How much of calcium from natural sources is absorbed at a time?

The body typically absorbs about 30% to 40% of calcium from natural food sources at a time, though this can vary based on factors such as age, dietary composition, and the presence of other nutrients that enhance or inhibit absorption. For example, vitamin D enhances calcium absorption, while high levels of dietary fiber or certain phytates can reduce it. Additionally, the efficiency of absorption may decrease with higher amounts of calcium consumed in one sitting.