Artwork representing the most abundant protein in the blood plasma, the albumin (green particles). Albumin is produced by the liver from amino acids that have been absorbed from digested proteins. Albumin has several important functions. By binding to substances such as calcium, some hormones and drugs it prevents them from being filtered out by the kidneys and excreted in the urine. It is also important in regulating the plasma volume. An insufficient level of albumin in the blood plasma increases the movement of water from the bloodstream towards the surrounding tissues causing abnormal accumulation of fluid known as oedemas.