FRIDAY, July 28, 2023 (HealthDay News) -- Lower vitamin D levels and a higher proportion of vitamin D deficiency are associated with increasing psoriasis severity, according to a study presented during NUTRITION 2023, the annual meeting of the American Society for Nutrition, held from July 22 to 25 in Boston.

Rachel K. Lim, from the Warren Alpert Medical School of Brown University in Providence, Rhode Island, and colleagues examined associations between 25-hydroxyvitamin D (25[OH]D) status and psoriasis severity among 40,401 participants (491 psoriasis cases).

The researchers observed a linear trend between increasing severity of psoriasis and decreasing serum 25(OH)D levels. Patients with the least body surface area (BSA) affected by psoriasis showed the highest mean 25(OH)D levels (67 nmol/L), while those with the greatest BSA had the lowest mean 25(OH)D levels (56 nmol/L). Similar results were seen when percentage of vitamin D deficiency was evaluated by BSA, with 25 percent of patients in the lowest BSA category and 39 percent of patients in the highest BSA category being vitamin D-deficient.

"Topical synthetic vitamin D creams are emerging as new therapies for psoriasis, but these usually require a doctor's prescription," Lim said in a statement. "Our results suggest that a vitamin D-rich diet or oral vitamin D supplementation may also provide some benefit to psoriasis patients."