Objectives To determine the level of calcium and vitamin D oral supplementation in patients in periodontal disease maintenance programmes.Design Convenience survey.Setting St. Louis Metropolitan region.Subjects and methods Patients (n = 228) in two university-based, periodontal disease maintenance programmes.Main outcome measures Reported amounts of oral calcium and vitamin D supplementation were tested for differences based on gender and race.Results The last published recommended daily intakes from the United States (US) Food and Nutrition Board (FNB) for adults >50 years of age are 1,200 mg calcium and 400 IU vitamin D (or 600 IU if over 70). The mean age of the 228 patients (125 females and 103 males) was 63.6 ±11.0 years (standard deviation). Of the 228 patients surveyed: (1) 204 (89%) were >50 years of age and of these, only 15 (7%) met the US FNB's recommended intakes of calcium and vitamin D from supplementation; (2) 138 (66%) reported that they took no oral suplementation, with significantly more males (n = 82) than females (n = 56) not taking supplementation (p = 0.03); (3) 88 (39%) took calcium supplementation, with females (947 ± 511 mg/day) taking significantly (p <0.001) more than males (632 ± 907 mg/day); and (4) 66 (29%) took vitamin D supplementation, with females(420 ± 227 IU/day) taking approximately the same amount as males (443 ± 317 IU/day, p > 0.05). The amounts of oral supplementation did not vary with race (p > 0.05).Conclusion The use of calcium and vitamin D supplementation has been promoted for years, yet the numbers of adults taking supplements remains low and the level of supplementation varies greatly. Knowledge of the benefits of supplementation needs to be better disseminated and research needs to be conducted to determine optimal levels of calcium and vitamin D supplementation.