Exploring the Cardiovascular Impacts of Oral Nicotinamide: A Comprehensive Narrative Review

Nicotinamide (niacinamide) is the water-soluble form of vitamin B3. Nicotinamide plays a crucial physiological role as a catalyst for various molecular reactions in the body and is a common over-the-counter supplement. In dermatology, oral nicotinamide has a long history of diverse applications. Oral nicotinamide mitigates ultraviolet-induced immunosuppression, serves as adjunctive therapy for blistering skin disorders, reduces inflammation and sebum in acne vulgaris, and has been used for pruritic disorders. Recent studies indicate that terminal metabolites of nicotinamide may contribute to vascular inflammation and elevate the risk of cardiovascular disease, particularly at doses exceeding therapeutic recommendations of 500 mg. Given the wide range of applications of nicotinamide in dermatology, we aim to investigate the effects of oral nicotinamide on cardiovascular health.

A review of the literature was conducted to assess the dermatological benefits of oral nicotinamide as well as its potential cardiovascular risks, particularly at high doses. Evidence from clinical trials and meta-analyses was evaluated to synthesize current knowledge on its safety and efficacy.

Oral nicotinamide has demonstrated significant benefits in dermatological practice, including reducing the incidence of non-melanoma skin cancers in immunocompetent individuals and improving outcomes in various inflammatory skin conditions. However, recent evidence suggests that increased serum levels of nicotinamide's terminal metabolites N1-methyl-2-pyridone-5-carboxamide and N1-methyl-4-pyridone-3-carboxamide leads to increased risk of major adverse cardiovascular effects.

While oral nicotinamide remains a valuable option in dermatological practice, clinicians should exercise caution in prescribing this at high doses due to the potential cardiovascular risks.