Comparison of vitamin D2 and vitamin D3 supplementation in raising serum 25-hydroxyvitamin D status: a systematic review and meta-analysis.
Level 1 - systematic review of randomized trials
Systematic review and meta-analysis of randomized controlled trials
PubMed 22552031 · doi:10.3945/ajcn.111.031070
What was done
Systematic review and meta-analysis of randomized controlled trials directly comparing the effects of vitamin D2 and vitamin D3 supplementation on serum 25-hydroxyvitamin D concentrations in adults. Searches were conducted from January 1966 to July 2011 across ISI Web of Knowledge, the Cochrane Clinical Trials Registry, ISRCTN register, and clinicaltrials.gov for published and unpublished trials.
What was found
Vitamin D3 supplementation produced a significantly greater increase in serum 25-hydroxyvitamin D concentrations compared to vitamin D2 (P = 0.001). When evaluated by dosage frequency, vitamin D3 was significantly superior when given as a bolus dose (P = 0.0002), but the significant difference was lost with daily supplementation. Quantitative effect estimates, confidence intervals, and study counts were not reported in the abstract.
Why it matters
This review indicates that vitamin D3 is generally more efficacious than vitamin D2 at raising serum 25-hydroxyvitamin D, with the advantage driven by bolus administration rather than daily dosing.
Limits
The abstract does not state the number of included trials, total sample size, or numerical effect sizes with confidence intervals. The analysis was also unable to assess outcomes across age, sex, ethnicity, or administration routes such as oral versus intramuscular.
Cited by
- supports Vitamin D2 is less effective at raising vitamin D status than vitamin D3.