Pregnancy and child dental health: new evidence on vitamin D

The results are published in JAMA Network Open.

Early childhood caries is one of the most common childhood health problems. This diagnosis is generally defined as the presence of at least one carious lesion (including initial, "non-carious" enamel defects), tooth extractions or fillings in children under 71 months of age. The disease can lead to pain, chewing problems and complications, and affects a child's appearance and quality of life, increasing the burden on families and the health system.

Estimated global data from 2007-2017, the average prevalence of early dental caries was about 23.8% in children under 3 years old and 57.3% in children 3-6 years old. In China, a 2015 national survey found tooth decay in 71.9 per cent of five-year-old children.

Why vitamin D could be important

Mineralisation of baby teeth starts as early as pregnancy. Vitamin D is involved in the metabolism of calcium and phosphate, which are essential for enamel formation, and also supports remineralisation processes after teeth erupt. According to the authors, vitamin D receptors are present in cells that form enamel and dentin, indicating a potential role for the vitamin in tooth development.

Current recommendations generally focus on maintaining 25-hydroxyvitamin D levels (a key marker of vitamin D status) above 30 ng/ml, but vitamin D deficiency remains common.

How the study was conducted

The authors used data from a cohort of pregnant women from Zhoushan City, Zhejiang Province. They included 4,109 mother-child pairs in the study . Women had their 25-hydroxyvitamin D levels measured in the first, second and third trimesters, and then children had early childhood dental examinations (with follow-up).

At the last dental examination, early childhood caries was detected in 960 children, while 3,149 showed no signs of caries. Vitamin D deficiency was defined in the paper as a level below 20 ng/ml.

What the results showed

Statistical analysis showed: higher 25-hydroxyvitamin D levels during pregnancy generally corresponded to a lower chance of a child developing dental caries. The association was most pronounced for the second and third trimesters - during these periods, vitamin D levels were lower in mothers of children with caries than in mothers of children without caries. According to the authors, the middle and end of pregnancy appears to be the window when the link between vitamin D and the future condition of a child's teeth is stronger.

The researchers note that their findings support the idea: maintaining adequate vitamin D status before conception or during pregnancy may be one of the factors that can reduce the risk and severity of early childhood tooth decay. However, this is an observational study that identifies an association, but does not in itself prove causation or replace clinical advice from a physician.