Vitamin D status and dental caries in healthy Swedish children

Vitamin D is crucial for mineralized tissue formation and immunological functions. The purpose of this study was to evaluate the association between vitamin D status and dental status in healthy children with vitamin D supplementation in infancy and at 6 years of age.

Eight-year-old children who had participated in a vitamin D intervention project when they were 6 years old were invited to participate in a dental follow-up study. They had fair or darker skin complexion and represented two geographically distant parts of Sweden. 25-hydroxy vitamin D in serum had been measured at 6 years of age and after a 3-month intervention with 25, 10 or 2 (placebo) μg of vitamin D3 per day. Two years later, caries and enamel defects were scored, self-reported information on e.g., oral behavior, dietary habits and intake of vitamin D supplements was collected, and innate immunity peptide LL37 levels in saliva and cariogenic mutant streptococci in tooth biofilm were analyzed. The outcome variables were caries and tooth enamel defects.

Dental status was evaluated in 85 of the 206 children in the basic intervention study. Low vitamin D levels were found in 28% at baseline compared to 11% after the intervention, and 34% reported continued intake of vitamin D supplements. Logistic regression supported a weak inverse association between vitamin D status at 6 years of age and caries 2 years later (odds ratio 0.96; p = 0.024) with minor attenuation after an adjustment for potential confounders. Multivariate projection regression confirmed that insufficient vitamin D levels correlated with caries and higher vitamin D levels correlated with being caries-free. Vitamin D status at 6 years of age was unrelated to enamel defects but was positively associated with saliva LL37 levels.

An association between vitamin D status and caries was supported, but it was not completely consistent. Vitamin D status at 6 years of age was unrelated to enamel defects but was positively associated with LL37 expression.

The basic intervention study was registered at ClinicalTrials.gov with register number NCT01741324 www.clinicaltrials.gov/ct2/show/NCT02347293 on November 26, 2012.