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MANFRED ANKE AN. R. ACAD. NAC. FARM.

insulin, but vanadate produces greater simulation of lactate and
glucose oxidation than insulin (26).

In addition to the insulin-mimetic effect of vanadium compounds,
vanadium affects signal transduction mechanisms and proto-onco-
gene expression in vitro (118). At concentrations > 5 mM, orthova-
nadate is cytotoxic to proliferating cells, including primary culture
and tumor cell lines (32, 38).

Vanadyl sulphate with doses up to 60 mg/day is a common sup-
plement used by weight lifters, shot-putters and weight trainers to
improve their performance. A 12 week, double-blind, placebo-con-
trolled clinical trial did not detect any haematological abnormalities
at doses of 0.5 mg vanadyl sulphate/kg day (46).

The Toxicity of Vanadium

Toxicity to Plants

Vanadium phytotoxicity under field conditions is extremely
rare (51). However, under man-induced conditions, vanadium
concentrations as high as 0.5 mg/L in the nutrient solution and
140 mg/kg in the soil solution may be toxic to plants. The phytotoxi-
city of vanadium (chlorosis and dwarfing) may appear at about 2 mg
V/kg dry matter (34).

A vanadium amount of 30 mg/kg soil induced a vanadium con-
centration of 170 µg V/kg dry matter in green oats, of 250 µg/kg in
green mustard and of 700 µg V/kg dry matter in spinach without
signs of intoxication (84).

Toxicity to Animals

For animals, vanadium is a relatively toxic element (89) (Ta-
ble 20). In young cattle, 10 mg V/kg live mass induced diarrhoea and
weakness (99); heifers and cows with high vanadium intake develo-
ped inappetence, black diarrhoea, lethargy, dehydration, spontaneous
abortions and decreased milk production (47).

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