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Rapid normalization of vitamin D levels: a meta-analysis
J Dayre McNally1, Klevis Iliriani2, Supichaya Pojsupap3
1Department of Pediatrics, Faculty of Medicine, University of Ottawa, Children's Hospital of Eastern Ontario, Ottawa, Ontario, Canada; Research Institute, Children's Hospital of Eastern Ontario, Ottawa, Ontario, Canada; dmcnally@cheo.on.ca.
Pediatrics
|December 17, 2014
Summary
High-dose vitamin D loading therapy effectively normalizes levels in deficient individuals. Doses exceeding 300,000 IU should be avoided pending further safety trials.
Area of Science:
- Pediatric critical care
- Endocrinology
- Nutritional science
Background:
- Vitamin D deficiency is a potential risk factor in severe illness.
- The effectiveness of high-dose vitamin D for rapid normalization is not well-established.
Purpose of the Study:
- To systematically review pediatric trials on high-dose vitamin D.
- To evaluate 25-hydroxyvitamin D (25[OH]D) response and factors influencing final levels.
Main Methods:
- Systematic review of Medline, Embase, and Cochrane trials.
- Inclusion of studies administering high-dose ergocalciferol or cholecalciferol (≥1000 IU).
- Independent data extraction and verification by two reviewers.
Main Results:
- Loading therapy (>50,000 IU) achieved 25(OH)D levels >75 nmol/L in most studies.
- Daily doses near the Tolerable Upper Intake Level (1000-4000 IU) were less effective for rapid normalization.
- Meta-regression identified baseline 25(OH)D, regimen, dose, age, and time as key factors.
- Hypercalcemia risk increased with doses >400,000 IU; loading doses <400,000 IU showed no increased risk.
Conclusions:
- Loading therapy, tailored to disease status, baseline 25(OH)D, and age/weight, is optimal for rapid vitamin D normalization.
- Avoid loading doses >300,000 IU until further risk-benefit trials are available.
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