Modifiers of the Absorption, Tissue Distribution and Activation of Vitamin D

• Applicant: Professorin Dr. Gabriele Stangl
• Subject Area: Nutritional Sciences
• Term: from 2016 to 2021
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 320705652

Despite the high prevalence of an insufficient vitamin D supply and the widespread use of isolated or food-based vitamin D for the prevention and therapy of vitamin D-deficiency, there is only scarce knowledge about the intestinal absorption, the tissue storage and the activation of orally administered vitamin D in the body. Moreover, factors that can modify all these processes and in consequence the bioavailability of vitamin D, are largely unknown. The current project aims to study the role of specific receptors and transporters for the intestinal absorption and the distribution of vitamin D in the body. Of special interest is the impact of the vitamin D status and dietary sterols on the metabolic balance of vitamin D. Balance trials and the use of orally applied deuterated vitamin D enable the characterization of vitamin D metabolism in transgenic and wildtype mice models in response to dietary vitamin D and presumed modifiers. The specific vitamin D metabolites will be identified and quantified by means of a high sensitive liquid chromatography-tandem mass spectrometry. The impact of the vitamin D status and the dietary sterols on the tissue-specific hydroxylation of vitamin D to 25-hydroxyvitamin D will be investigated in an ex vivo trial by use of radiolabeled vitamin D.

• DFG Programme: Research Grants