Vitamin D insufficiency 'common' among people with psoriatic arthritis
Published on 11 July 2011
A significant proportion of people with psoriatic arthritis have insufficient levels of vitamin D, new research shows.
Scientists at the University of Toronto studied 302 patients with psoriatic arthritis between March and August 2009, some of whom lived in Canada and others in Israel.
Approximately half of the participants were evaluated during the winter, while the other half were assessed during the summer months.
The researchers found that 56 per cent of psoriatic arthritis patients in Canada had insufficient levels of vitamin D in the winter, along with 59 per cent during the summer.
In Israel, 51 per cent of patients had insufficient levels in the winter and 62 per cent in the summer, despite the nation's subtropical southern location.
Overall, there was no significant difference in vitamin D levels between the two locations or the two seasons.
However, the researchers, whose findings are published in the journal Arthritis Care & Research, found no link between a patient's vitamin D levels and their disease activity.
Lead study author Dr Dafna Gladman, director of the University of Toronto's Psoriatic Arthritis Clinic, described vitamin D deficiency as a "widespread concern".
She added: "Additional research is needed to determine if psoriatic arthritis patients require a greater vitamin D intake to maintain healthy levels than that recommended for the general population."
The study is not the first to report reduced levels of vitamin D among patients with autoimmune diseases, as previous studies have found deficiencies in people with diseases such as rheumatoid arthritis, systemic lupus erythematosus and scleroderma.
A spokesman for Arthritis Research UK said the new research confirmed earlier studies which showed that vitamin D deficiency was common in a range of forms of both inflammatory and degenerative types of arthritis, and also in osteoporosis.