Vitamin D supplementation does not significantly help psoriasis

According to new research, the efficacy and safety of vitamin D supplementation in the treatment of psoriasis cannot be determined due to nonsignificant findings.¹

According to the World Health Organization, more than 100 million people worldwide suffer from psoriasis. About 78% – 90% of patients with psoriasis have mild to moderate skin lesions. Vitamin D has been used to treat psoriasis since 1985 – ever since researchers discovered that people with psoriasis were deficient in vitamin D. Still, it is controversial whether vitamin D helps treat psoriasis.²

Vitamin D comes in 2 forms – ergocalciferol (vitamin D2) and cholecalciferol (vitamin D3). While Vitamin D2 is obtained from plants, Vitamin D3 is obtained from animals.¹ New research suggests that vitamin D2 may possibly help psoriasis patients more than vitamin D3, although treatment is not significant.

A new systematic review and meta-analysis led by Qianqian Dai, of the department of dermatology at Tianjin University of Traditional Chinese Medicine in Hefei, China, combined the findings of randomized controlled trials testing vitamin D supplementation for psoriasis to evaluate its effectiveness. Demanded to analyze. and safety. After searching multiple databases, the team selected 4 studies with a total of 333 patients. The investigator examined the change values ​​in psoriasis area and severity index at 3 months, 6 months and at the end of follow-up.

“Three of the publicly available RCTs failed to produce significant efficacy, and these studies that found ineffectiveness showed small changes that were thought to be due to other confounding factors rather than vitamin D supplementation,” the researchers wrote. Were impressed.”

Over 3 months, the investigators examined 206 patients (11 in the experimental group and 96 in the control group). The random effects model demonstrated that taking vitamin D for 3 months did not significantly affect the value of change in psoriasis area and severity index (-1.18; 95% CI, -2.35 – 0.00); Why = .05).

Over 6 months, 3 studies with 205 patients (109 in the experimental group and 96 in the control group). This time, the random effects model demonstrated that taking vitamin D supplementation at 6 months could significantly influence the value of change in psoriasis area and severity index (- 1.14; 95% CI, -2.26 to – 0.02; Why = .05).” However, there was no significant discrepancy in diversity (Yo2 = 0%, Why = .64).

In follow-up, 4 studies with 328 patients (169 in the experimental group and 159 in the placebo group) showed that vitamin D supplementation did not significantly affect the value of the change in psoriasis area and severity index. The findings also found that, when treating psoriasis, vitamin D supplementation (- 1.44; 95% CI, -2.75 to – 0.13; Why = .03) performed better than vitamin D3 (-0.27; 95% CI, -0.27 – 0.41; Why = .69), no significant difference in heterogeneity (I2= 0%, Why = .94).

The researchers also evaluated changes in the Psoriasis Disability Index with 65 patients (23 in the vitamin D group and 42 in the placebo group). They found that the group taking vitamin D treated psoriasis better than the placebo group, but showed no statistical significance.Why = .73).

For changes in the Dermatology Life Quality Index, the team examined 122 patients (60 in the vitamin D group and 62 in the placebo group), finding that the vitamin group treated psoriasis better than the placebo group, but then However, the effect of vitamin D supplementation on dermatological quality of life index was not significant (Why = .11).

As far as changes in C-reaction protein are concerned, researchers examined 45 patients (23 in the vitamin group and 22 in the placebo group), and found no significant findings. Despite the results being insignificant, the vitamin group was better than the placebo group at 3 months and 6 months.

“Although the overall statistical analysis of subgroups for PASI (change at the end of follow-up) values ​​did not show significant evidence of effectiveness, subgroup analysis suggests that supplementing with vitamin D2 may be better than vitamin D3 and more effective. Maybe Asian populations compared to European populations,” the researchers wrote. “The differences between different types of vitamin D and overall may need to be analyzed from a historical perspective.”

When examining the safety of vitamin D supplements for people with psoriasis, adverse events were observed in only 2 of 5 studies. In one study, 2 patients in the vitamin D supplement group and 1 in the placebo group experienced nausea at 3-month follow-up.

Furthermore, a sensitivity analysis, comparing changes in psoriasis area and severity at 3 months, 6 months, and follow-up, demonstrated that the values ​​of change at 3 and 6 months are not “constant”, although at the end of follow-up Was “strong”.

Investigators said the dosage may have been a factor why they were unable to reach any firm conclusions. The Institute of Medicine and Endocrinology recommends a daily dose of vitamin D supplementation of 4000 – 10,000 IU/day. Except that the minimum supplementation is 23857 IU/day and the maximum is 4285 IU/day. Other studies found that taking vitamin D supplements up to 10,000 IU/day was not associated with adverse events. One study found that a dose of 200,000 IU followed by 100,000 IU/month of vitamin D3 produced a significant effect – increasing 23(OH)D levels from 24.8 ng/mL to 41/mL, although Ineffective results were seen. On the other hand, another study showed that 60,000 IU vitamin D2 every 2 weeks improved psoriasis area and severity index scores, yet 25(OH)D levels only increased from 24.77 ng/mL to 27.39 ng/mL. ML is done.

The researchers concluded, “This puzzling situation suggests that the variability in the dosages of vitamin D supplements that have significant utility is so great that it is almost impossible to draw definitive conclusions.” “Therefore, although data from established studies do not suggest that safety is in question, based on the fact that dosage still has to be investigated and the well-known close relationship between it and safety, we believe that vitamin The safety of D supplementation in the treatment of psoriasis remains unclear.”

^Reference

1. ^{Dai Q, Zhang Y, Liu Q, Zhang C. Efficacy and safety of vitamin D supplementation on psoriasis: a systematic review and meta-analysis. one more, 2023;18(11):e0294239. Published 2023 November 15. doi:10.1371/journal.pone.0294239}
2. ^{Psoriasis and Vitamin D deficiency. Harvard Health Publications. 1 August 2012. https://www.health.harvard.edu/diseases-and-conditions/psoriasis-and-vitamin-d-deficiency. Accessed November 21, 2023.}