UV-B-irradiated button mushroom soup,
does it really help with Improved serum 25-hydroxyvitamin D status in adults with low vitamin D?
research showsThe grade is C with 50 points. In a three-arm five-week randomized trial analyzing 26 adults, the UV-B mushroom-soup group rose 3.9 nmol/L per week. Because no validated clinical-importance threshold was found, the standardized effect from week-five values was classified by statistical convention; the mushroom-placebo difference was large. The groups were very small, with 8 and 9 participants, and this was a blood-test result, not evidence on fractures or bone density.
ads claimBoth the mushroom and comparator supplement supplied D2. General D2-versus-D3 differences are background, not this trial's direct comparison. Ordinary mushrooms also differ from the UV-B product containing 491 micrograms D2 per 100 g. Mushroom Service donated product; Luxembourg doctoral funding and the Heinrich-Kircher Foundation also supported the work, and the authors declared no conflicts of interest. Verdict 729 is pending and unscored for a different species and claim.
Useful facts when choosing a product
- The mushrooms were deliberately exposed to 1.5 J/cm2 UV-B, raising measured vitamin D2 from below 1 to 491 micrograms per 100 g.
- Soup supplied 700 micrograms, 28,000 IU, D2 once weekly for four weeks. Mushroom fresh weight was adjusted to measured concentration, and a fixed gram dose was not confirmed.
- Mushrooms provide D2, which differs metabolically from the D3 common in supplements. Neither the low content of ordinary mushrooms nor the high content of irradiated mushrooms can be assigned to the other.
What the research actually shows
The three arms were UV-B mushroom soup, nonirradiated soup plus a D2 supplement, and nonirradiated soup plus placebo. Twenty-seven were recruited and 26 analyzed: 8 mushroom, 9 D2, and 9 placebo. Week-five 25OHD was 56.7+/-7.2, 58.0+/-11.2, and 28.7+/-8.7 nmol/L. From baselines of 34.0, 28.7, and 38.7, the mushroom change was +22.7 and placebo -10.0, a roughly 32.7-nmol/L difference in unadjusted mean changes, not an adjusted randomized-group effect estimate. DRKS00000195 specified 350 micrograms/week and 24 participants, whereas publication used 700 micrograms/week, recruited 27, and analyzed 26.
Why this is classified as C (50)
The effect was large by the statistical convention used because no validated clinical-importance threshold was found, but the endpoint was a blood-test surrogate. Registry-publication discrepancies, only 8 to 9 participants per arm, and unreported individual target attainment yield C with 50 points.
Counterpoint. The serum vitamin D increase is real. C marks the boundary between established absorption and untested clinical benefits such as fractures, bone density, or infection outcomes.
Rejudgment record. Editor ruling applied — Because no validated clinical-importance threshold was found, the standardized effect from final values was classified by statistical convention while registry-publication discrepancies, 8 to 9 participants per arm, and missing individual attainment rates were reflected
| Endpoint | S | Surrogate marker - laboratory or imaging measures |
| Replication | R1 | Single confirmatory trial |
| Independence | I1 | Mixed funding sources |
| Effect size | E+ | Meets the clinically important threshold |
The scoring table and the verdict agree (C).
Sub-claim grades by effect
This ingredient is marketed for several effects. A single overall grade blends strong and weak claims together, so each effect is graded separately here. The overall grade reflects the strongest disconfirming or core claim.
| Effect (sub-claim) | Grade | Basis |
|---|---|---|
| Improved serum 25OHD from UV-B-irradiated button mushroom soup | C | The prospectively registered trial was positive but measured only a blood surrogate. |
Cross-check — Codex and Claude
Evidence Table
| Study | Design | Sample | Funding | Endpoint | Result | Weight |
|---|---|---|---|---|---|---|
| Study 1 | Five-week three-arm single-blind randomized trial | 9 | Mushroom Service product donation, Luxembourg doctoral funding, and Heinrich-Kircher Foundation; authors declared no conflicts | Change in total serum 25OHD | Weekly slopes mushroom +3.9, 2.9 to 4.8, and D2 +4.7, 3.8 to 5.7; P=0.20 does not establish equivalence | Direct positive evidence with a large effect by statistical convention because no validated clinical-importance threshold was found |
Receipt — 2 References
All 2 cited sources were verified for existence at the original page (as of 2026-08-03).
Reviewed and approved: Chamgap Editorial Team · Approval date: 2026-08-03 · Corrections: none
Cite this verdict
[Chamgap] UV-B-irradiated button mushroom soup x improved vitamin D status — Evidence Grade C·50. 2 cited sources checked. Source: https://chamgap.com/en/verdicts/general/uvb-button-mushroom-soup-vitamin-d-status/ · CC BY 4.0CC BY 4.0 — free to use with attribution; do not distort grades, numbers, or verdict meaning.
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