Association between low potassium intake and the number of teeth in Korean adults: based on the national data (2013–2015)

General health and oral health are very closely related. This study aimed to analyze the nutritional factors associated with the number of present teeth in Korean elderly adults. A total of 6,356 individuals were surveyed from the sixth Korean National Health and Nutrition Examination Survey conducted from 2013–2015. The number of existing teeth was divided into three categories: 0–10, 11–20, and over 21, and the nutrition survey covers eating habits, food frequency and food intake using face-to-face interviews. Multiple logistic regression analysis was performed to evaluate the association between nutrient intake and the number of existing teeth after adjusting for socio-demographic factors and general and oral health behaviors and status. As age increases, the number of teeth decreases. Individuals with more teeth had a significantly higher mean daily intake of protein, calcium, phosphorus, potassium and riboflavin (p < 0.05). After adjusting for sociodemographic factors in model 1 and the lower number of teeth in model 2, the strength of the association between the number of teeth and daily calcium intake remained significant. Statistically significant associations were present for dietary potassium intake in models 1 and 2 and in the 11–20 teeth group in model 3 (p < 0.05). We demonstrated a significant association between calcium and potassium intake and the number of teeth.