MolybdenumMineral

• Cofactor for four human enzymesLikely helps

  This is the established biochemistry, not a supplement claim. Sulfite oxidase converts sulfite to sulfate, clearing the sulfite generated by methionine and cysteine metabolism and by food preservatives [4].
  
  Xanthine oxidase turns purine breakdown products into uric acid. Aldehyde oxidase and mARC handle drugs, aldehydes, and other toxins [4]. ^[4]

• Molybdenum supplements for esophageal cancer riskNot shown to help

  This was directly tested and did not work. A placebo-controlled trial in Linxian, China gave 30 mcg/day of molybdenum plus 120 mg/day of vitamin C for 5.25 years [4].
  
  There was no reduction in esophageal cancer incidence or mortality [4].
  
  A 25-year follow-up found small increases in death from gastric cardia cancer and from cancer overall in that group. Among participants aged 55 or older at entry, esophageal cancer mortality ran slightly higher (hazard ratio 1.16, 95% CI 1.04–1.30) [4]. ^[4]

• The low-soil-molybdenum cancer correlationPossibly helps

  Linxian, a region of northern China with unusually low soil molybdenum, has esophageal and stomach cancer incidence roughly 10 times the Chinese average and 100 times the US average [4].
  
  Low hair and nail molybdenum has turned up in other high-risk regions too, including parts of northern Iran and South Africa [4]. ^[4]

• Where that correlation collides with the trialPossibly helps

  These two findings point in opposite directions and the Linus Pauling Institute says so plainly [4].
  
  The ecological association links low-molybdenum regions to higher cancer rates. The one interventional trial found no benefit from supplementing, and its long-term follow-up hinted at harm in older participants [4]. ^[4]

• Longevity correlations in two Chinese countiesPossibly helps

  Ecological studies in Rugao and Zhongxiang found correlations between soil, water and rice molybdenum and the share of residents living past 80 to 90 [4].
  
  The researchers themselves flag heavy confounding by other trace elements. Nothing here can be attributed to molybdenum alone [4]. ^[4]

• Extra molybdenum for sulfite sensitivityPossibly helps

  A popular idea with no support in the sources reviewed here. Sulfite oxidase already clears sulfite in anyone with normal molybdenum status, and typical intake sits well above the RDA [1].
  
  No source shows that above-RDA molybdenum improves sulfite tolerance in otherwise healthy people [1][4].
  
  The one condition where molybdenum status genuinely governs sulfite handling is the rare genetic cofactor deficiency, which is managed with targeted replacement therapy instead [4]. ^[1]

• Any disease indicationPossibly helps

  NIH ODS states flatly that molybdenum is not a standard treatment for any disease or disorder [1].
  
  WebMD adds that the FDA has not reviewed molybdenum for safety or effectiveness for any condition [3]. ^[1]

• Dietary deficiency has never been observed in healthy people, and NIH ODS names no population group as being at risk of inadequate intake [1].
• One acquired case exists in the literature, from 1981. A man with Crohn's disease was on long-term total parenteral nutrition that contained no molybdenum [1].
• He developed tachycardia, rapid breathing, headache, night blindness, and eventually coma, alongside biochemical signs of defective uric acid production and sulfur amino acid metabolism [1].
• Everything resolved once his TPN was supplemented with 300 mcg/day of ammonium molybdate [1].
• The other deficiency in the literature is genetic, not dietary. Molybdenum cofactor deficiency disables all four enzymes no matter how much molybdenum the diet supplies [1].^[1]

• Inorganic salts — sodium molybdate, ammonium molybdate, molybdenum chlorideNothing distinguishes them on the evidence.

  Elemental content

  Simple mineral salts, typically supplying 50 to 500 mcg of molybdenum per dose [1]

  Absorption

  No human study has compared the bioavailability of one supplemental form against another.
  
  Both NIH ODS and WebMD say this explicitly, so there is no evidence-based reason to pay more for one salt over another [1][3].

  Best for

  Nothing distinguishes them on the evidence. Pick on price and dose, not on form [1].

• Chelated forms — molybdenum citrate, glycinate, amino acid chelateAnyone who tolerates a chelate better in practice.

  Elemental content

  Molybdenum bound to an organic carrier; the label figure is elemental molybdenum, 50 to 500 mcg per dose [1]

  Absorption

  Chelated minerals are often marketed on superior absorption.
  
  For molybdenum specifically that comparison has never been run in humans [1][3].

  Best for

  Anyone who tolerates a chelate better in practice. There is no measured advantage to point to [1].

• Multivitamin and multi-mineral productsHow most people get any supplemental molybdenum at all.

  Elemental content

  Usually at or below 100% of the 45 mcg/day RDA [6]

  Absorption

  Molybdenum is absorbed unusually efficiently for a trace mineral — roughly 40% to 100% of dietary intake, by passive non-mediated absorption [1].
  
  Infants absorb almost all the molybdenum in breast milk or formula [1].
  
  Soy is the one documented exception, at about 57% to 58% bioavailability [5].

  Best for

  How most people get any supplemental molybdenum at all. Cleveland Clinic advises keeping each nutrient at 100% of its RDA or less [6].

• A neurologic case report at ordinary supplement doses

  This is the most alarming report in the literature and it happened inside the UL, not far above it.
  
  An adult man took a molybdenum supplement totalling 13.5 mg over 18 days, roughly 300 to 800 mcg/day [4].
  
  He developed acute psychosis, hallucinations, seizures, and other neurologic symptoms [4][5]. It is a single case report, not a dose-response finding. ^[4]

• Gout-like symptoms at very high dietary intake

  An Armenian population eating food grown in extremely high-molybdenum soil took in an estimated 10 to 15 mg/day, five to seven times the adult UL [1].
  
  They developed achy joints, gout-like symptoms, and abnormally high blood uric acid [1].
  
  The mechanism is molybdenum-dependent xanthine oxidase running harder, since that enzyme is what produces uric acid [4]. ^[1]

• Acetaminophen, in rats only

  High-dose molybdenum inhibited the sulfation of acetaminophen in rats [4].
  
  Whether this happens at molybdenum doses humans actually take is not known [4]. ^[4]

• Bone mineral density in older women

  An observational study of 1,496 people found higher molybdenum intake associated with lower lumbar spine bone mineral density in women over 50 [5].
  
  Animal work points the same way: decreased bone growth in molybdenum-fed rats, foot-bone damage in ducks [5]. Observational plus animal data is a signal, not a conclusion. ^[5]

• Sperm quality and testosterone in men

  Observational studies in men recruited from fertility clinics found higher blood molybdenum associated with lower sperm count and quality [5].
  
  Combined with low zinc, it was associated with a 37% reduction in testosterone [5]. The researchers state more research is needed on both. ^[5]

• Occupational exposure

  Acute molybdenum toxicity is rare in the general population and shows up mostly at work — mining, metalworking, molybdenite roasting [4].
  
  Exposed workers have shown elevated serum uric acid and ceruloplasmin [4]. ^[4]

• Copper — the sources genuinely disagree

  In ruminant livestock the effect is settled: high dietary molybdenum plus sulfur forms thiomolybdates in the gut that bind copper and block absorption, causing fatal copper-deficiency disease [4].
  
  In humans it is unsettled. An early study found intakes of 500 and 1,500 mcg/day from sorghum raised urinary copper excretion [4].
  
  A more recent, better-controlled study found intakes up to 1,500 mcg/day did not harm copper status in eight healthy young men [4].
  
  Despite that, Cleveland Clinic's Melissa Young still cautions that too much supplemental molybdenum may lead to copper deficiency in practice [6].
  
  We are flagging the disagreement rather than picking a winner. ^[4]

• Prescription medications generally

  NIH ODS states that molybdenum has no known, clinically relevant interactions with medications [1].
  
  WebMD reports the same, while noting that drug-interaction research on molybdenum is incomplete [3]. Absence of documented interactions is not the same as a clean bill. ^[1]

• Tetrathiomolybdate is a drug, not this

  Tetrathiomolybdate forms high-affinity complexes with copper and is used pharmacologically in Wilson's disease, a genetic disorder of toxic copper accumulation [4].
  
  It has also been explored in early trials for certain cancers and inflammatory conditions [4].
  
  This is targeted molybdenum chemistry given as a drug. It says nothing about ordinary dietary or supplemental molybdenum. ^[4]

Legumes lead, comfortably. Whole grains, nuts, and beef liver follow, and across US diets overall the top contributors are legumes, cereal grains, leafy vegetables, beef liver, and milk [1].

For children and teens, milk and cheese are the main sources [1].

The standout in NIH's USDA-derived table is black-eyed peas, at 288 mcg per half cup boiled — 640% of the Daily Value [1]. Pan-fried beef liver and boiled lima beans tie at 104 mcg per serving (231% DV) [1].

Mid-range: plain low-fat yogurt 26 mcg/cup (58% DV), 2% milk 22 mcg/cup (49% DV), a medium baked potato 16 mcg (36% DV), Cheerios or shredded wheat 15 mcg per half cup (33% DV) [1].

Also a medium banana 15 mcg (33% DV), cooked white rice 13 mcg per half cup (29% DV), whole wheat bread 12 mcg/slice (27% DV), and dry-roasted peanuts 11 mcg/oz (24% DV) [1].

Most fruits and many vegetables are low. An orange has 4 mcg, and raw carrots or boiled green beans only 2 to 3 mcg per serving [1].

Two caveats. Content swings with the soil and irrigation water the food grew in, which is why USDA FoodData Central lists no molybdenum values at all [1].

Drinking water is a minor source at about 3 mcg/day, though a 2017 EPA survey found 0.8% of US samples above 40 mcg/L [1].

Absorption from food is high, roughly 40% to 100%, with soy the exception at 57% to 58% [1][5].

For context on whether any of this needs topping up: the 1984 FDA Total Diet Study put average intake at 109 mcg/day in men and 76 mcg/day in women, against a 45 mcg/day RDA [1]. Among NHANES III supplement users, supplements added roughly 23 to 24 mcg/day on top [1].

No source reviewed here establishes a best time of day, or a fed versus fasted preference, for molybdenum [1][3].

WebMD's guidance is generic — follow the product label or a healthcare provider's instructions [3].

There is a reason the question was never studied. Cleveland Clinic, the Linus Pauling Institute, and Healthline all note that supplementation is unnecessary for healthy people whose diets already exceed the RDA [4][5][6].