Vitamin D Supplementation During Pregnancy Reduces Enamel Defects in Offspring

By Will Boggs MD

August 10, 2019

NEW YORK (Reuters Health) - High-dose vitamin D supplementation during pregnancy decreases the risk of enamel defects in offspring, according to a post hoc analysis of a randomized controlled trial.

"Vitamin D is essential for mineralization, but previous research has focused on bone mineralization," Dr. Hans Bisgaard of the University of Copenhagen, in Gentofte, Denmark, told Reuters Health by email. "We hypothesized that a similar mechanism may be involved in formation of teeth during pregnancy."

Dr. Bisgaard and colleagues hypothesized that vitamin D deficiency during pregnancy and shortly after birth contributes to enamel defects and/or caries development and that high-dose vitamin D supplementation (2,400 IU/day) during pregnancy may lower those risks.

The team used data from 588 children of mothers participating in the Copenhagen Prospective Studies on Asthma in Childhood 2010 who completed a comprehensive dental examination when their child was 6 years old.

Mean serum vitamin D3 levels increased significantly from 30.77 ng/mL to 43.35 ng/mL in mothers allocated to vitamin D supplementation, but not in mothers in the control group, who received 400 IU/day, in whom levels decreased from 30.61 ng/mL to 28.97 ng/mL.

Enamel defects were diagnosed in the permanent dentition of 70 children (21.1%) and in the deciduous dentition of 61 children (12.3%), the researchers report in JAMA Pediatrics, online August 5.

Compared with that control group, the adjusted odds of having enamel defects were 58% lower in permanent dentition, 46% lower in deciduous dentition and 48% lower in permanent and/or deciduous dentition in the supplementation group, all significant effects.

The prevalence of caries was 23% overall (4.2% in the permanent dentition and 20.2% in the deciduous dentition) and was not associated with enamel defects or with vitamin D supplementation.

"High-dose vitamin D not only reduced enamel defects but also reduced risk of asthma-like symptoms in children," Dr. Bisgaard said. "Therefore, it may be prudent to consider recommendation of a higher dose."

"The multi-organ effect from vitamin D given during pregnancy shows how trajectories to health or disease are laid out during pregnancy," he said. "This fascinates me and should advise us all to consider pregnancy as a fragile period of life."

Dr. Susan G. Reed of the Medical University of South Carolina, in Charleston, who previously described a link between maternal vitamin D concentrations and offspring enamel hypoplasia, told Reuters Health by email, "These results are some of the best evidence to date supporting the need for high-quality dental research contributing to the frontier of knowledge for sound tooth development. Evidence continues to support that 400 IU/d does not meet desired health outcomes."

"Studies specifically designed for dental outcomes are needed to determine the optimal levels of vitamin D and related factors during tooth development," she said.

Dr. Robert J. Schroth from The Manitoba Institute of Child Health, in Winnipeg, Canada, who has researched prenatal vitamin D and dental caries in infants, told Reuters Health by email, "I think this study adds to the growing evidence that good nutrition during pregnancy and early life can have benefits for a child's oral health. The developmental origins of dental problems like enamel defects and caries truly begin prenatally."

"I think vitamin D supplementation during pregnancy is important, but this should be discussed with one's primary-care provider," he said. "Not all women require high-dose supplementation. Those that might benefit would be those living in northern regions of the U.S. and Canada, those with darker skin, those who don't spend time outside in the sun and don't have diets with foods fortified or rich in vitamin D. Anyone contemplating high-dose supplementation should first have their physician determine their 25(OH)D level to see if it needs to be increased beyond 50 nmol/L (20 ng/mL) or 75 nmol/L (30 ng/mL)."

"Physicians, and dentists too, should be aware that prenatal vitamin D intake and supplementation can influence the development of the primary and early permanent dentition," Dr. Schroth said. "Good nutritional status and intake of foods rich in vitamin D and vitamin D supplementation are needed for the development of good bones and teeth."


JAMA Pediatr 2019.