Are low serum levels of Vitamin D associated with dental developmental defects in primary teeth? A systematic review

To identify, qualify and synthesize all studies that assessed if low serum level of 25(OH)D (<50 nmol/L) is associated with dental developmental defects (DDD) in primary teeth.

Observational studies or clinical trials were included if measured 25(OH)D serum levels in pregnant women and/or in their children (up to 3 years old) and evaluated the occurrence of DDD in the primary dentition of offspring associated with the low 25(OH)D levels. Literature reviews, case reports, laboratory and/or animals' studies, conference abstracts, letters to the editor, book chapters and clinical protocols were excluded. Searches were carried out in 6 electronic databases and in the gray literature until March 2023, without restrictions. The study quality was assessed by the Newcastle-Ottawa Scale and the certainty of the evidence by GRADE. Data were descriptively synthesized considering the association between DDD and 25(OH)D levels.

Seven studies were included. Only developmental enamel defects (DED) were observed after examination of 6651 children. The incidence of DED ranged from 8.9% to 66%. Six studies found no association between low levels of 25(OH)D and DED. However, one reported correlation between hypomineralization of the primary second molar (HSMD) and low levels of 25(OH)D at birth. Methodological flaws were observed in all studies and the certainty of the evidence was very low.

Although HSMD was the only DDD associated with low levels of 25(OH)D in children, the available evidence is still not conclusive. More robust studies are needed to endorse the biological plausibility of DDD in primary teeth due to low serum levels of 25(OH)D in pregnant women or in their children. FAPERJ financed this study, which was registered in PROSPERO (CRD42022357511).