Calciumverfügbarkeit

Calciumverfügbarkeit, often translated as calcium bioavailability, refers to the proportion of calcium ingested from food or supplements that is actually absorbed and utilized by the body. Not all calcium consumed is necessarily absorbed. Several factors influence this process, making it a crucial consideration for bone health and overall physiological function.

The primary site for calcium absorption is the small intestine. This absorption occurs through both active and passive transport mechanisms. Vitamin D plays a pivotal role in enhancing the active absorption of calcium, as it promotes the synthesis of calcium-binding proteins in the intestinal cells. Without adequate vitamin D, a significant portion of ingested calcium may not be absorbed.

Other dietary components can also affect calcium bioavailability. Phytates, found in whole grains and legumes, and oxalates, present in spinach and rhubarb, can bind to calcium and form insoluble complexes, thereby reducing its absorption. Conversely, lactose, the sugar in milk, can enhance calcium absorption in some individuals, though this effect is not universal. The overall composition of a meal and individual digestive health also play a part.

The body's physiological state also influences calcium absorption. During periods of rapid growth, pregnancy, and lactation, the body's demand for calcium increases, and absorption rates tend to rise. Conversely, aging can lead to a decline in absorption efficiency. Understanding calcium bioavailability is essential for ensuring adequate calcium intake, particularly for individuals at risk of osteoporosis or calcium deficiency.