Psoriasis and Vitamin D: A Systematic Review and Meta-Analysis

Abstract

Psoriasis is a chronic immune-dysregulated inflammatory disease and hypovitaminosis D is considered a risk factor. We conducted an online database search to review and meta-analyze the relationship between vitamin D, other bone metabolism parameters, and psoriasis. The efficacy of oral vitamin D supplementation in improving Psoriasis Area and Severity Index (PASI) was also evaluated. Non-original articles, case reports, and animal studies were excluded. Bias risk was assessed according to the Cochrane Collaboration’s tool and the Newcastle–Ottawa scale in randomized controlled trials (RCTs) and case–control studies, respectively. Unstandardized mean differences were used for data synthesis. Twenty-three studies reported serum 25 hydroxyvitamin D (25(OH)D) levels in 1876 psoriasis patients and 7532 controls. Psoriasis patients had significantly lower 25(OH)D levels than controls (21.0 ± 8.3 vs. 27.3 ± 9.8, p < 0.00001). Conversely, 450 psoriasis patients had lower levels of parathormone than 417 controls (38.7 ± 12.8 vs. 43.7 ± 16.5, p = 0.015). Four RCTs examined the effect of oral vitamin D supplementation on psoriasis for 173 patients and 160 patients were treated with placebo. No significant differences were found in PASI after 3, 6, and 12 months of supplementation. It is shown that 25(OH)D serum levels are significantly lower in psoriasis, but, although the granularity of RCT methodology may have influenced the pooled analysis, vitamin D supplementation did not seem to improve clinical manifestations.

Efficacy and safety of vitamin D supplementation on psoriasis: A systematic review and meta-analysis

“…In summary, despite the aforementioned shortcomings of this study, we report a latest meta-analysis, The results showed that, in terms of effectiveness, vitamin D supplementation failed to have a significant impact on the overall effectiveness evaluation of the PASI, DLQI, PDI and CRP, and therefore we are in agreement with the findings of Formisano [11] and Theodoridis et al [12] The difference is that in the subgroup analysis, vitamin D2 seems to be more effective than vitamin D3, and Asians seem to be more effective than Europeans, an information that should not be ignored; in terms of safety, no serious adverse effects were found, except for minor discomfort in very few cases, but we need to be cautious in our evaluation as the optimal dosage still needs to be explored. Nevertheless, in order to further investigate the efficacy and safety of vitamin D supplementation, we call for more well-designed, large-scale, prospective randomized studies in terms of optimal dosage, different populations, and different vitamin D types.…”

“…Several systematic reviews and meta-analyses of the efficacy of vitamin D supplementation in psoriasis have noted that supplementation has failed to show a significant effect [11,12]. However, it is important to note that the effectiveness conclusions of these studies were based solely on the PASI ignoring the shortcomings of the PASI itself and the impact of improvements in patients' quality of life on effectiveness [13].…”

Low Vitamin K Status in Patients with Psoriasis Vulgaris: A Pilot Study

“…The topic of vitamin D in PV has been widely studied, but the reports are still contradictory. There are studies that found significant vitamin D deficiency in patients with PV, debating whether this deficiency is a risk factor or a consequence of PV [51][52][53], but others have found no differences [54,55]; our results are in accordance with the last category. Moreover, our entire study population was found to have hypovitaminosis D, with the PV group having almost identical median values to those of the healthy subjects.…”

The 2023’s Growing Evidence Confirming the Relationship between Vitamin D and Autoimmune Diseases

“…A systematic review with a meta-analysis of 25(OH)D 3 serum concentrations of 1876 psoriatic patients and 7532 controls confirmed that hypovitaminosis D is more common in psoriasis than healthy conditions (paper published in the first edition of this Special Issue) [14].…”