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Molybdenum
What is
molybdenum?
Molybdenum is a silverish-white trace element with metallic
properties. It is found most often in soils and is usually
absorbed through the consumption of plant material. The human
body contains about nine milligrams of molybdenum, with the
highest concentrations found in the liver, kidneys, bones
and skin.
Why do
we need it?
Molybdenum is essential for the proper function of certain
enzyme-dependent processes, including the metabolism of iron.
It also forms part of several body enzymes and is needed to
convert a substance called purine into uric acid.
Molybdenum has been used to treat copper toxicity in conditions
such as Wilson's disease. Preliminary evidence has suggested
that molybdenum might prevent certain types of asthma attacks.
It has also been used with fluoride to treat dental decay.
How much
molybdenum should I take?
There is currently no recommended daily allowance (RDA) for
molybdenum. However, the National Academy of Sciences has
deemed the following amounts to be safe and adequate in a
normal diet:
- Adult men: between 75-250 micrograms/day
- Adult women: between 75-250 micrograms/day
- Children aged 7-10: between 50-150 micrograms/day
- Infants: between 15-40 micrograms/day
- Pregnant/lactating women: between 75-250 micrograms/day
What are
some good sources of molybdenum?
Large amounts of molybdenum are found in milk, beans, dark
green leafy vegetables, unrefined cereals and grains. Hard
tap water can also supply molybdenum to the diet.
What can
happen if I don't get enough molybdenum?
Molybdenum deficiency is virtually nonexistent in the U.S.
and is usually seen only in people who have been on prolonged
tube or intravenous feeding or have a genetic inability to
metabolize molybdenum. Symptoms of deficiency include rapid
heartbeat and breathing, headaches, night blindness, anemia,
mental disturbances, nausea and vomiting. Some studies conducted
in Japan and China have linked low levels of molybdenum with
an increased risk of stomach and esophageal cancers.
What can
happen if I take too much?
Molybdenum toxicity is extremely rare in the United States.
Most health experts agree that an intake of as much as 15
milligrams per day is safe; however, large amounts can interfere
with the absorption of copper. In rare cases, excessive molybdenum
consumption can cause nausea, diarrhea, or gout-like symptoms
such as joint pain and swelling.
Other Resources :
The
More You Know About Minerals
The
More You Know About Nutrition
References
• Recommended
Dietary Allowances, 10th ed. Washington, D.C.: National Academy
Press, 1989.
• Johnson JL et al. Molybdenum cofactor deficiency in
a patient previously characterized as deficient in sulfite
oxidase. Biochem Med Metabol Biol 1988;40:8693.
• Turnlund JR, Keyes WR, Peiffer GL. Molybdenum absorption,
excretion, and retention studied with stable isotopes in young
men at five intakes of dietary molybdenum. Am J Clin Nutr
Oct 1995;62:4, p. 790-6.
• Sardesai VM. Molybdenum: an essential trace element.
Nutr Clin Pract Dec 1993;8:6, p. 277-81.
• Nakadaira H, Endoh K, Yamamoto M, Katoh K. Distribution
of selenium and molybdenum and cancer mortality in Niigata,
Japan. Arch Environ Health Sep 1995;50:5, p. 374-80.
• Brewer GJ. Practical recommendations and new therapies
for Wilson's disease. Drugs 1995;50:240-249.
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