Several authors have established a relationship between osteoporosis and periodontal disease. The ageing process is associated with a loss of both oral and total bone mass. It has been shown that a reduction of bone mineralization aggravates pathological periodontal changes, resulting in less support for the teeth. The present study investigates the nutritional influences that may condition the appearance of both pathological process. Insufficient dietary calcium and a reduction in the calcium: phosphorous ratio may favour the appearance of both these conditions by promoting bone reabsorption. Bone loss affects the following in descending order: jaw bones (especially alveolar bone), cranial bones, ribs, vertebrae and long bones. Alveolar bone which has the highest rate of renewal, is affected first and consequently is the most severely affected in the long term. The role of calcium in the etiology of osteoporosis is a controversial issue. Nevertheless, its implication has been proven in numerous investigations. The effect of adequate calcium intake on dental health has formed the basis of several recent studies. These investigations have demonstrated that increased calcium intake improves the suffering of inflammatory processes and tooth mobility in patients suffering from gingivitis with haemorrhaging. Based on the results of studies which link dietary calcium and phosphorous to the risk of osteoporosis and periodontal disease, and bearing in mind that in a large proportion of the Spanish population calcium intake is below that recommended, there is a need for a general improvement of the diet. It may be of special interest to increase the calcium intake of patients suffering periodontal disease. It may also help in the prevention of osteoporosis.