Vitamin B3, also known as niacin or nicotinamide, has some scientific evidence supporting its use in the management of psoriasis, though the evidence is limited and not robust. Nicotinamide, a form of vitamin B3, has anti-inflammatory properties and has been investigated for its effects on skin barrier function and inflammation, both relevant to psoriasis pathophysiology. A small number of clinical studies and case reports suggest that topical or oral nicotinamide may help reduce inflammation and improve skin lesions in psoriasis, potentially by inhibiting poly(ADP-ribose) polymerase-1 (PARP-1) and reducing keratinocyte proliferation.

However, large-scale, high-quality randomized controlled trials are lacking, and vitamin B3 is not considered a first-line or standard treatment for psoriasis. Most clinical guidelines do not currently recommend its routine use for this condition. The most promising results come from topical formulations in small pilot studies, where some improvement was noted in psoriatic plaques. Oral niacin/niacinamide has been used historically for general skin health, but evidence for its efficacy in psoriasis specifically remains weak.

In summary, while there is some scientific rationale and preliminary evidence for vitamin B3 in psoriasis, it is not yet strongly validated, and more research is needed to establish its role in treatment.