Vitamin D has been extensively studied in recent years because it seems to have an effect on nearly every body system. A new clinical study review finds that parents may be able to prevent tooth decay by ensuring their children get enough of the “sunshine” vitamin every day.
Vitamin D is already known for strengthening bones and teeth as they mineralize and grow. Unfortunately, the vitamin is naturally present in only a few foods, but it is added to foods that are “fortified,” such as dairy milk and breakfast cereals. Thankfully, our bodies make sure we get the vitamin in other ways besides food. Skin exposure to ultraviolet rays from sunlight can trigger vitamin D synthesis.
But, in today’s modern era, we have found that many people are deficient in vitamin D for a variety of reasons. One, although very important for protection against skin cancer, sunscreen use decreases the amount of UV rays that penetrate the skin in order to start the process of synthesizing vitamin D. Two, we are simply out in the sun less often these days because of work, school, and inactivity (sitting on the couch watching TV instead of going outside to play or walk.) Three, Americans seem to be eating less and less of the foods that contain vitamin D, especially milk. And four, it appears that certain conditions, including obesity, make it more difficult for the body to produce adequate amounts of the vitamin.
The American Medical Association and the US National Research Council first said in 1950 that vitamin D was important for protecting teeth from decay. However, there was not enough evidence at the time to make a conclusive statement. Dr. Philippe Hujoel of the University of Washington decided it was time to “take a fresh look” at the link between Vitamin D and the prevention of dental caries.
Dr. Hujoel and colleagues analyzed 24 clinical trials conducted between 1920 and 1980 which included information on approximately 3000 children between the ages of 2 and 16 from several different countries, including the US, Great Britain, Canada, Austria, New Zealand and Sweden. Most of the studies involved the children being given a vitamin D rich supplement, such as cod liver oil, or estimated their exposure to sunlight.
These trials showed that vitamin D was associated with an approximately 50 percent reduction in the incidence of tooth decay.
Of course, with any study, there were limitations to take into account. "One has to be careful with the interpretation of this systematic review. The trials had weaknesses which could have biased the result, and most of the trial participants lived in an era that differs profoundly from today's environment," Hujoel added.
However, said Hujoel, "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," said Hujoel.
The Recommended Dietary Allowance (RDA) for vitamin D for each age group are as follows:
• Age 0 to 12 months: 400 IU
• Age 1 to 70 years: 600 IU
• Age >70: 800 IU
The best natural sources of vitamin D are fatty fish such as salmon, tuna, swordfish, and mackerel. Dairy foods such as milk and yogurt are often fortified with the vitamin, as are most dairy alternatives such as soy milk. Infant formulas are mandated by law to contain vitamin D – 40 to 100 IU per 100 calories of formula.
As for sunlight, researchers suggest that adults and children get 5 to 30 minutes of sunlight exposure to the face, arms, legs or back between 10 am and 3pm (without sunscreen) at least twice per week.
Philippe P. Hujoel. Vitamin D and dental caries in controlled clinical trials: systematic review and meta-analysis. Article first published online: 9 NOV 2012 in Nutrition Reviews. DOI: 10.1111/j.1753-4887.2012.00544.x
National Institutes of Health, Office of Dietary Supplements