Combined deficiencies of 25-hydroxyvitamin D and anemia in preschool children with severe early childhood caries: A case-control study.

Background: Severe early childhood caries (S-ECC) is common and has adverse affects on children's health. Children with S-ECC have been shown to have anemia or vitamin D deficiency. No studies have assessed the presence of combined deficiencies with S-ECC. The purpose of our study was to examine whether those with S-ECC had a higher prevalence of combined anemia and low 25-hydroxyvitamin D (25(OH)D) compared to controls. Covariates associated with elevated parathyroid hormone (PTH), previously noted in S-ECC, were examined.

Methods: This is a re-analyses of a previously described cross-sectional case-control study; data were collected between 2009 and 2011. Children with S-ECC were recruited on the day of dental surgery and controls from the community. Blood was drawn for complete blood count, ferritin, 25(OH)D and PTH. Families completed a questionnaire.

Results: A total of 266 children participated (S-ECC n=144); the mean age was 40.8 ± 14.1 months. Children with S-ECC were more likely to have low 25(OH)D, hemoglobin, elevated PTH or iron-deficiency anemia compared to controls. Significant differences between groups were seen for a combined deficiency of low hemoglobin (<110 g/L) and 25(OH)D < 50 nmol/L; controls 0/114 versus S-ECC 15/140 (P<0.001). In an adjusted regression model, PTH was negatively associated with 25(OH)D (P<0.001) and higher income (P<0.02); it was positively associated with less regular milk consumption (P=0.001).

Conclusions: Combined deficiencies of vitamin D and anemia are more prevalent in children with S-ECC; the etiology remains unclear. A detailed diet history is key in those with S-ECC to assess risks for deficiencies.