Vitamin D status and dental caries in healthy Swedish children

Abstract

Background: 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.

Method: 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 D<subscript>3</subscript> 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.

Results: 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.

Conclusion: 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.

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

Keywords: Vitamin D − Children − caries − enamel defects − LL37.

Conflict of interest statement

Competing interest

The authors declare that they have no competing interests.

Ethics approval and consent to participate

Approval of the study was given by the Regional Ethical Review Board in Umeå, Sweden (References 2012–158-31 M and 2014–103-32 M). Prior to inclusion, each subject got a full written and oral explanation of the purpose and procedure of the study and written informed consent was obtained from the caregivers of the children.

Consent for publication

Not applicable.

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Figures

Fig. 1

Flow diagram of the numbers of children in the basic intervention DViSUM and placebo groups at baseline, 3 month follow up and at the dental follow up at 8 years of age

Fig. 2

PLS correlation coefficients from multivariate modelling with caries status (yes/no) as dependent variables. Correlation coefficients with 95% CI for the variables in the final mode are presented. Bars for which the 95% whisker do not pass zero are statistically significant