It demonstrated that the higher the levels of vitamin D in volunteers' blood, the better their gum health. Among men and women aged 50 and older, those with the lowest vitamin D levels had 25 to 27 per cent more tooth loss than had those in the highest range.
The findings are important because both gum disease and vitamin D deficiency are widespread.
Globally, the initial stages of periodontal diseases among adults are prevalent, according to the World Health Organisation. Severe periodontitis is found in 5-15 per cent of most populations, it reports, with smoking, a major risk factor, responsible for more than half of the periodontitis cases among adults.
The chronic inflammatory condition is marked by a loss of attachment of the thin ligaments that connect teeth with their surrounding bone sockets.
Researchers led by Bess Dawson-Hughes, director of the Bone Metabolism Laboratory at the Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts University in Boston studied data on 11,202 men and women aged 20 or older who participated in the third National Health and Nutrition Examination Survey.
The scientists divided the population into five different groups depending on their blood levels of 25-hydroxy vitamin D3, a biomarker indicating vitamin D levels accumulated from both dietary intake and exposure to sunlight.
Four out of the five groups -80 per cent of those studied - had lower-than-desired vitamin D levels, write the researchers in the July issue of the American Journal of Clinical Nutrition (80:108-13). And the lower their vitamin D serum levels, the greater the risk of tooth loss.
Only two previous studies have suggested a link between the vitamin and gum disease, although gum disease was not a primary outcome in the first and the second also included calcium intake.
Scientists believe that vitamin D could affect gum health through its role on bone mineral density but the new trial found no association between bone mineral density and attachment loss or gum disease.
Dawson-Hughes' team believe that the vitamin may however reduce the inflammatory response that leads to periodontal disease. Vitamin D has also been associated with auto-immune diseases such as diabetes, as well as prevention of cancer and fractures.
The new findings were not however seen in younger participants. The researchers could not explain this trend, although they said older people were more susceptible to a benefit from the vitamin given the higher prevalence of tooth loss among the elderly.
"Given the high prevalence of perdiodontal disease and vitamin D deficiency, these findings may have important public health implications," concluded the researchers.
An adequate intake for dietary vitamin D has been established as a range from 200 to 600 international units (IU) daily, depending upon age group, although recent evidence suggests that more vitamin D may be needed.