Detecting vanadium toxicity
Monitoring metallic prosthetic implant wear
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 RBC 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. 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. Although there is minimal evidence for the nature of vanadium complexation in the body, research suggests transferrin will bind available ionized vanadium.
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.
Vanadium has been recognized as an occupational hazard for >20 years. Elevated atmospheric vanadium levels can result from burning fossil fuels with a 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.
Increased vanadium serum concentrations are observed in dialysis patients and those with compromised renal function since the kidney is primarily responsible for vanadium elimination. Elevated serum vanadium levels have been observed in patients with joint replacements; concentrations are likely to be increased above the reference range in patients with metallic joint prosthesis. Prosthetic devices produced by Zimmer Company and Johnson and Johnson typically are made of aluminum, vanadium, and titanium. Prosthetic devices produced by Depuy Company, Dow Corning, Howmedica, LCS, PCA, Osteonics, Richards Company, Tricon, and Whiteside typically are made of chromium, cobalt, and molybdenum. This list of products is incomplete, and these products change occasionally; see prosthesis product information for each device for composition details.
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 ng/mL
Values <1.0 ng/mL are normal. Values >5.0 ng/mL indicate probable exposure.
Prosthesis wear is known to result in increased circulating concentration of metal ions.(2-3) Modest increase (1-2 ng/mL) in serum vanadium concentration is likely to be associated with a prosthetic device in good condition. Serum concentrations >5 ng/mL in a patient with a vanadium-based implant suggest significant prosthesis wear. Increased serum trace element concentrations in the absence of corroborating clinical information do not independently predict prosthesis wear or failure.
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 serum vanadium results may be an incidental and misleading finding.
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 either dialysis patients or those with prosthetic joints. In cases where the fiber mesh alloy has deteriorated, aluminum can be measured.
There is no clear evidence to support the preference for either serum or urine as the specimen of choice for monitoring exposure. Under no circumstance is hair or nail testing advisable.
Due to possible contamination or binding of vanadium with anticoagulants, plasma testing is not recommended.
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.
Clinical Reference Provides recommendations for further in-depth reading of a clinical nature
1. Liu TK, Liu SH, Chang CH, Yang RS: Concentration of metal elements in the blood and urine in the patients with cementless total knee arthroplasty. Tohoku J Exp Med 1998 August;185:253-262
2. Lhotka C, Szekes T, Stefan I, et al: Four-year study of cobalt and chromium blood levels in patients managed with two different metal-on-metal total hip replacements. J Orthop Res 2003 March;21:189-195