Mechanisms of Calcium Absorption and Factors Affecting Bioavailability: A Review

Osteoporosis negatively affects the quality of life of people 65 years, and it is associated with an increased risk of fracture. It can also lead to decreased mobility and chronic pain. The purpose of this review was to examine the mechanisms of intestinal calcium absorption and the factors limiting calcium bioavailability, and to propose strategies to overcome these limitations while enhancing the efficiency of calcium absorption. Calcium contributes to bone formation and decreases the risk of osteoporosis, and it is absorbed through paracellular and transcellular pathways. However, decreased gastric acid secretion with aging and the presence of intestinal anti-nutrients can decrease the bioavailability of calcium. Thus, the intake of chelated calcium, prebiotic-enriched foods, and supplementation with vitamin D can be effective approaches to enhance the bioavailability of calcium.