Molybdenum (Mo) is an essential nutrient for animals and humans.
Tissue content of molybdenum is low, with the highest concentrations in
the liver, kidney, adrenal gland and bone. It is a component of a number
of enzymes, including sulfite oxidase (involved in the metabolism of
sulfur amino acids), xanthine oxidase (involved in the oxidation of
purines and pyrimidines and the production of uric acid), and aldehyde
oxidase (involved in the oxidation of aldehydes). These enzymes share a
common "molybdenum cofactor."
Molybdenum deficiency is extremely rare and has only been identified
in the presence of other serious disorders. Metabolic defects in the
molybdenum cofactor are characterized by the absence of the three
molybdoenzymes. Both the deficiency and the metabolic disorders are
accompanied by abnormal excretion of sulfur metabolites, low uric acid
concentrations, and elevated hypoxanthine and xanthine excretion. The
absence of sulfite oxidase in the metabolic disorder leads to death at an
Diet recommendations: The Estimated Safe and Adequate
Dietary Intakes of
molybdenum (µg/day) are: 15-30 at age 0-6 months, 20-40 for 6-12
months, 25-50 for 1-3 years, 30-75 for 4-6 years, 50-150 for 7-10 years,
and 75-250 for adolescents and adults. This range is based on the usual
dietary intake, about 75 to 240 µg/day by adults. The range was
extrapolated for other age groups on the basis of body weight.
Food sources: Rich sources of molybdenum include
legumes, cereal products, and leafy vegetables. The amount in foods
depends on the soil molybdenum content. Molybdenum is very well absorbed,
but its bioavailability may be affected by some food components.
Toxicity: Molybdenum toxicity is much more likely than
deficiency. Toxicity is common in cattle grazing in pastures with high
molybdenum soil. A high incidence of gout has been reported in humans with
intakes of 10-15 mg/day.
Recent research: Controlled studies in humans suggest
molybdenum requirement is well below the usual dietary intake, which
is consistent with lack of molybdenum deficiency in the US population.
Bioavailability studies suggest that molybdenum is less well absorbed from
soy products than from leafy vegetables.