iarjcmbIARJCMBIARJCMB2789-6005https://doi.org/10.47310/iarjcmb.2023.v03i02.005Comparison and Assessment of Serum Calcium Level and Prothrombin Time in Above and Below 40 Age Group PeopleSenthilKumar.TMs.Reshma.JManju.MMalavika.PCalcium is one of the body's electrolytes, which are minerals that carry an electric charge when dissolved in body fluids such as blood. Calcium is a mineral most often associated with healthy bones and teeth, although it also plays an important role in blood clotting, helping muscles to contract, and regulating normal heart rhythms and nerve functions. About 99% of the body’s calcium is stored in bones, and the remaining 1% is found in blood, muscle, and other tissues. If people do not consume enough calcium, too much calcium is mobilized from the bones, weakening them. Osteoporosis can result. Without sufficient calcium levels, thrombocytes (blood cells that play a key role in blood clot formation) would not be able to release their contents during an acute blood loss, which could lead to death Ionized or free calcium is the most active form calcium present in our body. Only the ionized or free calcium (Ca++) is the physiologically active form of calcium in our body. It is the form that triggers various biological functions and responses, such as blood coagulation, muscle contraction and hormone release. Calcium exists in 3 distinct forms. Approximately 15% is complexed calcium bound to organic and inorganic anions, 40% is bound to albumin, and the remaining 45% circulates as free ionized calcium. A randomized cross-sectional study of 120 patients comprising of 61 females and 59 males who were selected on the basis of age group (below and above 40 age group) for the study samples who attended Medicine OPD and IPD in A.C.S Medical college and hospital . After getting consent from the patients’ blood sample was collected. Serum was separated, and then calcium estimated by Arsenazo III method. Out of 120 samples, Out of 60 peoples included in below 40 age group, 60 people (100%) people had normal calcium and normal prothrombin time. Out of 60 peoples included in above 40 age group, 30 people (50%) people had normal calcium and normal prothrombin time and 30 (50 %) people had hypocalcemia and increased prothrombin time.