The Clinical Effect of Oral Vitamin D2 Supplementation on Psoriasis: A Double-Blind, Randomized, Placebo-Controlled Study

Abstract EN

Background.

There are limited randomized controlled trials of oral vitamin D supplementation in psoriasis, especially in Asia, and the results are inconclusive.

Objective.

To investigate the clinical effect of oral vitamin D supplementation on psoriasis.

Methods.

Patients with psoriasis were randomized to receive vitamin D2 60,000 IU or similar-looking placebo pills once every 2 weeks for 6 months.

The primary outcome was improvement of the Psoriasis Area and Severity Index (PASI) score at 3 and 6 months after treatment.

Serum levels of 25(OH)D, calcium, phosphate, parathyroid hormone, and C-reactive protein and adverse events were monitored.

The chi-square test, Fisher’s exact test, Student’s t-test, and Spearman’s correlation analysis were used in statistical analysis.

Results.

Of 50 subjects screened, 45 were eligible and randomized to the oral vitamin D2 group (n=23) or placebo group (n=22).

At enrollment, the mean PASI score was 4.45, and 26.7% of patients had vitamin D deficiency.

At 3 months, the oral vitamin D2 group had significantly higher PASI improvement than the placebo group (mean PASI improvement: 1.43 versus [vs.] -0.33, p-value=0.034; mean %PASI improvement: 34.21% vs.

-1.85%, p-value=0.039).

The mean serum 25(OH)D level was significantly higher in the oral vitamin D group than in the placebo group (27.4 vs.

22.4 ng/mL, p-value=0.029).

Serum 25(OH)D concentrations were significantly inversely correlated with PASI scores at the 6-month follow-up.

No major adverse event was observed overall.

Conclusion.

Oral vitamin D2 supplementation in patients with psoriasis increased the serum vitamin D level and significantly improved the treatment outcome without increasing adverse events.

Trial Registration.

This trial is registered with Thai Clinical Trials Registry TCTR20180613001.