Serum Vitamin D Levels at Birth Are Not Associated With the Formation of Interglobular Dentin in Deciduous Teeth of Modern New Zealand Children.

Interglobular dentin (IGD) has been used as a biomarker for vitamin D deficiency (VDD) in past populations. However, an evidence-based threshold for the levels of serum vitamin D associated with IGD occurrence has not been established. Here, we explore the association between perinatal serum vitamin D levels, presence of IGD, and biological sex in the deciduous teeth of modern children from Otago, New Zealand. Ground sections were created from the deciduous central or lateral mandibular incisors of 54 five to 6-year-old children (27 M, 27 F) with known perinatal blood vitamin D levels. Vitamin D levels at birth were classified as deficient (≤ 30 nmol/L), insufficient (> 30mn/L-< 50 nmol/L), or sufficient (≥ 50 nmol/L), and scanned slides were scored blind by two observers for IGD presence or absence. Thirty-seven individuals (68.5%) exhibited IGD. The distribution of IGD was similar across vitamin D levels considered deficient (35.1%), insufficient (32.4%), and sufficient (32.4%), with no significant association between IGD presence and vitamin D status (p = 0.97) or IGD presence and sex (p = 0.77). Our findings do not support an association between IGD formation in deciduous teeth and vitamin D levels at birth. The prevalence of IGD across the sample, particularly in secondary dentin, suggests IGD may represent a normal developmental feature. However, it is important to note that cord blood vitamin D levels do not reflect the individual's vitamin D status during the entire period of deciduous incisor formation. Further longitudinal clinical research is required to better understand the relationship between VDD and the formation of IGD.