The essentials of calcium, magnesium and phosphate metabolism: part I. Physiology.

摘要: Objective To review the components of calcium, phosphate and magnesium metabolism that are relevant to critically ill patient in a two-part presentation. Data sources A articles reported on disorders patient. Summary Calcium, have important intracellular extracellular functions with their often linked through common hormonal signals. predominant portion total body calcium is unionised within bone serves an structural function. Intracellular ionised changes secretory excitatory roles. The carefully regulated by parathyroid hormone vitamin D, whereas calcitonin secreted largely response hypercalcaemia. Phosphorous needed for structure although it also has role cell wall structure, energy storage as ATP, oxygen transport acid-base balance. Ionised far controls PTH secretion, indirectly urinary excretion. When plasma increases, tubular reabsorption increases up maximum (TmPO4), thereafter excreted. minimum oral requirement about 20 mmol/day. Magnesium predominantly ion acts metallo-coenzyme more than 300 transfer reactions thus critical transfer, utilisation body. Extracellular concentrations controlled kidneys renal (TmMg) controlling concentration. Conclusions In metabolism, disturbed alteration intake, increased liberation from damaged tissue reduced excretion (e.g. during failure), causing alterations subsequent disordered organ