Calcium is an essential nutrient required for numerous biological functions. Studies have demonstrated an association between low calcium intake and chronic diseases, such as osteoporosis, colon cancer, hypertension, and obesity. However, most Brazilians do not meet the adequate intake for calcium. This review focuses on the endogenous (age, hormonal state) and exogenous (phytate, oxalate, sodium, bioactive compounds and vitamin D) factors that can influence calcium absorption. The main methods used for evaluating calcium absorption and bioavailability. The potential factors for the low calcium intake: 1) Food habits - substitution of milk for soft drinks, eating away from home and skipping meals specially breakfast; 2) High cost of dairy food. Besides, this article discuss strategies to optimize calcium intake: 1) Increase knowledge of the relationship between calcium and health and the main food sources; 2) Increase availability of calcium-fortified foods; 3) Supplement use for target groups - when and how administrate calcium salts.
calcium; absorption; bioavailability; intake; calcium salts