MRCP UK EXAMINATIONS

Detailed explanation-1: -Calcium is absorbed in the mammalian small intestine by two general mechanisms: a transcellular active transport process, located largely in the duodenum and upper jejunum; and a paracellular, passive process that functions throughout the length of the intestine.

Detailed explanation-2: -The small intestine, which is the part of the digestive system just beyond the stomach, is where calcium is taken by the blood and transported to bone and other tissues. The amount of calcium absorbed is dependent on several key factors: Amount of calcium already in the blood.

Detailed explanation-3: -In the calcium absorptive process the duodenum has been the major focus of research due to its highly active transport system. However, it is the distal intestine where 70-80 % of the ingested calcium is absorbed (mostly in the ileum) (Wasserman 2005).

Detailed explanation-4: -Calcium that reaches the large intestine undergoes absorption there by both active and passive processes. Probably no more than 10% of total calcium absorption takes place in the large intestine, whether calcium intake is low or high.