Seven trace minerals are known to be essential to human function even though they are present in minute quantities in the body. These essential minerals are cobalt, copper, iodine, iron, manganese, molybdenum, and zinc.
Cobalt is a constituent of vitamin B12 and is essential to the formation of red blood cells. Copper participates in cytochrome oxidation of tissue cells for energy production, promotes absorption of iron from the intestines and transfer from tissues to plasma, and is essential to hemoglobin formation. It also promotes bone and brain tissue formation and supports the maintenance of myelin. Iodine is an essential component for the synthesis of thyroid hormones. Iron, which is discussed in Chapter 1 - Hematology and Tests of Hematopoietic Function, is an essential component of hemoglobin.
Manganese functions as a coenzyme in urea formation and in the metabolism of proteins, fats, and carbohydrates. Molybdenum facilitates the enzymatic action of xanthine oxidase and liver aldehyde oxidase in purine catabolism and functions in the formation of carboxylic acid. Zinc is an essential component of cellular enzymes such as alkaline phosphatase, carbonic anhydrase, lactic dehydrogenase, and carboxypeptidase, which function in protein and carbohydrate metabolism. It also aids in the storage of insulin, functions in deoxyribonucleic acid (DNA) replication, assists in carbon dioxide exchange, promotes body growth and sexual maturation, and may affect lymphocyte formation and cellular immunity.
Other trace minerals are found in the body, but their functions remain unclear. These minerals include chromium, fluorine, lithium, arsenic, cadmium, nickel, silicon, tin, and vanadium.
Deficiencies of trace minerals are likely only in individuals dependent on parenteral nutrition, because the normal diet provides adequate intake. Elevated blood levels are usually caused by environmental contamination, either in industrial settings or through water pollution.
| Conventional Units | SI Units | |
|---|---|---|
| Cobalt | 1 µg/dL | 1.7 nmol/L |
| Copper | 130-230 µg/dL | 20.41-36.11 µmol/L |
| Iodine (protein-bound) | 4-8 µg/dL | |
| Manganese | 4-20 mg/dL | |
| Zinc | 50-150 µg/dL | 7.6-23.0 µmol/L |
| Chromium | 0.3-0.85 µg/L | 5.7-16.3 nmol/L |
Nursing Care Before the Procedure
Client preparation is the same as that for any test involving the collection of a peripheral blood sample (see Appendix I).
A venipuncture is performed and the sample collected in a metal-free tube. The sample is handled gently to avoid hemolysis and transported immediately to the laboratory.
Nursing Care After the Procedure
Care and assessment after the procedure are the same as for any test involving the collection of a peripheral blood sample.