British Journal of Nutrition

  • British Journal of Nutrition / Volume 107 / Issue 08 / April 2012, pp 1128-1137
  • Copyright © The Authors 2011. The online version of this article is published within an Open Access environment subject to the conditions of the Creative Commons Attribution-NonCommercial-ShareAlike licence <http://creativecommons.org/licenses/by-nc-sa/2.5/>. The written permission of Cambridge University Press must be obtained for commercial re-use.
  • DOI: http://dx.doi.org/10.1017/S0007114511004132 (About DOI), Published online: 07 September 2011
  • OPEN ACCESS

Metabolism and Metabolic Studies

Plasma appearance and disappearance of an oral dose of 25-hydroxyvitamin D2 in healthy adults

Kerry S. Jonesa1 c1, Inez Schoenmakersa2, Les J. C. Blucka2, Shujing Dinga2 and Ann Prenticea1a2

a1 MRC Keneba, MRC Unit, PO Box 273, Banjul, The Gambia

a2 MRC Human Nutrition Research, Elsie Widdowson Laboratory, Fulbourn Road, Cambridge CB1 9NL, UK

Abstract

25-Hydroxyvitamin D (25(OH)D) half-life is a potential biomarker for investigating vitamin D metabolism and requirements. We performed a pilot study to assess the approach and practical feasibility of measuring 25(OH)D half-life after an oral dose. A total of twelve healthy Gambian men aged 18–23 years were divided into two groups to investigate the rate and timing of (1) absorption and (2) plasma disappearance after an 80 nmol oral dose of 25(OH)D2. Fasting blood samples were collected at baseline and, in the first group, every 2 h post-dose for 12 h, at 24 h, 48 h and on day 15. In the second group, fasting blood samples were collected on days 3, 4, 5, 6, 9, 12, 15, 18 and 21. Urine was collected for 2 h after the first morning void at baseline and on day 15. 25(OH)D2 plasma concentration was measured by ultra-performance liquid chromatography-tandem MS/MS and corrected for baseline. Biomarkers of vitamin D, Ca and P metabolism were measured at baseline and on day 15. The peak plasma concentration of 25(OH)D2 was 9·6 (sd 0·9) nmol/l at 4·4 (sd 1·8) h. The terminal slope of 25(OH)D2 disappearance was identified to commence from day 6. The terminal half-life of plasma 25(OH)D2 was 13·4 (sd 2·7) d. There were no significant differences in plasma 25(OH)D3, total 1,25(OH)2D, parathyroid hormone, P, Ca and ionised Ca and urinary Ca and P between baseline and day 15 and between the two groups. The present study provides data on the plasma response to oral 25(OH)D2 that will underpin and contribute to the further development of studies to investigate 25(OH)D half-life.

(Received January 06 2011)

(Revised June 29 2011)

(Accepted June 29 2011)

(Online publication September 07 2011)

Correspondence:

c1 Corresponding author: Dr K. S. Jones, email kjones@mrc.gm

Footnotes

Abbreviations: 25(OH)D, 25-hydroxyvitamin D; DBP, vitamin D-binding protein; iCa, ionised calcium; LC, liquid chromatography; PTH, parathyroid hormone; uCa, urinary calcium; uCr, urinary creatinine; uP, urinary phosphate

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