Vanadium [V, 23]
349
plants. The elevated V contents in plants, especially V 5+ species, may inhibit the
function of several enzymes, especially in some legumes.
Plants from industrial regions may contain very high V amounts. Vegetables grown in
the vicinity of a thermal power station contained V within the ranges of 1900– 4900 μg/kg
(cabbage) and 800–1700 μg/kg (tomato) (Belsare vide Kabata-Pendias 2011).
53.6 HUMANS
The total amount of V in the human body is estimated to be about 20 mg, of which
0.02–0.09 μg/L is in the blood, 3 μg/kg in the bone, and 20 mg/kg in the tissues
(Emsley 2011).
Absorption of V from the gastrointestinal tract is poor, not exceeding 2%
(WHO 1988). Its highest concentrations occur in the liver, kidney, and lung. However, it is mainly stored in fat and serum lipids. No biochemical function of V has
been yet defined in humans. Presumable, V plays a role in metabolism of carbohydrates, and also in metabolism of cholesterol and blood lipids. It controls the
biosynthesis of cystine and cholesterol, depression and stimulation of phospholipid synthesis, and, at higher concentrations, inhibition of serotonin oxidation.
In diabetics, V supplement may have a positive effect in regulating blood glucose
levels. Possibly, V prevents heart attack, cataract development, and impaired antioxidant status (ATSDR 2012d). The potential role of V in humans is building
material of bones and teeth, and stimulating muscle development (Badmaev et al.
1999). However, gastrointestinal effects (diarrhea, cramps, nausea, and vomiting)
may occur in non-insulin-dependent diabetic patients, administered vanadyl sulfate or sodium metavanadate capsules, as a supplement to their diabetes treatment
(ATSDR 2012d).
In general, the toxicity of V compounds is low. However, little information is
available regarding the mechanism of V toxicity in vivo. Its pentavalent compounds
and organic forms are safer, more absorbable, and able to deliver a therapeutic effect
up to 50% greater than V inorganic forms.
Workers exposed to V peroxide dust suffer severe eyes, nose, and throat irritation, which have been observed especially in miners of V ores and workers in some
other industries (Halliwell and Gutteridge 2007). It may have a number of effects on
human health, when its uptake is too high. When V uptake takes places through air,
it can cause bronchitis and pneumonia (WHO 1988).
Vanadium pentoxide has important effects on a broad variety of cellular
processes. It stimulates cell differentiation, it causes cell and DNA injury via
generation of reactive oxygen species, and it alters gene expression. It can pass
the blood–placenta barrier. Data on genetic effects in humans exposed to vanadium pentoxide are scarce, and it is classified as possibly carcinogenic to humans
(Group 2B) (IARC 2006, 2013).
Levels of V that are naturally present in food and water (Table 53.2) are not harmful.
Vanadium in food is mainly ingested as VO
2+ (vanadyl,V
4+ ), or HVO
2− (vanadate,V
5+
4
Organic V compounds are used in the treatment of diabetes and cancer. Its intakes, in supplements for individuals with diabetes, are 30–150 mg/day for vanadyl sulfate (9–47 mg
V/day) and 125 mg/day for sodium metavanadate (52 mg V/day) (ATSDR 2012d).
) .
349
plants. The elevated V contents in plants, especially V 5+ species, may inhibit the
function of several enzymes, especially in some legumes.
Plants from industrial regions may contain very high V amounts. Vegetables grown in
the vicinity of a thermal power station contained V within the ranges of 1900– 4900 μg/kg
(cabbage) and 800–1700 μg/kg (tomato) (Belsare vide Kabata-Pendias 2011).
53.6 HUMANS
The total amount of V in the human body is estimated to be about 20 mg, of which
0.02–0.09 μg/L is in the blood, 3 μg/kg in the bone, and 20 mg/kg in the tissues
(Emsley 2011).
Absorption of V from the gastrointestinal tract is poor, not exceeding 2%
(WHO 1988). Its highest concentrations occur in the liver, kidney, and lung. However, it is mainly stored in fat and serum lipids. No biochemical function of V has
been yet defined in humans. Presumable, V plays a role in metabolism of carbohydrates, and also in metabolism of cholesterol and blood lipids. It controls the
biosynthesis of cystine and cholesterol, depression and stimulation of phospholipid synthesis, and, at higher concentrations, inhibition of serotonin oxidation.
In diabetics, V supplement may have a positive effect in regulating blood glucose
levels. Possibly, V prevents heart attack, cataract development, and impaired antioxidant status (ATSDR 2012d). The potential role of V in humans is building
material of bones and teeth, and stimulating muscle development (Badmaev et al.
1999). However, gastrointestinal effects (diarrhea, cramps, nausea, and vomiting)
may occur in non-insulin-dependent diabetic patients, administered vanadyl sulfate or sodium metavanadate capsules, as a supplement to their diabetes treatment
(ATSDR 2012d).
In general, the toxicity of V compounds is low. However, little information is
available regarding the mechanism of V toxicity in vivo. Its pentavalent compounds
and organic forms are safer, more absorbable, and able to deliver a therapeutic effect
up to 50% greater than V inorganic forms.
Workers exposed to V peroxide dust suffer severe eyes, nose, and throat irritation, which have been observed especially in miners of V ores and workers in some
other industries (Halliwell and Gutteridge 2007). It may have a number of effects on
human health, when its uptake is too high. When V uptake takes places through air,
it can cause bronchitis and pneumonia (WHO 1988).
Vanadium pentoxide has important effects on a broad variety of cellular
processes. It stimulates cell differentiation, it causes cell and DNA injury via
generation of reactive oxygen species, and it alters gene expression. It can pass
the blood–placenta barrier. Data on genetic effects in humans exposed to vanadium pentoxide are scarce, and it is classified as possibly carcinogenic to humans
(Group 2B) (IARC 2006, 2013).
Levels of V that are naturally present in food and water (Table 53.2) are not harmful.
Vanadium in food is mainly ingested as VO
2+ (vanadyl,V
4+ ), or HVO
2− (vanadate,V
5+
4
Organic V compounds are used in the treatment of diabetes and cancer. Its intakes, in supplements for individuals with diabetes, are 30–150 mg/day for vanadyl sulfate (9–47 mg
V/day) and 125 mg/day for sodium metavanadate (52 mg V/day) (ATSDR 2012d).
) .