High-dose vitamin D was followed by rapid settling of chemotherapy and radiation skin toxicity in a small series

Design

Retrospective multicentre case series

Population

33 patients with toxic erythema of chemotherapy or acute radiation dermatitis

Primary outcome

Time to symptomatic relief and clinician-rated erythema

Effect

Relief within 10 days in 26/30 (87%); erythema score 4.36 → 2.21 by day 10

Three US academic centres reviewed 33 patients given one or two oral doses of 100,000 IU of vitamin D for toxic erythema of chemotherapy (28) or acute radiation dermatitis (5) between late 2021 and early 2024.

Of 30 patients who reported on symptoms, 26 (87%) described relief within ten days; median time to improvement was five days. Clinician-rated erythema fell from about 4.4 to 2.2 on a five-point scale by day ten. Serum calcium did not change meaningfully, no treatment-related adverse events were recorded, and 73% continued anticancer treatment without interruption.

These reactions often improve on their own once the triggering drug cycle passes, and there was no comparison group, so the series cannot show that vitamin D caused the improvement. It is a reason for a randomised trial, not for adding high-dose vitamin D to supportive care routinely. It was published in September 2026.

• Keep managing toxic erythema of chemotherapy with established supportive care and liaison with oncology.
• Treat high-dose vitamin D here as investigational; this series had no control group.
• If a patient has already received it, check calcium and document the response.
• Watch for a randomised trial before changing practice.

Why it matters

A cheap, oral option for reactions that interrupt cancer treatment is worth testing properly.

Don't overread it

Without a control group, improvement that would have happened anyway cannot be separated from any drug effect.

The statistics, in plain English

Percentages from a case series describe what happened to these patients but not what would have happened without treatment. Small numbers (33) mean one or two patients change the percentages noticeably.

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