Written by Tabish Mehraj, PhD. Results of this retrospective multicenter study show that 26 out of 30 patients (87%) experiencing chemotherapy-associated skin toxicity or radiation dermatitis reported symptom relief improvement within 10 days of receiving 100,000 IU of oral vitamin D administration.

Severe skin-related issues can occur as a result of cancer treatment and may cause inflammation. In some cases, these toxic effects may require interruption or modification of anticancer therapy. Previous experimental studies and small clinical reports have suggested that high-dose vitamin D may have anti-inflammatory and immunomodulatory effects that could help reduce treatment-related skin injury. However, limited clinical evidence has been reported in patients receiving cancer therapy. This retrospective multicenter case series evaluated the clinical response, safety, and time to improvement following high-dose oral vitamin D (hdVD) administration in patients with toxic erythema of chemotherapy (TEC) or acute radiation dermatitis (ARD).

In this study, researchers reviewed medical records from three academic medical centers and identified 33 patients who had received one or two oral doses of 100,000 IU of vitamin D between December 2021 and January 2024. Patients had either chemotherapy-associated skin toxicity or radiation dermatitis and had at least 10 days of follow-up. 28 patients (85%) had TEC, while five (15%) had ARD. The average age was 60.9 years, and 58% of participants were female. The primary outcomes were patient-reported symptom relief and clinician-assessed improvement in erythema. Changes in serum calcium and the ability to continue anticancer therapy were also assessed.

Results/ Key Findings:

• Symptom relief: 26 of 30 patients (87%) reported improvement within 10 days, with a median time to improvement of 5 days overall and 3 days among inpatients.
• Erythema improved: The mean Likert erythema score decreased from 4.36 at baseline to 3.17 on day 5 and 2.21 on day 10.
• Continuation of cancer treatment: 24 of 33 patients (73%) continued anticancer therapy without interruption, while 4 patients (12%) discontinued treatment because of skin toxicity.
• Recurrence: 3 patients developed recurrent TEC following subsequent chemotherapy; 1 improved rapidly after repeat hdVD.
• Safety: No treatment-related adverse events or meaningful changes in serum calcium were reported; among 13 patients with post-treatment vitamin D measurements, all remained within the normal range.

Strengths of the study include its multicenter design and the inclusion of patients with different chemotherapy- and radiation-associated skin manifestations. The investigators assessed both subjective symptoms and objective changes in erythema rather than relying on a single outcome. The study also incorporated safety laboratory monitoring and examined whether patients could continue anticancer therapy, providing clinically relevant information. In addition, the study expanded on earlier small case reports and series by evaluating a larger cohort across three academic institutions. Several limitations should be considered when interpreting the findings. The retrospective design means the researchers could identify an association between hdVD treatment and subsequent improvement, but could not establish that vitamin D caused the improvement. There was no placebo or untreated control group, making it impossible to determine how much of the observed recovery reflected the natural course of the skin toxicity or other treatments. Most patients also received concurrent supportive dermatologic therapy, with topical corticosteroids being particularly common. This creates an additional challenge in isolating the specific contribution of vitamin D. The investigators also acknowledged variable follow-up, potential selection bias, incomplete laboratory data, and the use of a novel, non-validated 5-point Likert scale for erythema assessment. The ARD subgroup was particularly small, with only five patients, limiting conclusions about radiation dermatitis specifically.

Overall, this study found that high-dose oral vitamin D was associated with relatively rapid improvement in symptoms and skin erythema, with no treatment-related adverse events observed during the short follow-up period. However, because the study was uncontrolled and retrospective, these findings should be considered preliminary. Prospective randomized controlled trials with standardized outcome measures, longer follow-up, and protocolized safety monitoring are needed to determine whether hdVD is an effective treatment for chemotherapy- and radiation-associated skin toxicities and to establish the optimal dose and long-term safety.

References:

1. Patil, M. K., Sakunchotpanit, G., Toulmin, S. A., Braun, N., Milosavljevic, S., Ezzeddine, F. L., … & Iriarte, C. (2026). High-Dose Oral Vitamin D for Toxic Effects of the Skin Associated with Chemotherapy and Radiation. JAMA Dermatology.