Hypovitaminosis D is Associated with Psoriasis: A Systematic Review and Meta- Analysis

  • Siwadon Pitukweerakul
  • Subhanudh Thavaraputta
  • Sittichoke Prachuapthunyachart
  • Rudruidee Karnchanasorn
Keywords: cholecalciferol, skin diseases, vitamin D, psoriasis, meta-analysis



Psoriasis is a chronic inflammatory and immunemediated
skin disease that affects over 7.2 million U.S. adults. Current
treatment has improved clinical outcomes. Vitamin D is believed to
affect the proliferation and regeneration of keratinocytes; therefore,
its deficiency is a possible risk factor; however, there is still no definite
evidence. The objective of this study was to synthesize existing data
on the relationship between hypovitaminosis D and psoriasis.


A meta-analysis of relevant studies was conducted by
doing a comprehensive search in the MEDLINE, EMBASE, and the
Cochrane Central Register through July 2018 to identify relevant
cohort studies and to assess serum 25-hydroxyvitamin D (25(OH)
D) levels in adults with psoriasis. The primary outcome was the mean
difference in serum 25(OH)D level between psoriatic patients and


The initial search identified 107 articles. Only ten studies
met the criteria for full-paper review. Meta-analysis was conducted
from ten prospective cohort studies involving 6,217 controls and 693
cases. The pooled mean difference in serum 25(OH)D level between
psoriatic patients and controls was -6.13 ng/ml (95% CI, -10.93 to
-1.32, p-value = 0.01). The between-study heterogeneity (I2) was
98%, p < 0.00001.


Our meta-analysis was the first study to establish the
relation between vitamin D and psoriasis. The result found a significant
relationship between low 25(OH) D levels and psoriasis, but did
not establish a causal relationship. Further studies will be required
to establish whether vitamin D supplementation benefits patients
with psoriasis.

Original Research