February 4 (HealthDay News) -- Galderma Laboratories' Vectical (calcitriol) ointment has been approved by the U.S. Food and Drug Administration to treat mild-to-moderate plaque psoriasis in adults, the company said.

Approval was based on two eight-week studies involving more than 800 people. Improvement was first observed at week two, Galderma said in a news release.

The most frequently reported side effects included skin discomfort and high amounts of calcium in the urine.

Psoriasis is a chronic skin disorder characterized by thick, dry scaly patches. Up to 3 percent of the U.S. population has the disorder, accounting for millions of hours of lost productivity each year, the company said.