Format

Send to

Choose Destination
Nutrients. 2017 May 8;9(5). pii: E469. doi: 10.3390/nu9050469.

Improved Dietary Guidelines for Vitamin D: Application of Individual Participant Data (IPD)-Level Meta-Regression Analyses.

Author information

1
Cork Centre for Vitamin D and Nutrition Research, School of Food and Nutritional Sciences, University College Cork, Cork T12 Y337, Ireland. k.cashman@ucc.ie.
2
Department of Medicine, University College Cork, Cork T12 DFK4, Ireland. k.cashman@ucc.ie.
3
Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Frederiksberg C DK-1958, Denmark. ritz@nexs.ku.dk.
4
Cork Centre for Vitamin D and Nutrition Research, School of Food and Nutritional Sciences, University College Cork, Cork T12 Y337, Ireland. m.kiely@ucc.ie.
5
Irish Centre for Fetal and Neonatal Translational Research (INFANT), University College Cork, Cork T12 DFK4, Ireland. m.kiely@ucc.ie.
6
Cork Centre for Vitamin D and Nutrition Research, School of Food and Nutritional Sciences, University College Cork, Cork T12 Y337, Ireland.

Abstract

Dietary Reference Values (DRVs) for vitamin D have a key role in the prevention of vitamin D deficiency. However, despite adopting similar risk assessment protocols, estimates from authoritative agencies over the last 6 years have been diverse. This may have arisen from diverse approaches to data analysis. Modelling strategies for pooling of individual subject data from cognate vitamin D randomized controlled trials (RCTs) are likely to provide the most appropriate DRV estimates. Thus, the objective of the present work was to undertake the first-ever individual participant data (IPD)-level meta-regression, which is increasingly recognized as best practice, from seven winter-based RCTs (with 882 participants ranging in age from 4 to 90 years) of the vitamin D intake-serum 25-hydroxyvitamin D (25(OH)D) dose-response. Our IPD-derived estimates of vitamin D intakes required to maintain 97.5% of 25(OH)D concentrations >25, 30, and 50 nmol/L across the population are 10, 13, and 26 µg/day, respectively. In contrast, standard meta-regression analyses with aggregate data (as used by several agencies in recent years) from the same RCTs estimated that a vitamin D intake requirement of 14 µg/day would maintain 97.5% of 25(OH)D >50 nmol/L. These first IPD-derived estimates offer improved dietary recommendations for vitamin D because the underpinning modeling captures the between-person variability in response of serum 25(OH)D to vitamin D intake.

KEYWORDS:

DRV; EAR; Individual Participant Data-level meta-regression analyses; RDA; vitamin D recommendations

PMID:
28481259
PMCID:
PMC5452199
DOI:
10.3390/nu9050469
[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for Multidisciplinary Digital Publishing Institute (MDPI) Icon for PubMed Central
Loading ...
Support Center