Vitamin B3, specifically in the form of nicotinamide (also called niacinamide), has some scientific evidence supporting its use in the management of psoriasis, though the evidence is limited and not yet robust. Psoriasis is a chronic inflammatory skin condition characterized by hyperproliferation of keratinocytes and immune dysregulation. Nicotinamide is known for its anti-inflammatory properties, its ability to modulate immune function, and its role in enhancing the skin barrier by promoting ceramide synthesis.

Several small clinical trials and case reports have suggested that nicotinamide, used either topically or orally, may help reduce the severity of psoriatic lesions. For example, topical preparations of nicotinamide have shown some benefit in improving erythema and scaling in mild to moderate cases, likely due to its inhibition of poly(ADP-ribose) polymerase-1 (PARP-1) and its ability to suppress inflammatory cytokines such as IL-1β and TNF-α. However, these studies are generally small, not always placebo-controlled, and results are sometimes inconsistent.

Major dermatology guidelines do not currently list nicotinamide as a first-line or widely accepted treatment for psoriasis, and more rigorous clinical trials are needed to establish efficacy and optimal dosing. Nevertheless, its favorable safety profile and potential anti-inflammatory effects make it a candidate for adjunctive therapy in some cases. In summary, there is scientific rationale and limited clinical evidence for the use of nicotinamide in psoriasis, but its use is not yet considered standard of care.