficiency is the cause of common obesity.
Foss YJ.
Caterham on the Hill, Caterham, Surrey, UK.

Zitat:

"(...) 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. Larger body size confers a survival advantage in the cold ambient temperatures and food scarcity of the winter climate by reducing surface area to volume ratio and by providing an energy store in the form of fat mass. 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. The synthesis of vitamin D is dependent upon the absorption of radiation in the ultraviolet-B range of sunlight. At ground level at mid-latitudes, UV-B radiation falls in the autumn and becomes negligible in winter. It has previously been proposed that vitamin D evolved in primitive organisms as a UV-B sensitive photoreceptor with the function of signaling changes in sunlight intensity. 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). Vitamin D deficiency can account for the secular trends in the prevalence of obesity and for individual differences in its onset and severity. It may be possible to reverse the increasing prevalence of obesity by improving vitamin D status."

Sotte die Hypothese tragfähig sein, dann müßte man die Tendenz zum Aufbau von überflüssigen Pfunden in der kalten Jahreszeit verhindern können, indem man den 25OHD-Spiegel gezielt auf dem Sommerniveau hält.... .