Detecting vanadium toxicity

Monitoring metallic prosthetic implant wear

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. 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 ug, 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 more

than 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 J

ohnson & 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.  

Normal: <1.0 ng/mL

The typical finding in the general population is below the

quantitation limit of this assay, which is 0.1 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.

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 iodide are known to interfere

with most metals tests. If either gadolinium or iodide-containing

contrast media has been administered, a specimen cannot be

collected for 48 hours.

 1.    Tsalev DL, Zaprianov ZK: Biological and toxicological

characteristics of individual elements. Vanadium. In Atomic

Absorption Spectrometry in Occupational and Environmental

Health Practice, Analytical Aspects and Health Significance,

Vol. I. CRC Press, Boca Raton, FL, 1984, pp 204-209

2.       Liu T-K, Liu S-H, Chang C-H, Yang RS: Concentration of metal

elements in the blood and urine in the patients with cementless

total knee arthroplasty.  Tohoku J Exp Med1998;185:253-262

3.       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;21:189-195