Diet is known to play a role in the development of skin disorders. While a vegan diet is frequently described as a risk factor for skin disease secondary to nutritional deficiency, this risk may be overestimated. The recommended daily amounts of nutrients and vitamins can be fulfilled on a vegan diet. Vegan diets also avoid food groups such as dairy and other animal-based products, which holds benefits in inflammatory skin diseases including acne, psoriasis, hidradenitis suppurativa, and atopic dermatitis. Overall, the risk of skin disease secondary to nutritional deficiency in patients following a vegan diet is very low and likely over-emphasized. A well-balanced and conscientiously planned vegan diet can adequately provide the necessary amounts of proteins, vitamins, and minerals to support skin health.  The role of diet in maintaining skin health cannot be overstated. Both inadequate and excess nutrient consumption may be associated with skin disorders, including acne vulgaris, psoriasis, hidradenitis suppurativa, and atopic dermatitis. Diet is a main contributor to diversity in the gut microbiome. An altered gut microbiome, or gut dysbiosis, is associated with an altered immune response, promoting the development of such skin diseases.
Despite the importance of nutrition in skin health, there is much confusion surrounding the ideal diet for optimal skin health, particularly for those following a vegan diet. A vegan diet, which excludes all animal-derived products including meat, poultry, seafood, eggs, dairy, gelatin, and honey, may increase the risk of certain nutritional deficiencies, some of which are associated with skin disorders. The vegan diet includes the consumption of plant-based foods such as nuts, grains, seeds, legumes and derivatives, fruits, and vegetables. Nevertheless, ensuring a sufficient intake of vitamins and nutrients through a healthy vegan diet and appropriate supplements can prevent nutritional deficiencies. In a recent comprehensive review of nutritional deficiency and skin disease, a vegan diet was listed as a risk factor for riboflavin and vitamin A deficiencies, and a potential risk factor for lower protein intake. A vegan diet was the only diet highlighted as a risk factor for deficiency; thus, other diets were not included as a focus of this review. In addition, nutritional deficiencies associated with veganism that do not cause frequent dermatologic manifestations are outside the scope of this review. For example, vitamin B12 is only present in animal products, and thus, a vegan diet lacks vitamin B12 completely and supplementation is required. Vitamin B12 was not included in this review as the manifestations of deficiency are rarely cutaneous.