The Association Between Serum Alpha-Carotene and Root Caries in U.S. Adults: A Cross-Sectional Study

Root caries is a form of decay affecting root surfaces of teeth, often exacerbated by periodontal disease, reduced salivary flow, and compromised mucosal health, all factors strongly influenced by nutrition. Despite this connection, few studies have addressed the role of vitamins in oral health. This study examines the association between serum levels of alpha-carotene (α-carotene), a potent antioxidant and proxy for vitamin A, and the experience of root caries. Using data from the 2017–2018 National Health and Nutrition Examination Survey (NHANES), we conducted a cross-sectional analysis and applied a weighted multiple logistic regression model, adjusting for potential confounders including age, sex, education level, race, income-to-poverty ratio, and presence of gum disease. Higher serum α-carotene levels were inversely associated with root caries. Each unit increase in serum α-carotene was associated with a 9% decrease in the odds of having root caries (OR = 0.91; 95% CI: 0.86–0.97; p = 0.004). In this nationally representative sample of U.S. adults, lower serum α-carotene levels were associated with a higher prevalence of root caries. These findings highlight the potential role of nutritional assessment and integration in oral health. Longitudinal and mechanistic studies are needed to confirm and further explore α-carotene’s effects on oral health.