Association between dietary vitamins intake and the DMFT index: a cross-sectional analysis of the Rafsanjan cohort study

This study aimed to investigate the associations between dietary intake of vitamins and the DMFT index (Decayed, Missing, and Filled Teeth). This cross-sectional study utilized baseline data collected from the Oral Health Branch of the Rafsanjan Cohort Study (OHBRCS). OHBRCS is a part of Rafsanjan Cohort Study (RCS) that begun from 2015 in Rafsanjan in the southeast of Iran. The baseline phase of RCS ended in 2017. The RCS enrolled 9,991 individuals aged 35-70 years from both genders. A comprehensive full-mouth examination was performed to determine the DMFT index. Dietary intakes of vitamins A, E, K, D, C, and B-complex (thiamin, riboflavin, niacin, pyridoxine [B6], folate, cobalamin [B12], pantothenic acid, and choline) were assessed using a validated food frequency questionnaire. Univariable and multivariable linear regression analyses were employed to evaluate the association between vitamin intake and the DMFT index, adjusting for potential confounders. Among 3040 included individuals, the adjusted model showed that the dietary intake > median of Vitamin A (Unstd. B = -0.65 (-1.26, -0.03), p = 0.04), β_carotene (Unstd. B = -0.82 (-1.44, -0.20), p = 0.009), Vitamin K (Unstd. B = -0.72 (-1.33, -0.11), p = 0.02), and thiamin (Unstd. B = -0.84 (-1.47, -0.22), p = 0.008) compared with dietary intake ≤ median, were inversely associated with the DMFT index among males (p < 0.05). Furthermore, the dietary intake > median of lutein_zeaxanthin was inversely associated with the DMFT index, among females (Unstd. B = -0.92 (-1.71, -0.14), p = 0.021). Higher dietary intake of Vitamin A, β_carotene, Vitamin K and thiamin among males and lutein_zeaxanthin among females was associated with lower DMFT scores. However, due to the cross-sectional design, causality cannot be inferred, highlighting the need for future longitudinal studies.