Beta-carotene is a precursor to vitamin A, an essential nutrient known for its role in maintaining healthy epithelial tissues, including the mucous membranes of the respiratory, digestive, and genitourinary tracts. Scientific evidence supports that beta-carotene, when consumed in the diet, is converted into retinol (vitamin A) in the body as needed. Vitamin A is crucial for the differentiation and maintenance of epithelial cells, which are foundational to the integrity and function of mucous membranes (NIH Office of Dietary Supplements). Deficiency in vitamin A is well-documented to lead to keratinization and dysfunction of mucous membranes, increasing susceptibility to infections and tissue damage.

Several clinical and observational studies have highlighted the importance of adequate vitamin A status in supporting mucosal immunity and barrier function, particularly in populations at risk of deficiency. While direct supplementation with beta-carotene is effective in populations with low dietary vitamin A, high-dose beta-carotene supplementation is not generally recommended for the general population due to mixed results regarding efficacy and concerns in smokers. Nevertheless, the scientific rationale for its use to support mucous membrane health is strong, as beta-carotene serves as a critical source of vitamin A in plant-based diets and is recognized for this purpose by health authorities.