Does vitamin D enhance periodontal health?

Vitamin D supplements can play a positive role in supporting and improving periodontal health in older adults and pregnant women, according to two new studies in the Journal of Periodontology (JOP, September 1, 2010).

In 2009, researchers from Saint Louis University, Southern Illinois University, and Washington University found that patients in periodontal maintenance programs taking vitamin D and calcium supplementation trended toward better periodontal health compared with patients not taking supplementation (JOP, September 2009, Vol. 80:9, pp. 1433-1439).

And this is just one of many cross-sectional studies and secondary data analyses in the last few years that reached similar conclusions, according to Charles Hildebolt, DDS, PhD, study co-author and director of radiology at the Mallinckrodt Institute of Radiology at Washington University.

Vitamin D stimulates the production of natural antibiotics -- antimicrobial peptides -- and bacteria and viruses have a hard time developing a resistance to them, he told DrBicuspid.com.

"Periodontal disease is largely an immune response to bacteria in the biofilm, so if vitamin D stimulates production of natural antibiotics, this might be good in preventing periodontal disease," he said.

Dr. Hildebolt and his colleagues acknowledge, however, that the effects of vitamin D and calcium supplementation on periodontal disease have not been completely clarified in the scientific literature.

"Although a number of early studies suggested that vitamin D and calcium supplementation reduced tooth loss and alveolar ridge resorption, most of these studies included heterogeneous populations or did not directly measure periodontal diseases status," they wrote. More recently, however, analyses of the Third National Health and Nutrition Examination Survey, which included 12,000 adults, revealed significant associations between periodontal health and and calcium intake, they noted (JOP, July 2000, Vol. 71:7, pp. 1057-1066).

Even so, the National Institute of Dental and Craniofacial Research (NIDCR) wants more evidence on the effects of vitamin D on periodontitis before it will fund randomized clinical trials on this topic, according to Dr. Hildebolt. And on November 30, the Institute of Medicine (IOM) released a report that, while increasing the recommended daily intake of vitamin D and calcium, said that the current body of research does not offer the evidence needed to confirm that vitamin D has the larger positive health effects its proponents claim it does.

The IOM's report is a move in the right direction, Dr. Hildbebolt said. But he also believes there is enough evidence to support research into the effects that higher levels of vitamin D may have on periodontal disease.

"There have been many, many randomized clinical trials that have shown the benefits of vitamin D and calcium in preventing bone loss below the head, and everyone agrees that you need an adequate intake of vitamin D to promote calcium absorption," he told DrBicuspid.com. "So it seems reasonable that bone in the head is not too much different from bone in the rest of the body. If it is beneficial to those bones, it is probably also beneficial to the alveolar bone."

One-year findings

In an effort to convince the NIDCR of this, Dr. Hildebolt and colleagues went back to the same patient group from the 2009 JOP study to see if the trends they had initially found in the relationship between periodontal health and vitamin D and calcium supplements persisted after one year.

Their latest JOP study followed the original 51 patients (men and women age 50-80), who had moderate to severe chronic periodontal disease (at least two interproximal sites with at least 3 mm of clinical attachment loss) and were enrolled in maintenance programs at two dental clinics.

The patients were divided into two groups: 23 had been taking vitamin D (at least 400 international units [IU] per day) and calcium (at least 1,000 mg per day) supplements for more than 18 months at the time of their baseline visits, while the other group (28) had been taking no supplements and had daily dietary intakes of calcium and vitamin D below 1,000 mg and 400 IU, respectively.

All patients were clinically assessed using probing and CEJ-GM (cemento-enamel junction - gingival margin) measurements at baseline, six months, and one year. Clinical measurements were taken at six sites (buccal, lingual, me = 0.049), siolingual, mesiobuccal, distolingual, and distobuccal) for each mandibular posterior tooth. In addition, bitewing radiographs of the mandibular posterior teeth were taken at baseline, six months, and one year.

All subjects from both groups received periodontal maintenance therapy at three-month intervals. Treatment consisted of scaling and root planing, polishing, reinforcement of oral hygiene procedures, and a general dental exam.

For subjects who did not take oral supplements, the mean daily calcium intake was 642 mg and the mean daily vitamin D intake was 156 IU. For subjects who did take oral supplements, the mean daily calcium intake was 1,769 mg and the mean daily vitamin D intake was 1,049 IU.

Clinical parameters of periodontal health improved with time in both groups (p < 0.001). When clinical measures were considered collectively, the differences between supplement takers and nontakers had the following p values: baseline (p = 0.061), six months (p = 0.049), and 12 months (p = 0.114).

"This study suggests that periodontal health improves in patients attending regular periodontal care programs, regardless of their dietary calcium or vitamin D supplements," the authors wrote. "However, taking calcium and vitamin D supplementation is associated with better periodontal health relative to taking no such supplements."

The researchers observed less bleeding on probing and less inflammation in supplement takers, a difference that was evident at baseline and remained significant for one year while subjects underwent periodontal maintenance therapy.

"Our findings do not deny the possibility that vitamin D supplements may reduce the severity of periodontal disease if used at doses higher than 800-1,000 IU daily, thus supporting the rationale for testing the potential beneficial role of vitamin D on periodontal disease in more powerful, randomized clinical trials," they concluded.

Good for pregnant women too

Lack of vitamin D is also associated with maternal periodontal disease during pregnancy, according to researchers from the University of North Carolina at Chapel Hill and Harvard Medical School (JOP, September 1, 2010). In fact, maternal periodontal disease is found in up to 40% of pregnant women and is associated with adverse pregnancy outcomes, including preterm birth, preeclampsia, and late miscarriage, the authors noted.

In their case-control study, 117 cases of pregnant women with moderate to severe periodontal disease (15 or more tooth sites with 4 mm or more of gingival pocket depth) were compared with 118 pregnant women who were periodontally healthy. All the women had been prescribed a prenatal vitamin containing 400 IU of vitamin D.

Their serum 25-hydroxyvitamin D (25[OH]D) levels were measured and compared between the case and control groups to determine the prevalence of vitamin D insufficiency (defined as < 75 nanomoles per liter [nmol/L]). A serum concentration of 75 nmol/L or greater appears to support bone mineral density and dental health, the authors noted, and 90-100 nmol/L has been suggested as the optimal vitamin D level (American Journal of Clinical Nutrition, July 2006, Vol. 84:1, pp. 18-28).

The researchers found that the case group had lower median 25(OH)D levels than the control group (59 versus 100 nmol/L, p < 0.001) and were more likely to have vitamin D insufficiency (65% versus 29%, p < 0.001).

"The relationship between maternal vitamin D status, periodontal disease, and adverse pregnancy outcomes requires more study before definitive conclusions can be made," they wrote. "However, our data provide evidence that improvement of vitamin D status is a potential intervention to improve oral health among a vulnerable group of pregnant women."

Given the role of vitamin D in inflammatory responses and integrity of the innate immune response, vitamin D supplementation could improve maternal oral health, the researchers concluded.

Dr. Hildebolt believes that the best way to determine if patients are getting enough vitamin D from sunshine and diet is to test their blood for serum 25(OH)D levels. If less than 75 nmol/L of serum 25(OH)D is present, then a supplement may be warranted.

"There is a lot of hype about vitamin D right now," Dr. Hildebolt said. "It's not the magic bullet that will cure all forms of cancer, but it is much better to have too much than not enough. And it is very difficult to get too much vitamin D, and to get enough just from diet alone."

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