Lower prenatal vitamin D increases risk of cavities in infants

By Will Boggs MD

Lower prenatal vitamin D levels in mothers were associated with an increased risk of dental caries in infants in a recent prospective cohort study from Canada.

Vitamin D deficiency in utero is believed to be associated with enamel hypoplasia and thereby to increase the risk of caries. This may be most important during the second trimester when primary tooth calcification begins, according to Dr. Robert J. Schroth from the University of Manitoba in Winnipeg and colleagues.

The mean maternal prenatal 25-hydroxyvitamin D (25OHD) level - as derived from the 207 women who originally enrolled in the study -- was 48 nmol/L. About a third of participants(65/207, 32.5%) were deficient (defined here as <35 nmol/L), and 24 women (12%) had optimal levels (i.e., at least 75 nmol/L).

In the 135 babies who returned for the infant follow-up visit, the researchers looked for decayed primary teeth as well as incipient and noncavitated caries of enamel (white spot lesions). The mean age was 16 months; the median was 19 months.

The authors saw enamel hypoplasia in 22%. Nearly a quarter (23%) had early childhood caries when the definition was restricted to cavitated enamel lesions. More than a third (36%) had early childhood caries when white spot lesions of enamel were included in the definition.

Mothers of infants with early childhood caries under the more restricted definition had lower prenatal 25OHD concentrations than mothers of caries-free children, but there was no difference between groups when white spot lesions were included.

Using the deficient and optimal cutoffs did not significantly associate 25OHD categories with early childhood caries, but Poisson regression revealed a significant inverse relationship between the average number of decayed teeth and the prenatal 25OHD level.

Enamel hypoplasia, infant age, and lower 25OHD levels were significantly and independently associated with early childhood caries after controlling for income and employment status, infant feeding methods, season, and infant oral hygiene practice.

"Attempts to improve nutrition during tooth formation in utero and early childhood should be examined as a potential strategy to reduce the risk of caries," the authors conclude. "Prevention efforts should begin during pregnancy by bolstering maternal nutrition, either through improved dietary intake or supplementation with vitamin D."

Dr. William B. Grant from Sunlight, Nutrition, and Health Research Center, San Francisco, California is a long-time proponent of vitamin D supplementation. He told Reuters Health, "All pregnant and nursing women need to take 4000-5000 IU/d vitamin D3. There are many benefits for pregnancy outcomes including reduced risk of gestational diabetes, respiratory and other infections, premature delivery, pre-eclampsia, adverse effects on the fetus such as birth defects including very possibly autism."

"There has been a spate of publicity lately regarding vitamin D and the disparities between observational studies related to 25OHD levels and the results of randomized controlled trials (RCTs)," Dr. Grant said. "The reason for the disparities is that most RCTs are performed on the general population with population average 25OHD levels of 20-30 ng/mL. RCTs have been designed on the pharmaceutical drug model: the trial provides the only source of the agent and there is a linear dose-response relation. Neither assumption is correct for vitamin D."

Dr. Philippe P. Hujoel from University of Washington, Seattle, Washington recently reviewed the association of vitamin D and dental caries in controlled clinical trials. He told Reuters Health, "The National Academy of Sciences, the American Medical Association, and the American Dental Association all recommended vitamin D supplementation for dental caries prevention a long time ago. What is surprising is how this common wisdom regarding the role of vitamin D in dental caries prevention became largely forgotten."

He stopped short, though, of endorsing vitamin D supplementation in pregnancy. "The current evidence is insufficient to suggest that the benefits of vitamin D supplementation in pregnancy would outweigh the risks," Dr. Hujoel said. "In place of supplementation, I would recommend maintaining proper vitamin D levels during pregnancy the natural way - enjoy the sun, choose foods such as wild salmon, Ahi tuna, mushrooms, and eggs. Additionally, reducing carbohydrate intake will reduce the body's need for vitamin D."

"The main message for physicians is that teeth are first to suffer in terms of proper development when vitamin D levels are suboptimal," Dr. Hujoel concluded. "And this damage is irreversible."

Dr. Schroth did not respond to a request for comments.

SOURCE: http://bit.ly/1gNCsnP

Pediatrics 2014;133:e1277-e1284.

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