Deposition in and release of vitamin D<sub>3</sub> from body fat: evidence for a storage site in the rat

Saul J. Rosenstreich; Clayton Rich; Wade Volwiler

doi:10.1172/JCI106538

¹Department of Medicine, University of Washington School of Medicine, and the Veterans Administration Hospital, Seattle, Washington 98105

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¹Department of Medicine, University of Washington School of Medicine, and the Veterans Administration Hospital, Seattle, Washington 98105

Find articles by Rich, C. in: JCI | PubMed | Google Scholar

¹Department of Medicine, University of Washington School of Medicine, and the Veterans Administration Hospital, Seattle, Washington 98105

Find articles by Volwiler, W. in: JCI | PubMed | Google Scholar

Published in Volume 50, Issue 3 on March 1, 1971
J Clin Invest. 1971;50(3):679–687. https://doi.org/10.1172/JCI106538.
© 1971 The American Society for Clinical Investigation

Published March 1, 1971 - Version history

Vitamin D in all body tissues was radio-labeled by supplementing completely vitamin D-deficient weanling rats with oral vitamin D₃-4-¹⁴C for 2 wk. All vitamin D was then withheld, and radioactivity and vitamin D content in a variety of organs and tissues were measured. Adipose tissue was found to contain by far the greatest quantity of radioactivity throughout the 3 month experimental period. Immediately after supplementation, half of the total radioactivity in adipose tissue corresponded to unaltered vitamin D₃, and the other half to polar metabolites and esters of vitamin D₃ and unidentified peak II. 1 month later there was approximately the same proportion but a decrease in the total quantity of each form. We conclude that adipose tissue is the major storage site for vitamin D₃ in its several forms. Unaltered vitamin D₃ was the principal storage form observed and presumably a source available for conversion to other metabolites during deprivation.