PRINCIPLE
At alkaline pH values, serum calcium forms a coloured complex with o-cresolphthalein, 8-hydroxyquinolein is included in the reagent as a chelating agent of magnesium ions which can interfere with the reaction.
DIAGNOSTIC USE
Calcium is the most abundant cation in the human body (99%) and is distributed mainly in the bones.
High calcium levels are found in the primary and tertiary hyperparathyroidism, cancer diseases (metastatic breast carcinoma, kidney or lung, leukemia, multiple myeloma), vitamin D intoxication, increased renal retention, sarcoidosis, osteoporosis, thyrotoxicosis.
Low calcium levels can be attributed to renal failure, hypoparathyroidism, vitamin D defi ciency, malnutrition or malabsorption.
Single test result could not be used to make a clinical diagnosis. It should integrate clinical and laboratory data.