The effect of the non-calciotropic vitamin D3 analogue MC 903 on psoriasis vulgaris was assessed in a double-blind, placebo controlled trial in 30 patients. Lesions on one side of the body were treated for 6 weeks with a cream containing 10 μ/g, 33 μg//g or 100 μg/g MC 903 and lesions on the other s...