Molybdenum

What it is

Molybdenum is an essential trace mineral found naturally in many foods and sold as a supplement. In the body it works as part of a cofactor (molybdopterin) that four enzymes need, including sulfite oxidase and xanthine oxidase.

What the research says

Molybdenum is needed for a small set of enzymes, and dietary deficiency has never been seen in healthy people; the only acquired deficiency on record was a patient fed intravenously without it. The largest randomised trial that included molybdenum (with vitamin C) in rural China showed no effect on total mortality over 25 years. Excess is uncommon from food, but one man developed psychosis and seizures after 18 days of supplement use.

Evidence grade: Limited evidence.

What goes wrong

A man taking a molybdenum supplement developed acute psychosis, seizures and lasting brain damage; this is a single case report, the first of its kind. (Source 1)

• Case report, Very low certainty.
• Size: 1 patient.
• Who: Male in his late thirties.
• How long: 18 days.
• Result: Cumulative 13.5 mg (300-800 µg/day); psychosis, petit mal and grand mal seizures; toxic encephalopathy one year later.
• Funding: Not stated.

In over 18 days, the patient had consumed a cumulative dose of 13.5 mg Mo (300-800 µg Mo/day).

Gout-like symptoms were reported in an Armenian population with very high molybdenum intake from food. (Source 2)

• Survey study, Very low certainty.
• Size: Not stated in fetched text.
• Who: Population in Armenia.
• How long: Habitual intake.
• Result: 10-15 mg molybdenum per day from food.
• Funding: Not stated.

Gout-like symptoms have also been reported in an Armenian population consuming 10 to 15 milligrams (mg) of molybdenum from food daily.

High-dose molybdenum inhibited acetaminophen metabolism in rats; whether this happens in humans at usual doses is unknown. (Source 2)

• Animal study, Very low certainty.
• Size: Not stated.
• Who: Rats.
• How long: Not stated.
• Result: Inhibition of acetaminophen metabolism.
• Funding: Not stated.

High doses of molybdenum have been found to inhibit the metabolism of acetaminophen in rats; however, it is not known whether this occurs at clinically relevant doses in humans.

What the evidence supports

The only documented acquired molybdenum deficiency occurred in a Crohn's disease patient on long-term intravenous feeding without molybdenum, showing the mineral is required in humans. (Source 2)

• Case report, Very low certainty.
• Size: 1 patient.
• Who: Adult with Crohn's disease on total parenteral nutrition.
• How long: Long-term TPN.
• Result: Rapid heart and breathing rates, headaches, night blindness, coma.
• Funding: Not applicable.

The only documented case of acquired molybdenum deficiency occurred in a patient with Crohn's disease on long-term total parenteral nutrition (TPN) without molybdenum added to the TPN solution.

What the evidence does not support

A large factorial randomised trial giving vitamin C plus molybdenum (Factor C) among other combinations found no effect of any intervention on total mortality through 25 years of follow-up. (Source 3)

• Randomized trial, Moderate certainty.
• Size: 29,584 residents.
• Who: Adults aged 40-69 in Linxian, China, a nutritionally deprived population.
• How long: 5.25 years of supplementation, 25 years of follow-up.
• Result: No effect on total mortality for any factor through 2016.
• Funding: Not stated in fetched text (US National Cancer Institute collaboration)

Through 2016, the interventions showed no effect on total mortality.

Where the evidence is mixed

In the same trial, starting before age 55 was linked to fewer non-upper gastrointestinal cancer deaths for Factor A (retinol/zinc) and fewer stroke deaths for Factor C (vitamin C/molybdenum), while starting after age 55 was linked to more oesophageal cancer for Factors C and D; these are subgroup results for combinations, not molybdenum alone. (Source 3)

• Randomized trial, Low certainty.
• Size: 29,584 residents.
• Who: Adults aged 40-69 in Linxian, China.
• How long: 5.25 years supplementation, 25 years follow-up.
• Result: Under 55: non-upper GI cancer death, Factor A HR = 0.80 (95% CI 0.69 to 0.92); stroke death, Factor C HR = 0.89 (95% CI 0.82 to 0.96). Intervention started after 55: oesophageal cancer, Factor C HR = 1.16 (95% CI 1.04 to 1.30) and Factor D HR = 1.20 (95% CI 1.07 to 1.34)
• Funding: Not stated in fetched text.

Protective effects were found in people younger than age 55 years at baseline against non-upper gastrointestinal cancer death for Factor A (HR = 0.80, 95% CI = 0.69 to 0.92) and against death from stroke for Factor C (HR = 0.89, 95% CI = 0.82 to 0.96). In contrast, increased risk of esophageal cancer was found when the intervention began after age 55 years for Factors C (HR = 1.16, 95% CI = 1.04 to 1.30) and D (HR = 1.20, 95% CI = 1.07 to 1.34).

Position (NIH ODS): molybdenum has no known clinically relevant interactions with medications. (Source 4)

• Official position, Certainty not rated.
• Size: Not applicable.
• Who: Not applicable.
• How long: Not applicable.
• Result: Not applicable.
• Funding: Government.

Molybdenum has no known, clinically relevant, interactions with medications.

How much

• Reference intake: RDA 45 mcg/day for adults, set by the Food and Nutrition Board of the Institute of Medicine in 2001 (per NIH ODS and LPI). (Source 2)
• Upper limit: UL 2,000 mcg/day for adults 19+ (Institute of Medicine, 2001, as reported by NIH ODS). (Source 4)
• Studied: The Linxian trial gave vitamin C plus molybdenum daily for 5.25 years as one factor of a factorial design. (Source 3)
• Studied: The toxicity case took 300-800 µg/day from a supplement for 18 days (13.5 mg cumulative). (Source 1)

A common belief, and what the research shows

The belief: More molybdenum from supplements is harmless because the body excretes it.

What the research shows: Food sources are rarely a problem, but a supplement case report describes 'acute psychosis with visual and auditory hallucinations, a series of petit mal seizures, and one life threatening grand mal attack' after 300-800 µg/day for 18 days.

Questions and answers

What is it?

Molybdenum is an essential trace mineral found in many foods and in supplements. The body uses it inside a cofactor called molybdopterin. (Source 4)

What does it do in the body?

It lets four enzymes work, including sulfite oxidase (which clears sulfite) and xanthine oxidase. If the cofactor cannot be made, all of these enzymes fail together. (Source 2)

Is it good or bad for you?

It is essential in small amounts and deficiency from diet is unknown in healthy people. Toxicity appears low, but one supplement user developed psychosis and seizures, and very high food intake has been tied to gout-like symptoms. (Source 2)

How do you get more of it?

In studies, intake comes mostly from food, especially legumes; supplements are also available. No trial shows extra molybdenum benefits people who already eat a normal diet. (Source 4)

If it is harmful, what reduces it?

In healthy people the kidneys clear excess quickly. In the one supplement poisoning case, symptoms eased within hours of chelation therapy with CaEDTA given by doctors. (Source 1)

Why might someone be low in it or missing it?

Dietary deficiency has not been seen in healthy people. The known causes are a rare inherited defect in making the cofactor, and one case of long-term intravenous feeding without molybdenum. (Source 4)

Which whole foods contain it or feed it?

Beans, lentils and peas are the richest sources; grains and nuts are good sources. Animal foods, fruit and many vegetables are low. (Source 2)

What happens if you do not have it?

In the one documented acquired case, the patient developed a fast heart rate and breathing, headaches, night blindness and eventually coma. The inherited cofactor defect disrupts all molybdenum enzymes. (Source 2)

How can you test for it?

Molybdenum status is not measured in routine clinical care because deficiency is so rare. No validated routine blood test for status was described in the sources we read. (Source 4)

References

1. Arhiv za higijenu rada i toksikologiju. A case report of acute human molybdenum toxicity from a dietary molybdenum supplement--a new member of the "Lucor metallicum" family. 1999. PMID 10649845. Read the source
2. Linus Pauling Institute, Oregon State University. Molybdenum (Micronutrient Information Center). 2021. Read the source
3. Journal of the National Cancer Institute. Effects of Nutrition Intervention on Total and Cancer Mortality: 25-Year Post-trial Follow-up of the 5.25-Year Linxian Nutrition Intervention Trial. 2018. PMID 29617851, DOI 10.1093/jnci/djy043. Read the source
4. NIH Office of Dietary Supplements. Molybdenum - Health Professional Fact Sheet. 2021. Read the source