Oral vitamin D3 supplementation for chronic plaque psoriasis: a randomized, double-blind, placebo-controlled trial

J Dermatolog Treat. 2018 Nov;29(7):648-657. doi: 10.1080/09546634.2018.1444728. Epub 2018 Mar 22.


Purpose: The management of psoriasis remains a challenge for dermatologist and patient. This study aimed to determine whether vitamin D3 supplementation improves psoriasis compared to placebo.

Materials and methods: In a randomized, doubled-blind, placebo-controlled trial, 101 participants ≥18 years with psoriasis were grouped by severity and allocated to 100,000 International Units (IU) vitamin D3/month for 12 months (200,000 IU at baseline; n = 67) or an identical placebo (n = 34). Psoriasis Area and Severity Index (PASI) and serum 25(OH)D concentrations were assessed at 3-monthly intervals. The primary outcome was the difference in PASI between groups over time. The relationship between 25(OH)D and PASI across the sample was also considered in a post hoc analysis.

Results: PASI did not differ between groups at any time (group F(1, 104) = 0.48, p = .49; group*time F(4, 384) = 0.26, p = .90). However, 25(OH)D increased in both groups, rendering these findings inconclusive. A significant inverse relationship existed between PASI and 25(OH)D, with elevation of 25(OH)D by up to 125 nmol/L associated with mild decreases in PASI (estimated range of decrease 0-2.6; p = .002).

Conclusions: A direct benefit of vitamin D3 supplementation for psoriasis could not be determined. However, these findings suggest a relationship between 25(OH)D and psoriasis severity, at least in some subgroups. Australian New Zealand Clinical Trials Registry #12611000648921.

Keywords: Vitamin D; psoriasis; randomized; supplementation.

Publication types

  • Randomized Controlled Trial

MeSH terms

  • Administration, Oral
  • Adult
  • Cholecalciferol / blood
  • Cholecalciferol / therapeutic use*
  • Chronic Disease
  • Dietary Supplements
  • Dose-Response Relationship, Drug
  • Double-Blind Method
  • Drug Administration Schedule
  • Female
  • Humans
  • Linear Models
  • Male
  • Middle Aged
  • Placebo Effect
  • Psoriasis / drug therapy*
  • Psoriasis / pathology
  • Severity of Illness Index


  • Cholecalciferol