Calcium pump Calcium pump Calcium pumps are a family of ion transporters found in the cell membrane of all animal cells. They are responsible for the active transport of calcium out of the cell for the maintenance of the steep Ca electrochemical gradient across the cell membrane. Calcium pumps play a crucial role in proper cell signalling by keeping the intracellular calcium concentration roughly 10,000 times lower than the extracellular concentration. Failure to do so is one cause of muscle cramps. The plasma membrane Ca ATPase and the sodium-calcium exchanger are together the main regulators of intracellular Ca concentrations. Ca has many
Calcium supplement citrate, calcium gluconate, calcium lactate and calcium phosphate. Vitamin D is added to some calcium supplements. Proper vitamin D status is important because vitamin D is converted to a hormone in the body, which then induces the synthesis of intestinal proteins responsible for calcium absorption. For U.S. dietary supplement and food labeling purposes the amount in a serving is expressed in milligrams and as a percent of Daily Value (%DV). The weight is for the calcium part of the compound - for example, calcium citrate - in the supplement. For calcium labeling purposes 100% of the Daily Value was 1000