Vitiligo vulgaris is a common skin disease, however some cases show poor clinical responses to topical steroid ointment or PUVA therapy. Such regimens are generally avoided in the treatment of facial lesions or in pediatric cases because of the undesirable side effects. To confirm the excellent response to combination therapy with topical vitamin D3 ointment and solar irradiation for vitiligo achieved in the initial patients, we conducted an open trial on other patients, most of whom had poor clinical responses to the prior therapies. Fifteen patients (9 men and 6 women) with vitiligo vulgaris were enrolled in this study. Each patient was instructed to sunbathe for 30 minutes within 1 hour after topical application of the tacalcitol [1 alpha 24(OH)(2)D(3)] ointment or cream to the skin lesions every day. Six of 15 patients showed a fair and excellent clinical response to the combination therapy (more than 30% clearance of the vitiligo). The clinical effect was more apparent in patients with a history of less than 5 years of vitiligo (4 of 6 cases) in contrast to those with a history of more than 5 years (2 of 9 cases). In vitro experiments revealed that tacalcitol upregulated the expression of c-Kit mRNA by melanocytes irradiated with linear polarized infrared, UVA or short period solar irradiation. These results suggest that combination therapy with topical vitamin D(3) ointment and solar irradiation can be used as an alternate therapy for vitiligo vulgaris.