The inorganic part of bone tissue is mainly composed of Ca. In adult people, the resorption processes lead to the removal of minerals from calcified tissues. Women's bodies are particularly vulnerable to a decrease in the concentration of Ca because the osteolysis processes that occur with age are compounded by hormonal changes during the menopause. The aim of the study was to determine the age-dependent concentration of Ca in the bones and teeth of adult women. The object of the research was calcified tissues bones and teeth (n=323). Samples were taken from women aged 26 - 85 years (mean: 55.7 years), living in Poland, in the Silesian Province. Samples were submitted to wet microwave mineralization (spectrally pure nitric acid). The Ca concentration in teeth and bones was determined with the AAS method. The concentration of Ca in the tested samples of calcified tissues from women aged 26 ‑ 85 years was 10.1‑32.0%, and the average concentration was 16.7±3.5% in bones and 22.2±4.7% in teeth. The calcified tissues, from both bones and teeth, show a progressive decrease in the Ca concentration that occurs as women age. The decreasing level of Ca in bone and teeth was statistically significant (p

25.4.2020