Source of Publication
Current Developments in Nutrition
© 2019 American Society for Nutrition. The status of vitamin D is determined mainly by its formation in skin by the photochemical action of solar UVB light (wavelength 290-320 nm) on the precursor 7-dehydrocholesterol. Because of seasonal variation in intensity of solar UV light, vitamin D status falls in winter and rises in summer. It has been presumed that there is no functional store of vitamin D. Thus, to avoid deficiency, a nutritional supply would be required in winter. However, there is now evidence that the main circulating metabolite of vitamin D, 25-hydroxyvitamin D, accumulates in skeletal muscle cells, which provide a functional store during the winter months. The mechanism is mediated by muscle cell uptake of circulating vitamin D-binding protein (DBP) through a megalin-cubilin membrane transport process. DBP then binds to cytoplasmic actin to provide an array of high-affinity binding sites for 25-hydroxyvitamin D [25(OH)D]. The repeated passage of 25(OH)D into and out of muscle cells would account for its long residence time in blood.
Oxford University Press
Medicine and Health Sciences
25-hydroxyvitamin D, muscle, seasonal variation, ultraviolet light, Vitamin D status, Vitamin D-binding protein
Creative Commons License
This work is licensed under a Creative Commons Attribution-Noncommercial 4.0 License
Mason, Rebecca S.; Rybchyn, Mark S.; Abboud, Myriam; Brennan-Speranza, Tara C.; and Fraser, David R., "The Role of Skeletal Muscle in Maintaining Vitamin D Status in Winter" (2019). All Works. 3588.
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Open Access Type
Gold: This publication is openly available in an open access journal/series