Clinical Chemistry

Description  

Alanine aminotransferase (ALT) is an enzyme found mostly in the cells of the liver and kidney. Much smaller amounts of it are also found in the heart and muscles. In healthy individuals, ALT levels in the blood are low. When the liver is damaged, ALT is released into the bloodstream, usually before more obvious signs of liver damage occur. This makes ALT a useful test for detecting liver damage. 

Sample: Blood (serum) 

Reference  

• Female: less than 34 U/l  
• Male: less than 45 U/l 

Frequency: Daily 

Description 

Albumin is a protein made by the liver. It makes up about 60% of the total protein in the blood and plays many roles. It keeps fluid from leaking out of blood vessels; nourishes tissues; and transports hormones, vitamins, drugs, and ions like calcium throughout the body. The concentration of albumin in the blood is a reflection of liver function and of nutritional status. This test measures the level of albumin in the blood. The test is executed to screen for and help diagnose a liver disorder or kidney disease; sometimes to evaluate nutritional status, especially in hospitalized patients. 

Sample: Blood (serum) 

Reference: Between 3.4 g/dl and 5.1 g/dl 

Frequency: Daily

Description 

Alkaline phosphatase (ALP) is an enzyme found in several tissues throughout the body, including liver, bone, kidney, bowel (intestine), and in the placenta of women who are pregnant. The highest concentrations of ALP are present in the cells that comprise bone and the liver. This test measures the level of ALP in the blood; it screens for or monitors treatment for a liver or bone disorder. 

Sample: – – –  

Reference  

• Female: less than 98 U/l 
• Male: less than 171 U/l 

Frequency: – – – 

Description 

This test is performed primarily to diagnose and monitor acute pancreatitis; also sometimes to diagnose and monitor chronic pancreatitis or other pancreatic diseases. Amylase is one of several enzymes produced by the pancreas to help digest carbohydrates. This test measures the amount of amylase in the blood or urine or sometimes in peritoneal fluid. Amylase is usually present in the blood and urine in small quantities. When cells in the pancreas are injured, as happens with pancreatitis, or when the pancreatic duct is blocked by a gallstone or by a pancreatic tumor in rare cases, increased amounts of amylase are released into the blood. 

Sample: Blood (serum); urine 

Reference: Less than 107 U/l 

Frequency: Daily 

Description 

Apolipoprotein A-I (apo A-I) is a protein that has a specific role in the metabolism of lipids and is the main protein component in high-density lipoprotein (HDL, the “good cholesterol”). This test measures the amount of apo A-I in the blood. Apolipoprotein A-I (apo A-I) may be ordered, along with other lipid tests, as part of a profile to help determine a person’s risk of developing cardiovascular disease (CVD). It may be used as an alternative to a high-density lipoprotein (HDL) test, but it is not generally considered “better” or more informative than HDL and is not ordered routinely. 

Sample: Blood (serum) 

Reference:  

• Female: between 107 mg/dl and 205 mg/dl  
• Male: between 107 mg/dl and 177 mg/dl 

Frequency: Twice a week 

Description 

Apolipoprotein B-100 (also called apolipoprotein B or apo B) is a protein that is involved in the metabolism of lipids and is the main protein constituent of lipoproteins such as very low-density lipoprotein (VLDL) and low-density lipoprotein (LDL, the “bad cholesterol”). This test measures the amount of apo B in the blood. The apolipoprotein B (apo B) test is used, along with other lipid tests, to help determine an individual’s risk of developing cardiovascular disease (CVD). 

Sample: Blood (serum) 

Reference:

• Female: between 52 mg/dl and 129 mg/dl 
• Male: between 60 mg/dl and 138 mg/dl 

Frequency: Twice a week 

Description 

Aspartate aminotransferase (AST) is an enzyme found in cells throughout the body but mostly in the heart and liver and, to a lesser extent, in the kidneys and muscles. In healthy individuals, levels of AST in the blood are low. When liver or muscle cells are injured, they release AST into the blood. This makes AST a useful test for detecting liver damage. 

Sample: Blood (serum) 

Reference  

• Female: less than 31 U/l 
• Male: less than 35 U/l 

Frequency: Daily 

Description 

This test is executed as part of an electrolyte panel to identify or monitor an electrolyte imbalance or acid-base (pH) imbalance. The total CO2 test measures the total amount of carbon dioxide in the blood, which occurs mostly in the form of bicarbonate (HCO3-). Bicarbonate is a negatively charged ion that is excreted and reabsorbed by the kidneys. It is used by the body to help maintain the body’s acid-base balance (pH) and secondarily to work with sodium, potassium, and chloride to maintain electrical neutrality at the cellular level. 

Sample: Blood (serum) 

Reference: Between 22.0 mmol/l and 29.0 mmol/l 

Frequency: Daily

Description 

Neonatal jaundice or Neonatal hyperbilirubinemia, or Neonatal icterus is a yellowing of the skin and other tissues of a newborn infant. It is not uncommon to see high total and unconjugated bilirubin levels in newborns. This is sometimes called physiologic jaundice of the newborn and is due to immaturity of the newborn’s liver. This situation usually resolves itself within a few days. 

Sample: Blood (serum) 

Reference: – – – 

Frequency: Daily 

Description 

Bilirubin is an orange-yellow pigment, a waste product primarily produced by the normal breakdown of heme, a substance found mainly in the protein hemoglobin in red blood cells (RBCs). It is ultimately processed by the liver to allow its elimination from the body. This test measures the amount of bilirubin in the blood in order to evaluate liver function or to help diagnose anemia caused by the increased destruction of RBCs. 

Sample: Blood (serum) 

Reference: Less than 1.2 mg/dl 

Frequency: Daily 

Description 

Calcium is the most abundant and one of the most important minerals in the body. It is essential for cell signaling and the proper functioning of muscles, nerves, and the heart. Calcium is needed for blood clotting and is crucial for the formation, density, and maintenance of bones. This test measures the amount of calcium in the blood or urine. 

Sample: Blood (serum); urine 

Reference: Between 2.15 mmol/l and 2.60 mmol/l 

Frequency: Daily 

Description 

Chloride is an electrolyte. It is a negatively charged ion that works with other electrolytes, such as potassium, sodium, and bicarbonate, to help regulate the amount of fluid in the body and maintain the acid-base balance. Chloride is present in all body fluids but is found in the highest concentration in the blood and in the fluid outside of the body’s cells. Most of the time, chloride concentrations mirror those of sodium, increasing and decreasing for the same reasons and in direct relationship to sodium. When there is an acid-base imbalance, however, blood chloride levels can change independently of sodium levels as chloride acts as a buffer. It helps to maintain electrical neutrality at the cellular level by moving into or out of the cells as needed. This test helps determine if there is a problem with your body’s electrolyte balance or acid-base balance and to monitor treatment. 

Sample: Blood (serum); urine 

Reference: For blood (serum): between 98 mmol/l and 107 mmol/l  

Frequency: Daily 

Description 

Cholesterol is different from most tests in that it is not used to diagnose or monitor a disease but is used instead to estimate risk of developing a disease — specifically heart disease. Because high blood cholesterol has been associated with hardening of the arteries (atherosclerosis), heart disease, and a raised risk of death from heart attacks, cholesterol testing is considered a routine part of preventive health care. Cholesterol is a substance (a steroid) that is essential for life. It forms the membranes for cells in all organs and tissues in the body. It is used to make hormones that are essential for development, growth, and reproduction. It forms bile acids that are needed to absorb nutrients from food. 

Sample: Blood (serum) 

Reference: Less than 200 mg/dl 

Frequency: Daily

Description 

Cholinesterases are enzymes that are involved in helping the nervous system to function properly. Cholinesterase tests measure the activity of these enzymes. It helps determine if you have been exposed to and/or poisoned by certain organophosphate chemicals found in pesticides or to monitor cholinesterase levels if you work with pesticides. Sometimes it helps identify individuals with inherited pseudocholinesterase deficiency before they are given anesthesia with the muscle relaxant succinylcholine or determine the cause of prolonged apnea after surgical anesthesia. 

Sample: Blood (serum) 

Reference: Between 4100 U/l and 9900 U/l 

Frequency: Daily 

Description 

This test measures the amount of creatine kinase (CK) in the blood. Creatine kinase is an enzyme found in the heart, brain, skeletal muscle, and other tissues. The small amount of CK that is normally in the blood comes primarily from skeletal muscles. Increased amounts of CK are released into the blood when there is muscle damage. 

Sample: Blood (serum) 

Reference:

• Female: less than 145 U/l 
• Male: less than 171 U/l 

Frequency: Daily 

Description 

C-reactive protein (CRP) is an acute phase reactant, a protein made by the liver and released into the bloodstream within a few hours after tissue injury, the start of an infection, or other cause of inflammation. Markedly increased levels are observed, for example, after trauma, heart attack, with autoimmune disorders, and with serious bacterial infections like sepsis. The level of CRP can jump a thousand-fold in response to an inflammatory condition, and its rise in the blood can precede pain, fever, or other clinical indicators. The test measures the amount of CRP in the blood and can be valuable in detecting inflammation due to acute conditions or in monitoring disease activity in chronic conditions. 

Sample: Blood (serum) 

Reference: Less than 1.00 mg/dl 

Frequency: Daily 

Description 

This test measures the amount of creatinine in the blood and/or urine. Creatinine is a waste product produced by muscles from the breakdown of a compound called creatine. Creatine is part of the cycle that produces energy needed to contract muscles. Both creatine and creatinine are produced by the body at a relatively constant rate. Almost all creatinine is excreted by the kidneys, so blood levels are usually a good indicator of how well the kidneys are working. The test is performed to determine if your kidneys are functioning normally and to monitor treatment for kidney disease. 

Sample: Blood (serum); urine 

Reference  

• Female: between 6.0 mg/dl and 11.0 mg/dl 
• Male: between 7.0 mg/dl and 13.0 mg/dl 

Frequency: Daily 

Description 

Ferritin is an iron-containing protein and is the primary form of iron stored inside of cells. The small quantity of ferritin that is released into the blood is a reflection of the amount of total iron stored in the body. This test measures the amount of ferritin in the blood. In healthy people, about 70% of the iron absorbed by the body is incorporated into the hemoglobin of red blood cells. Most of the remaining 30% is stored as ferritin or as hemosiderin, a complex of iron, proteins, and other materials. Ferritin and hemosiderin are present primarily in the liver but also in the bone marrow, spleen, and skeletal muscles. 

Sample: Blood (serum) 

Reference  

• Female: between 9 ng/ml and 120 ng/ml 
• Male: between 18 ng/ml and 370 ng/ml 

Frequency: Twice a week 

Description 

This test is primarily ordered to detect deficiencies and to help diagnose the cause of certain anemias. Vitamin B12 and folate are both part of the B complex of vitamins. Both B12 and folate are necessary for normal RBC formation, tissue and cellular repair, and DNA synthesis. B12 is important for nerve health, while folate is necessary for cell division such as is seen in a developing fetus. A deficiency in either B12 or folate can lead to macrocytic anemia. The tests Vitamin B12 and folate are primarily ordered to detect deficiencies and to help diagnose the cause of certain anemias. They are also performed to help evaluate the general health and nutritional status of a person with signs of significant malnutrition or dietary malabsorption. 

Sample: Blood (serum) 

Reference: Between 3.0 ng/ml and 17.0 ng/ml 

Frequency: Twice a week 

Description 

Fructosamine is a compound that is formed when glucose combines with protein. The fructosamine test is a measurement of this glycated protein. When glucose levels in the blood are elevated over a period of time, glucose molecules permanently combine with proteins in the blood in a process called glycation. Affected proteins include albumin, the principal protein in the blood, other serum proteins, and hemoglobin, the major protein found inside red blood cells (RBCs). The more glucose that is present in the blood, the greater the amount of glycated proteins that are formed. These combined molecules persist for the life of the protein or RBC and provide a record of the average amount of glucose that has been present in the blood over that time period. 

Sample: Blood (serum) 

Reference: Between 1.60 mmol/l and 2.75 mmol/l 

Frequency: Daily 

Description 

Glucose-6-phosphate dehydrogenase (G6PD) is an enzyme involved in energy production. It is found in all cells including red blood cells (RBCs) and helps protect them from certain by-products of cellular metabolism. A deficiency in G6PD causes RBCs to become more vulnerable to breaking apart (hemolysis) when exposed to certain substances. This test measures the amount of G6PD enzyme in RBCs to help diagnose an inherited G6PD deficiency. 

Sample: Blood  

Reference: Normal 

Frequency: Daily 

Description 

Gamma-glutamyl transferase (GGT) is an enzyme that is found in many organs, such as the kidney, liver, gallbladder, spleen, and pancreas. Among these, the liver is the main source of GGT in the blood. This test measures the level of GGT in a blood sample. Normally, GGT is present in low levels, but when the liver is injured, the GGT level can rise. The GGT test is performed to evaluate for a possible liver disease or bile duct disease or to differentiate between liver and bone disease as a cause of elevated alkaline phosphatase (ALP) and sometimes to screen for or monitor alcohol abuse. 

Sample: Blood (serum) 

Reference  

• Female: less than 38 U/l 
• Male: less than 55 U/l 

Frequency:  Daily 

Description 

This test measures the amount of glucose in the blood or urine. Glucose is the primary energy source for the body’s cells and the only energy source for the brain and nervous system. A steady supply must be available for use, and a relatively constant level of glucose must be maintained in the blood. Blood glucose is often measured as part of a group of tests and is done to screen for diabetes and for pre-diabetes (moderately increased blood glucose levels that indicate an increased risk of developing type 2 diabetes). 

Sample: Blood (serum) 

Reference: – – – 

Frequency: Daily 

Description 

This test measures the amount of glucose in the blood or urine. Glucose is the primary energy source for the body’s cells and the only energy source for the brain and nervous system. A steady supply must be available for use, and a relatively constant level of glucose must be maintained in the blood. Blood glucose is often measured as part of a group of tests and is done to screen for diabetes and for pre-diabetes (moderately increased blood glucose levels that indicate an increased risk of developing type 2 diabetes). This test is performed two (2) hours after breakfast. 

Sample:  Blood (serum) 

Reference:  Between 140 mg/dl and 200 mg/dl 

Frequency:  Daily

Description 

This test measures the amount of glucose in the blood or urine. Glucose is the primary energy source for the body’s cells and the only energy source for the brain and nervous system. A steady supply must be available for use, and a relatively constant level of glucose must be maintained in the blood. Blood glucose is often measured as part of a group of tests and is done to screen for diabetes and for pre-diabetes (moderately increased blood glucose levels that indicate an increased risk of developing type 2 diabetes). This test is performed two (2) hours after lunch. 

Sample:  Blood (serum) 

Reference: Between 140 mg/dl and 200 mg/dl 

Frequency: Daily 

Description 

This test measures the amount of glucose in the blood or urine. Glucose is the primary energy source for the body’s cells and the only energy source for the brain and nervous system. A steady supply must be available for use, and a relatively constant level of glucose must be maintained in the blood. Blood glucose is often measured as part of a group of tests and is done to screen for diabetes and for pre-diabetes (moderately increased blood glucose levels that indicate an increased risk of developing type 2 diabetes). The client must be fasting for this test to be performed. 

Sample:  Blood (serum) 

Reference:  Between 65 mg/dl and 110 mg/dl 

Frequency:  Daily 

Description 

High-density lipoprotein (HDL cholesterol, HDL-C) is one of the classes of lipoproteins that carry cholesterol in the blood. HDL-C consists primarily of protein with a small amount of cholesterol. It is considered to be beneficial because it removes excess cholesterol from tissues and carries it to the liver for disposal. Hence, HDL cholesterol is often termed “good” cholesterol. The test for HDL cholesterol measures the amount of HDL-C in blood. 

Sample:  Blood (serum) 

Reference: Between 35 mg/dl and 70 mg/dl 

Frequency: Daily 

Description 

This test is performed to monitor a person’s diabetes and to aid in treatment decisions. The A1c test evaluates the average amount of glucose in the blood over the last 2 to 3 months. It does this by measuring the concentration of glycated (also often called glycosylated) hemoglobin A1c. Hemoglobin is an oxygen-transporting protein found inside red blood cells (RBCs). There are several types of normal hemoglobin, but the predominant form – about 95-98% – is hemoglobin A. As glucose circulates in the blood, some of it spontaneously binds to hemoglobin A. The hemoglobin molecules with attached glucose are called glycated hemoglobin. The higher the concentration of glucose in the blood, the more glycated hemoglobin is formed. Once the glucose binds to the hemoglobin, it remains there for the life of the red blood cell – normally about 120 days. The predominant form of glycated hemoglobin is referred to as HbA1c or A1c. 

Sample:  Blood  

Reference:  Between 4.0 % and 6.2 % 

Frequency: Daily 

Description 

Lactate dehydrogenase (LD or LDH) is an enzyme involved in energy production that is found in almost all of the body’s cells, with the highest levels found in the cells of the heart, liver, muscles, kidneys, lungs, and in blood cells; bacteria also produce LD. This test measures the level of LD in the blood or sometimes other body fluids. This test is performed to help detect a condition causing tissue damage, such as a blood or liver disease, and to monitor its progress; to help stage, determine prognosis, and/or response to treatment of certain cancers; to help evaluate body fluid (other than blood). 

Sample:  Blood (serum) 

Reference  

• Female: less than 247 U/l 
• Male: less than 248 U/l 

Frequency: Daily 

Description 

Low-density lipoprotein (LDL cholesterol, LDL-C) is one type of lipoprotein that carries cholesterol in the blood. LDL-C consists mostly of cholesterol and similar substances with a small amount of protein. LDL cholesterol is considered to be undesirable and is often call “bad” cholesterol because it deposits excess cholesterol in blood vessel walls and contributes to hardening of the arteries and heart disease. 

Sample:  Blood (serum) 

Reference:  Between 65 mg/dl and 200 mg/dl 

Frequency: Daily 

Description 

This test is performed primarily to diagnose and monitor acute pancreatitis; also sometimes to diagnose and monitor chronic pancreatitis or other pancreatic diseases. Lipase is one of several enzymes produced by the pancreas to help digest dietary fats. This test measures the amount of lipase in the blood. Lipase is transported through the pancreatic duct and into the first part of the small intestine (duodenum), where it helps break down dietary triglycerides (a form of fat) into fatty acids. The pancreas is the primary source of lipase. 

Sample:  Blood (serum) 

Reference:  Between 10 U/l and 60 U/l 

Frequency:  Daily 

Description 

Magnesium is a mineral that is vital for energy production, muscle contraction, nerve function, and the maintenance of strong bones. It comes into the body through the diet and is absorbed by the small intestine and colon. Magnesium is stored in the bones, cells, and tissues. Normally, only about 1% of total body magnesium is present in the blood and this makes it difficult to get an accurate measurement of total magnesium content from blood tests alone. However, this test is still useful for evaluating a person’s magnesium status. 

Sample: Blood (serum) 

Reference:  Between 0.60 mmol/l and 1.05 mmol/l 

Frequency:  Daily 

Description 

These tests measure the concentration of B-type natriuretic peptide (BNP) or N-terminal pro b-type natriuretic peptide (NT-proBNP) in the blood in order to detect and evaluate heart failure. BNP was initially called brain natriuretic peptide because it was first found in brain tissue (and to distinguish it from a similar protein made in the atria, or upper chambers, of the heart, termed ANP). BNP is actually produced primarily by the left ventricle of the heart (the heart’s main pumping chamber). It is associated with blood volume and pressure and with the work that the heart must do in pumping blood throughout the body. Small amounts of a precursor protein, pro-BNP, are continuously produced by the heart. Pro-BNP is then cleaved to release the active hormone BNP and an inactive fragment, NT-proBNP, into the blood. 

Sample:  Blood (serum) 

Reference:  Less than 125 pg/ml 

Frequency:  Twice a week 

Description 

This test is performed to evaluate the level of phosphorus in your blood and to aid in the diagnosis of conditions known to cause abnormally high or low levels of phosphorus. Phosphorus is a mineral that combines with other substances to form organic and inorganic phosphate compounds. The terms phosphorus and phosphate are often used interchangeably when talking about testing, but it is the amount of inorganic phosphate in the blood that is measured with a serum phosphorus/phosphate test. Phosphates are vital for energy production, muscle and nerve function, and bone growth. They also play an important role as a buffer, helping to maintain the body’s acid-base balance. 

Sample:  Blood (serum); urine 

Reference:  Between 0.60 mmol/l and 1.60 mmol/l 

Frequency: Daily 

Description 

This test measures the amount of potassium in the blood. Potassium is an electrolyte that is vital to cell metabolism and muscle function. Potassium, along with other electrolytes, helps regulate the amount of fluid in the body, stimulates muscle contraction, and maintains a stable acid-base balance. Potassium is present in all body fluids, but most potassium is found within your cells. Only about 2% is present in fluids outside the cells and in the liquid part of the blood (called serum or plasma). Because the blood concentration of potassium is so small, minor changes can have significant consequences. If potassium levels are too low or too high, there can be serious health consequences; a person may be at risk for developing shock, respiratory failure, or heart rhythm disturbances. An abnormal potassium level can alter the function of neuromuscular tissue; for example, the heart muscle may lose its ability to contract. 

Sample:  Blood (serum); urine 

Reference:  Between 25 mmol/24hrs and 100 mmol/24hrs 

Frequency:  Daily 

Description 

The total protein test measures the total amount of two classes of proteins found in the fluid portion of your blood. These are albumin and globulin. Albumin helps prevent fluid from leaking out of blood vessels. Globulins are an important part of your immune system. Proteins are important parts of all cells and tissues. This test is performed as part of a general health checkup, to determine the nutritional status or to screen for and help diagnose certain liver and kidney disorders as well as other diseases. 

Sample:  Blood (serum) 

Reference:  Between 6.4 g/dl and 8.3 g/dl 

Frequency:  Twice a week 

Description 

Iron is an essential trace element and nutrient that is necessary to maintain life. The serum iron test measures the amount of iron in the liquid portion of blood. Iron is absorbed from food and transported throughout the body by transferrin, a protein produced by the liver. Iron is necessary for the production of healthy red blood cells (RBCs). It is an important part of hemoglobin, the protein in RBCs that enables them to carry oxygen throughout the body. Iron is also used in the production of some proteins, including myoglobin and some enzymes. 

Sample:  – – – 

Reference:  Between 35 µg/dl and 140 µg/dl 

Frequency:  – – – 

Description 

Transferrin is the main protein in the blood that binds to iron and transports it throughout the body. The amount of transferrin that is available to bind to and transport iron is reflected in measurements of the total iron binding capacity (TIBC), unsaturated iron binding capacity (UIBC), or transferrin saturation. This test is performed to assess your body’s ability to transport iron in the blood. 

Sample:  Blood (serum) 

Reference:  Between 200 µg/dl and 400 µg/dl & between 20 % and 45 % 

Frequency:  Twice a week 

Description 

This test is performed to assess your body’s ability to transport iron in the blood. Transferrin is the main protein in the blood that binds to iron and transports it throughout the body. The amount of transferrin that is available to bind to and transport iron is reflected in measurements of the total iron binding capacity (TIBC), unsaturated iron binding capacity (UIBC), or transferrin saturation. This test is performed to assess your body’s ability to transport iron in the blood. 

Sample:  Blood (serum) 

Reference  

• Female: between 9 ng/ml and 120 ng/ml 
• Male: between 18 ng/ml and 370 ng/ml 

Frequency:  Twice a week 

Description 

Triglycerides are a form of fat and a major source of energy for the body. This test measures the amount of triglycerides in the blood. Most triglycerides are found in fat (adipose) tissue, but some triglycerides circulate in the blood to provide fuel for muscles to work. After a person eats, an increased level of triglycerides is found in the blood as the body converts the energy not needed right away into fat. Triglycerides move via the blood from the gut to adipose tissue for storage. High levels of triglycerides in the blood are associated with an increased risk of developing cardiovascular disease (CVD). 

Sample:  Blood (serum) 

Reference:  Between 35 mg/dl and 180 mg/dl 

Frequency:  Twice a week 

Description 

The troponins are a family of proteins found in skeletal and heart muscle (cardiac) fibers. There are three different types: troponin C (TnC), troponin T (TnT), and troponin I (TnI). Together, these three proteins regulate muscular contraction. Cardiac-specific troponins I and T (cTnI and cTnT) are troponins that are found only in the heart. They are normally present in very small to undetectable quantities in the blood. When there is damage to heart muscle cells, cardiac-specific troponins I and T are released into circulation. The more damage there is, the greater their concentration in the blood. The troponin test measures the amount of cardiac-specific troponin I or T in the blood and is used to help determine if an individual has suffered a heart attack. 

Sample:  Blood (serum) 

Reference:  Less than 0.030 µg/l 

Frequency:  Daily 

Description 

This test measures the amount of urea nitrogen in the blood. Urea is produced in the liver when protein is broken into its component parts (amino acids) and metabolized. This process produces ammonia, which is then converted into the less toxic waste product urea. Urea is released by the liver into the bloodstream and is carried to the kidneys, where it is filtered out of the blood and excreted in the urine. Since this is an ongoing process, there is usually a small but stable amount of urea nitrogen in the blood. 

Sample:  Blood (serum); urine 

Reference:  Between 13 mg/dl and 43 mg/dl 

Frequency:  Daily 

Description 

Uric acid is produced by the breakdown of purines. Purines are nitrogen-containing compounds found in the cells of the body, including our DNA. As cells get old and die, they break down, releasing purines into the blood. To a lesser extent, purines may come from the digestion of certain foods, such as liver, anchovies, mackerel, dried beans and peas and certain alcoholic drinks, primarily beer. Most uric acid is removed from the body by the kidneys and is excreted in the urine, with the remainder eliminated in the stool. This test measures the level of uric acid in the blood or urine. If too much uric acid is produced or not enough is excreted, it can accumulate in the body, causing increased levels in the blood (hyperuricemia). The presence of excess uric acid can cause gout, a condition characterized by inflammation of the joints due to the formation of uric acid crystals in the joint (synovial) fluid. Excess uric acid can also be deposited in tissues such as the kidney, leading to kidney stones or kidney failure. The accumulation of too much uric acid is due to either increased production, decreased elimination, or a combination of both. Elevated levels of uric acid can occur when there is an increase in cell death, as seen with some cancer therapies or, rarely, as an inherited tendency to overproduce uric acid. Decreased elimination of uric acid is often a result of impaired kidney function due to kidney disease. 

Sample:  Blood (serum); urine 

Reference  

• Female: between 6.0 mg/dl and 11.0 mg/dl 
• Male: between 7.0 mg/dl and 13.0 mg/dl 

Frequency:  Daily 

Description 

Vitamin B12 and folate are both part of the B complex of vitamins. Both B12 and folate are necessary for normal RBC formation, tissue and cellular repair, and DNA synthesis. B12 is important for nerve health, while folate is necessary for cell division such as is seen in a developing fetus. A deficiency in either B12 or folate can lead to macrocytic anemia. The tests Vitamin B12 and folate are primarily ordered to detect deficiencies and to help diagnose the cause of certain anemias. They are also performed to help evaluate the general health and nutritional status of a person with signs of significant malnutrition or dietary malabsorption. 

Sample:  Blood (serum) 

Reference:  Between 176 pg/ml and 948 pg/ml 

Frequency:  Twice a week