Vitamin A subgroups shaped an exploratory vitamin D finding in digestive tract cancer
A secondary trial analysis found a relapse-free survival difference in a selected vitamin A range; the subgroup choices were made after the fact.
Based on the published abstract. The full paper may contain additional methods, results and limitations.
The 30-second takeaway
In a selected middle-to-upper vitamin A subgroup, patients assigned vitamin D had better relapse-free survival than those assigned placebo. No benefit was detected in the lower or highest vitamin A ranges. Because researchers explored multiple cutoffs and grouped patients after the fact, this is a hypothesis about treatment differences, not an established way to choose supplementation.
The abstract describes several vitamin A cutoff schemes, with final groupings chosen post hoc. This makes the subgroup result exploratory and in need of confirmation.
What researchers found
5-year relapse-free survival
Vitamin D versus placebo in vitamin A deciles 6–8; HR for relapse or death 0.31 (95% CI 0.14–0.69), P = 0.004.
What the outcome captures
The main outcome combined cancer relapse and death. Relapse-free survival therefore describes remaining alive without relapse; it cannot be read as a result for cancer recurrence alone or for overall survival alone.
Why subgroup selection matters
Vitamin A was measured in blood, while vitamin D was the randomized treatment. Searching across different ways to divide vitamin A levels can reveal patterns, but this analysis did not establish a treatment-selection rule.
The original publication
Effect Modification by Serum Vitamin A Levels on the Association between Vitamin D and Relapse or Death in Patients with Digestive Tract Cancer.
Kohmura T, Ohdaira H, Suzuki Y et al.
Cancer Epidemiol Biomarkers Prev · 2026
- PubMed ID
- 41524587
- Record checked
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