Predictors of 25(OH)D half-life and plasma 25(OH)D concentration in The Gambia and the UK
Summary Predictors of 25(OH)D 3 half-life were factors associated with vitamin D metabolism, but were different between people in The Gambia and the UK. Country was the strongest predictor of plasma 25(OH)D concentration, probably as a marker of UVB exposure. 25(OH)D 3 half-life may be applied as a...
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Published in | Osteoporosis international Vol. 26; no. 3; pp. 1137 - 1146 |
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Main Authors | , , , , , |
Format | Journal Article |
Language | English |
Published |
London
Springer London
01.03.2015
Springer Nature B.V |
Subjects | |
Online Access | Get full text |
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Summary: | Summary
Predictors of 25(OH)D
3
half-life were factors associated with vitamin D metabolism, but were different between people in The Gambia and the UK. Country was the strongest predictor of plasma 25(OH)D concentration, probably as a marker of UVB exposure. 25(OH)D
3
half-life may be applied as a tool to investigate vitamin D expenditure.
Introduction
The aim of this study was to investigate predictors of 25(OH)D
3
half-life and plasma 25(OH)D concentration.
Methods
Plasma half-life of an oral tracer dose of deuterated-25(OH)D
3
was measured in healthy men aged 24–39 years, resident in The Gambia, West Africa (
n
= 18) and in the UK during the winter (
n
= 18), countries that differ in calcium intake and vitamin D status. Plasma and urinary markers of vitamin D, calcium, phosphate and bone metabolism, nutrient intakes and anthropometry were measured.
Results
Normally distributed data are presented as mean (SD) and non-normal data as geometric mean (95 % CI). Gambian compared to UK men had higher plasma concentrations of 25(OH)D (69 (13) vs. 29 (11) nmol/L;
P
< 0.0001); 1,25(OH)
2
D (181 (165, 197) vs. 120 (109, 132) pmol/L;
P
< 0.01); and parathyroid hormone (PTH) (50 (42, 60) vs. 33 (27, 39);
P
< 0.0001). There was no difference in 25(OH)D
3
half-life (14.7 (3.5) days vs. 15.6 (2.5) days) between countries (
P
= 0.2). In multivariate analyses, 25(OH)D, 1,25(OH)
2
D, vitamin D binding protein and albumin-adjusted calcium (Ca
alb
) explained 79 % of variance in 25(OH)D
3
half-life in Gambians, but no significant predictors were found in UK participants. For the countries combined, Ca
alb
, PTH and plasma phosphate explained 39 % of half-life variability. 1,25(OH)
2
D, weight, PTH and country explained 81 % of variability in 25(OH)D concentration; however, country alone explained 74 %.
Conclusion
Factors known to affect 25(OH)D metabolism predict 25(OH)D
3
half-life, but these differed between countries. Country predicted 25(OH)D, probably as a proxy measure for UVB exposure and vitamin D supply. This study supports the use of 25(OH)D half-life to investigate vitamin D metabolism. |
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Bibliography: | ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 0937-941X 1433-2965 |
DOI: | 10.1007/s00198-014-2905-0 |