Abstract
Vitamin D is important for calcium and phosphate absorption. Deficiency during pregnancy, as measured by 25-hydroxyvitamin D (25(OH)D), is common in New Zealand, with women living in the South Island having significantly lower mean serum 25(OH)D than those living in the North Island. A postnatal drop in calcium and phosphate signals synthesis of 25(OH)D reserves at birth, enhancing mineralisation potential. Lower maternal levels are associated with lower newborn levels, thereby increasing the risk of mineralisation complications in early life. Teeth are developing during pregnancy and infancy, and enamel defects and caries have been associated with severe 25(OH)D deficiency at this time. The impacts of milder Vitamin D deficiency, however, are still unclear. This study investigated the dental consequences of vitamin D deficiency and insufficiency, as measured by infant 25(OH)D, at birth.
Children from a 2012 vitamin D study (n = 126) were invited to participate. Background data were collected, and dental assessments identified caries risk factors, dental caries and developmental enamel defects. Participants were invited to donate an exfoliated primary incisor. Teeth were cleaned, micro-CT scanned, embedded in epoxy resin and sectioned. One half was subject to Energy Dispersive X-Ray analysis (EDX) and the other half to Raman spectroscopy analyses, which uses photons as a tool to explore molecular vibrations and identify compositional differences in the organic and inorganic structure of a sample.
Eighty-one children participated and 63 teeth were collected. The mean age was 6.6 years, 52% were male, and 80% resided in areas of low or medium socio-economic deprivation (NZDep2018). Two-thirds had an enamel defect present, and half had experienced dental caries. There were no statistically significant differences between 25(OH)D categories and caries risk status, as measured by diet and oral hygiene. Early life 25(OH)D insufficiency was not associated with enamel defect prevalence but was associated with a greater caries risk IRR of 3.55 (CI 1.15-10.92) by age six. No differences in mineral or protein content by 25(OH)D status were identified. Raman spectroscopy data revealed structural differences in enamel quality, with higher enamel crystallinity in participants with sufficient levels of 25(OH)D at birth.
Vitamin D insufficiency during early life may be associated with increased caries risk for children; however, there was no clear association with developmental enamel defects. Vitamin D sufficiency at birth was associated with better enamel crystallinity of developing teeth.