Calcium is the most abundant mineral in the human body. The average adult body contains approximately 25000 mmol (1 kg) of which 99% is bound in the skeleton.
The skeleton serves as a bank of minerals for the body. The body can borrow from the skeletal stores when blood calcium levels drop and return calcium to bones as needed.
In circulating blood, calcium concentration is typically 2.25-2.5 mmol. Approximately 40-45% of this quantity is bound to plasma protein, approx 8-10% is complexed with ion such as citrate and 45-50% is dissociated as free ions.
About 10-40% of dietary calcium is absorbed in the small intestine with the help of vitamin D. The level of calcium absorption from dietary sources drops to 7 in post-menopausal women. The body will absorb more calcium if there is a deficiency.
Numerous end organs participate in the regulation of calcium. The gastrointestinal tract and kidney, along with bone, are major regulators of calcium balance.
Calcium receptors in liver may monitor the calcium concentration in plasma, sending signals to the brain and affecting other peripheral sites in the body.
Calcium has many important functions in the body.
Calcium functions including:
#Calcium is responsible for construction, formation and maintenance of bone and teeth. Bone consists of osteoid, a collagenous organic matrix, on which is deposited complex inorganic hydrated calcium salts know as hydroxyapatites.
#Calcium is a vital component in blood clot formation and also helps in wound healing.
#Calcium helps to control blood pressure, nerve transmission
#Co-factor for enzymes and proteins that regulate digestion, energy, and fat metabolism.
#Calcium helps to transport ions (electrically charged particles) across the membrane.
#Calcium is essential for muscle contraction and relaxation
#Maintain normal heart rhythm
#Calcium assists in maintaining all cells and connective tissues in the body.
#Calcium may be helpful to reduce the incidence of premature heart disease, especially if adequate intakes of magnesium are also maintained.
#Calcium may help to prevent periodontal disease (gum disease).
#Initiation of DNA synthesis
#Cell signaling and neurotransmitter release
Calcium Deficiency
Calcium deficiency in conjunction with high sodium intake is related to a higher risk of hypertension. The deficiency can lead to loss of calcium from the bone (initially from the jaw and the backbone), which can lead to deformity.
Calcium deficiency also can cause extreme nerve sensitivity, muscle spasms, and leg cramps (called tetany) at very low levels in the blood.
Calcium in human body
