A causal association between 25-hydroxycholecalciferol (genetically predicted vitamin D) concentrations and psoriasis and systemic lupus erythematosus is supported by genetic evidence, according to a study published in Seminars in Arthritis and Rheumatism. Stephen Burgess, PhD, and colleagues analyzed data from 332,984 participants, of whom 23,089 had at least one autoimmune disease. Population-wide analysis was conducted using the ratio method. They evaluated nonlinear effects across five quantiles based on vitamin D levels. Genetically predicted vitamin D was linked with lower risk for diseases in the autoinflammation group (OR, 0.95 per 10 ng/mL increase in 25-hydroxycholecalciferol; 95% CI, 0.91-0.99; P=0.03) but not the autoimmunity group (OR, 0.99; 95% CI, 0.95-1.03; P=0.64) or combined. For patients with psoriasis, genetically predicted vitamin D was linked with lower risk (OR, 0.91; 95% CI, 0.85-0.97; P=0.005), the most common disease in the autoinflammation group. “These results have implications for potential disease prevention strategies and the interpretation and design of vitamin D supplementation trials,” the study authors wrote.
