To investigate whether gender differences in tooth loss are influenced by caries risk and sources of dietary calcium intake.
This was a cohort study that included 432 Danish adults (30-60 y old) with information on dietary calcium intake in 1982 and 1983 and tooth loss from 1987 and 1988 through 1993 and 1994. Total calcium intake, estimated by a 7-d food record or a a diet history interview, was divided into dairy and non-dairy forms of calcium.
In men, a 10-fold increase in dairy calcium intake was significantly associated with a decreased risk of tooth loss (incidence-rate ratio 0.32, 95% confidence interval 0.15-0.68) even after an adjustment for tooth count in 1987 and 1988, age, education, and civil status (model 1), smoking, alcohol consumption, sucrose intake, and use of vitamin and/or mineral supplements (model 2), time since last dental visit and the presence of oral dryness (model 3), and a high Lactobacillus count (model 4). In women, dairy calcium was not statistically associated with tooth loss in the crude and adjusted models (models 1 to 3). However, the association became highly significant once the Lactobacillus count was included in model 4 (incidence-rate ratio 0.25, 95% confidence interval 0.09-0.73). Non-dairy calcium was not associated with tooth loss in men and women in the fully adjusted models.
Dietary calcium intake, particularly calcium from dairy products, seems to protect against loss of teeth in adult men and women. The previous gender differences found in the relation between calcium intake and tooth loss may be the result of differences in the caries risk between genders.