Vitamin D and its analogs have a well-established role in the management of psoriasis, particularly in topical formulations. Psoriasis is a chronic autoimmune skin disease characterized by hyperproliferation of keratinocytes and inflammation. Vitamin D, particularly in the form of vitamin D3 (cholecalciferol) and its synthetic analogs (e.g., calcipotriol), acts by binding to vitamin D receptors (VDR) in the skin, modulating cell growth, differentiation, and immune responses. Multiple randomized controlled trials and meta-analyses have demonstrated the efficacy of topical vitamin D analogs in reducing the severity of psoriatic lesions, especially when used alone or in combination with corticosteroids. The anti-proliferative and immunomodulatory effects help normalize skin cell turnover and reduce inflammation.

Oral vitamin D supplementation has also been explored, with some evidence suggesting that patients with psoriasis may have lower serum vitamin D levels. However, the data supporting oral vitamin D supplementation for psoriasis are less robust compared to topical therapy, with mixed results in clinical trials. Nonetheless, topical vitamin D analogs are widely recommended in clinical guidelines as a first-line or adjunctive therapy for mild to moderate plaque psoriasis. Therefore, the use of vitamin D (especially topical forms) for psoriasis is supported by scientific evidence, though the degree of benefit from systemic supplementation remains less clear.