Vanadium, 24 Hour, Urine
Clinical Information Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test
The element vanadium, naturally found in minerals and rocks, is considered an essential element for mammals, although conclusive evidence for humans is lacking. Animal studies have shown that vanadium is essential for mammalian growth and reproduction, iron and lipid metabolism, and red blood cell production.
Vanadium is recovered from minerals or as a by-product of iron, titanium, and uranium refining. Vanadium pentoxide is used in the production of special steels, and is one of the common elements used to make orthopedic prosthetic devices. Vanadium compounds are used as catalysts for polypropylene production and synthesis of inorganic and organic chemicals. Vanadium compounds are used in dyes, photography, ceramics, and in the production of special glasses. Vanadium also is a component of a fiber mesh prosthetic alloy.
The main source of vanadium intake for the general population is food, with an estimated daily intake of 20 mcg, of which most is excreted in the feces, without absorption. Absorption through the inhalation route results in more effective uptake. About 90% of blood vanadium is found in serum. The half-life in serum is not well documented, but it appears to be on the order of several days. Urine is the main route of excretion of absorbed vanadium. Urine monitoring for vanadium is considered a highly reliable indicator of recent exposure.
Vanadium has been recognized as an occupational hazard for more than 20 years. Elevated atmospheric vanadium levels can result from burning fossil fuels with high vanadium content. Inhalation and ingestion are the primary exposure routes. Vanadium exposure can result in a metallic taste and so-called "green tongue." Sensitization can result in asthma or eczema. Vanadium intoxication is effectively treated with ascorbic acid.
Detecting vanadium exposure
Values >1.0 mcg/specimen represent possible environmental or occupational exposure.
Values >5.0 mcg/specimen indicate probable vanadium exposure.
Cautions Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances
Specimen collection procedures require special collection containers, rigorous attention to ultraclean specimen collection and handling procedures, and analysis in an ultraclean facility. Unless all of these procedures are followed, increased urine vanadium results may be an incidental and misleading finding.
Currently, there is no clinical data to support the need for taking vanadium supplements such as vanadyl sulfate, vanadium colloid, or any other form. This test provides no information regarding any theoretical vanadium deficiency.
This test should be ordered only when there is reason to suspect vanadium exposure. There is still controversy as to the effects of industrial exposure on the body, and toxicity data is extremely limited.
Although vanadium appears to be an essential trace element in humans, its role, if any, is not clearly defined and this test is not useful for nutritional assessment.
Currently, there is no evidence to suggest the clinical utility of monitoring vanadium levels in dialysis patients. If there is concern about prosthetic joints such as fiber mesh alloy deterioration, aluminum can be measured.
High concentrations of gadolinium and iodine are known to interfere with most metals tests. If either gadolinium- or iodine-containing contrast media has been administered, a specimen cannot be collected for 96 hours.
There is no clear evidence to support the preference for either serum or urine as the specimen of choice for monitoring exposure. Under no circumstances is hair or nails testing advisable.
Reference Values Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.
Normal: <1.0 mcg/specimen
Clinical References Provides recommendations for further in-depth reading of a clinical nature
Sabbioni E, Kucera J, Pietra R, Versterberg O: A critical review on normal concentrations of vanadium in human blood, serum, and urine. Sci Tot Environ 1996 September 20;188:49-58