When Diet Trends Go Viral: Cutaneous Manifestations of Social Media-Driven Fad Diets and Supplements.

The rise of fad diets and unregulated supplement use, amplified by social media and aggressive marketing, has dramatically shifted public attitudes toward nutrition and health. This new landscape is associated with a growing spectrum of dermatologic presentations, as the skin frequently serves as an early indicator of both nutritional deficiencies and toxicities. Popular dietary trends, such as ketogenic, carnivore, and raw vegan regimens, have been linked to cutaneous disorders, including prurigo pigmentosa, scurvy-like eruptions, hair loss, xerosis, and pigmentary changes. In parallel, the overuse of supplements like niacin, selenium, and zinc is increasingly implicated in cases of dermatologic toxicity, presenting as flushing, dermatitis, alopecia, and nail dystrophy. Fitness-oriented supplements, particularly whey protein, are now recognized contributors to acne flares, likely via insulin and IGF-1 pathways. Given the high prevalence of health misinformation online and the lack of regulation surrounding dietary supplements, dermatologists and allied clinicians must prioritize thorough dietary and supplement histories, recognize the skin's role as an early warning system for nutritional imbalance, and provide evidence-based patient counseling. A multidisciplinary approach that integrates clinical vigilance, interdisciplinary education, and public health advocacy will be crucial for reducing the burden of nutrition-related skin disease and promoting safe, effective dietary practices. The clinical recognition of these diet- and supplement-induced dermatoses is complicated by their overlap with more common inflammatory or autoimmune skin diseases, often leading to misdiagnosis and delayed management of the underlying nutritional etiology.