Vitamin D supplementation of little help in reducing psoriasis severity
05 Apr 2023
Among individuals with psoriasis, oral vitamin D supplementation does not appear to have any favourable effect on disease severity for those with low 25-hydroxyvitamin D (25[OH]D) levels, as reported in a study.
The study included adults from the general population in Tromsø, Norway, with active plaque psoriasis and 25[OH]D levels <24 ng/mL. They were randomly assigned to receive supplementation with vitamin D (cholecalciferol 100,000 IU loading dose, followed by 20,000 IU per week) or placebo for 4 months.
The primary endpoint was Psoriasis Area Severity Index (PASI), while secondary endpoints included Physician Global Assessment, self-administered PASI, and Dermatology Life Quality Index scores.
A total of 122 individuals with psoriasis (mean age 53.6 years, 37.7 percent women, mean PASI score 3.1, mean serum 25(OH)D 14.9 ng/mL) were included in the analysis, among whom 60 (49.2 percent) were in the vitamin D group and 62 (50.8 percent) were in the placebo group. Fifty-nine participants in the vitamin D group and 61 in the placebo group completed the study.
At study completion, mean 25(OH)D levels were higher in the vitamin D group than in the placebo group (29.7 and 12.0 ng/mL). Changes in PASI score were similar in the two treatment groups (adjusted difference, 0.11, 95 percent confidence interval [CI], −0.23 to 0.45).
Likewise, there were no significant between-group differences observed in the changes in Physician Global Assessment score (adjusted odds ratio, 0.66, 95 percent CI, 0.27–1.63), self-administered PASI (adjusted difference, −0.60, 95 percent CI, −1.76 to 0.55), and Dermatology Life Quality Index (adjusted difference, −0.86, 95 percent CI, −1.9 to 0.19).
No adverse events related to the intervention were recorded.
The null findings may have been affected by the less-than-expected degree of increase in the levels of 25(OH)D in the intervention group (based on previous experimental data from the same source population), according to the researchers.