Study sees low 'D' in PsA patients

Toronto - Patients with psoriatic arthritis (PsA) have a high prevalence of vitamin D insufficiency, HealthDay News reports.

However, no evidence of seasonal or geographic variation was found, nor did researchers find any link between vitamin D levels and disease activity, according to the report.

A study headed by Zahi Touma, M.D., of the Toronto Western Hospital, investigated the prevalence of vitamin D deficiency and insufficiency in 302 patients with PsA, its seasonal and geographic variation, and the possible correlation with disease activity. The study was conducted in a northern geographic area and a southern subtropical region from March to August 2009. A total of 258 participants were assessed in winter and 214 in summer, with most assessed in both seasons.

Investigators found that in the winter, serum 25-hydroxyvitamin D (25[OH] vitamin D) levels were insufficient in 55.7 percent of patients in the northern location and 50.9 percent of patients in the southern location. In the summer, levels were insufficient in 58.6 percent of the northern patients and 62.2 percent of the southern. No association was observed between vitamin D levels, race, employment status, skin phototype, seasonal and geographic interaction, or disease activity in summer or winter. There was no association between disease activity in summer and vitamin D levels in winter.

“A high prevalence of vitamin D insufficiency among PsA patients was found,” the authors concluded. “There was no seasonal variation in 25(OH) vitamin D levels among PsA patients in the southern and northern sites. No association could be established between disease activity and vitamin D level.”

The study was published online July 11 in Arthritis Care & Research.