A recent systematic review provides new evidence that Vitamin D is a ‘promising caries-preventive agent’ and that Vitamin D may reduce the incidence of tooth decay (1).

 Tooth decay is a growing concern, particularly among children. A recent study conducted in the UK by toothpaste manufacturer Aquafresh found that almost half of children under the age of 12 have tooth decay. Tooth decay is a preventable disease yet the number of children being admitted for elective extractions of teeth due to caries is increasing yearly.

While the role of Vitamin D in bone health is well known, the evidence base linking Vitamin D and dental health has been less robust until now. 

Teeth are made up of similar tissues to that of bone. It makes sense that a vitamin that is so important in bone health will also play a crucial role in the health of teeth.

Calcium is constantly moving around the body. Teeth, like bones, are mineralised, (i.e. calcium is deposited in teeth), when calcium levels are sufficient. This mineralisation is essential for strong, healthy teeth. When calcium is in short supply it can be leeched from teeth to make up the shortfall, resulting in weaker teeth prone to cavities and decay. Vitamin D is crucial for the proper absorption and utilisation of calcium, and so any deficiency in Vitamin D is likely to affect calcium levels in teeth. 

Vitamin D deficiency has known links to delayed tooth eruption in children, as well as weakened tooth enamel (2). It makes sense that Vitamin D is linked to dental health, and yet until now there has been no comprehensive review of the evidence. "My main goal was to summarize the clinical trial database so that we could take a fresh look at this vitamin D question," said study leader Dr. Philippe Hujoel of the University of Washington.

Dr. Hujoel’s review was published in this month’s issue of Nutrition Reviews. It examined 24 controlled clinical trials, spanning the 1920s to the 1980s. In total, the data covered around 3,000 children and young adults in several countries including the UK. 

Each of the trials used Vitamin D supplemented either through the use of UV light or through dietary supplementation using products such as cod liver oil. 

The review indicated that vitamin D was associated with an approximately 50 percent reduction in the incidence of tooth decay. The study authors noted however that many of the trials had weaknesses that could have affected the results. 

There is currently a huge amount of interest in Vitamin D levels in the general population. Vitamin D levels appear to be falling in many populations, while levels of tooth decay in children are on the increase. "Whether this is more than just a coincidence is open to debate," Hujoel said. "In the meantime, pregnant women or young mothers can do little harm by realizing that vitamin D is essential to their offspring's health. Vitamin D does lead to teeth and bones that are better mineralized." 

References
1. Vitamin D and dental caries in controlled clinical trials: systematic review and meta-analysis. (Nutr Rev. Nov 2012) in  Medical News Today. MediLexicon, Intl., 29 Nov. 2012. Web. 29 Nov. 2012. <http://www.medicalnewstoday.com/releases/253298.php>
2. Misra M et al (2008) Vitamin D Deficiency in Children and Its Management: Review of Current Knowledge and Recommendations. Pediatrics Vol. 122 No. 2 August 1, 2008  pp. 398 -417