- Last Update On : 2013-10-06
Albumin comprises 60% of the total serum protein and 60 to 80% of colloid osmotic pressure. Serum albumin is synthesized solely by the liver and has several physiological functions: transport of low molecular weight substances such as calcium, hormones, and drugs; binding of toxic heavy metal ions; maintenance of colloid osmotic pressure; and provision of a protein reserve. Normally, about 4% of the total body albumin is replenished each day. The rate of production is dependent on the supply of amino acids, plasma oncotic pressure, inhibitory cytokine (especially IL-6) concentration, and the number of functioning hepatocytes. Circulating half-life of plasma albumin is 19 to 21 days.
Plasma albumin levels are low in neonates, typically between 2.8 and 4.4 g/dL. Adult levels are reached after the first week of life. Levels are slightly higher in children (4.5 – 5.5 g/dL) between the age of 6 years and young adulthood. Thereafter, levels decline to typical adult levels. Album