A narrative review asks why vitamin D trials leave basic questions unresolved
The author argues for changes in trial design, but this review does not provide a new pooled estimate of vitamin D’s benefits or establish a blood-level target.
Based on the published abstract. The full paper may contain additional methods, results and limitations.
The 30-second takeaway
This article examines why vitamin D research has not settled basic questions about deficiency and disease prevention. The author argues that many trials enrolled people who already had adequate levels and were poorly suited to detect small effects. These are arguments about interpreting and designing research, rather than new trial evidence of benefit.
The abstract provides no systematic search methods, study-level results or pooled effect estimates. Its broad claims about previous trials and possible benefits cannot be independently assessed from this summary.
Unresolved findings
The review describes large trials that did not find significant disease-prevention effects while mentioning possible benefits for selected outcomes. Without the underlying comparisons or numerical estimates, the abstract cannot show how convincing those possible benefits are.
Research proposals
The author proposes recruiting people with low blood levels and making future trials more comparable. These proposals identify research questions; the article does not test whether the suggested designs would produce different clinical outcomes.
The original publication
Why did we end up having so few vitamin D answers and what can we do about it? A provocative and narrative review.
Jorde R
J Steroid Biochem Mol Biol · 2026
- PubMed ID
- 41218688
- Record checked
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