3. Which of the following is the active form of calcium in the body? (AIPG 2008)
|B||Complexed with phosphate|
|C||Coplexed with oxalates|
|D||Bound to albumin|
There is approximately 1 kg of calcium in the human body. About 99% exists in the bone and 1%in the extra cellular fluid. Plasma calcium exists in 3 forms:
a. Complexed with organic acids b. Protein bound c. Ionized
The ionized calcium which is maintained at a concentration between 1.1 and 1.3 mmol/L is biologically the most active fraction. The organism has very little tolerance for significant deviation from this normal range. If the ionic calcium levels fall the organism develops hyper excitability and develops tetanic convulsions. A marked elevation may result in death owing to muscle paralysis and coma.