Some links on this site are paid links: if you buy through them, we earn a commission at no extra cost to you. This page has no paid links. Affiliate disclosure.
The tolerable upper intake level (UL), or upper limit, for molybdenum is 2,000 mcg a day for adults 19 and older. That is the most a day that is unlikely to cause harm for almost everyone; above it, the chance of side effects goes up. It is a ceiling, not a target. The limit counts molybdenum from food, water and supplements together.
Check your amount
Servings a day
This limit is the same for adults 19 and older, including pregnancy and breastfeeding.
Type the amount from your label to compare it with the upper limit.
Take more than one supplement? Add them all up in the Supplement Checker.
Molybdenum upper limits by age
| Age | Males | Females | Pregnancy | Breastfeeding |
|---|---|---|---|---|
| Birth to 6 months | Not set | Not set | – | – |
| 7-12 months | Not set | Not set | – | – |
| 1-3 years | 300 mcg | 300 mcg | – | – |
| 4-8 years | 600 mcg | 600 mcg | – | – |
| 9-13 years | 1,100 mcg | 1,100 mcg | – | – |
| 14-18 years | 1,700 mcg | 1,700 mcg | 1,700 mcg | 1,700 mcg |
| 19-30 years | 2,000 mcg | 2,000 mcg | 2,000 mcg | 2,000 mcg |
| 31-50 years | 2,000 mcg | 2,000 mcg | 2,000 mcg | 2,000 mcg |
| 51-70 years | 2,000 mcg | 2,000 mcg | – | – |
| 71+ years | 2,000 mcg | 2,000 mcg | – | – |
No upper limit could be set for babies; the National Academies say their intake should come from food and formula only.
How much Molybdenum you need
| Age | Males | Females | Pregnancy | Breastfeeding |
|---|---|---|---|---|
| Birth to 6 months | 2 mcg* | 2 mcg* | – | – |
| 7-12 months | 3 mcg* | 3 mcg* | – | – |
| 1-3 years | 17 mcg | 17 mcg | – | – |
| 4-8 years | 22 mcg | 22 mcg | – | – |
| 9-13 years | 34 mcg | 34 mcg | – | – |
| 14-18 years | 43 mcg | 43 mcg | 50 mcg | 50 mcg |
| 19-30 years | 45 mcg | 45 mcg | 50 mcg | 50 mcg |
| 31-50 years | 45 mcg | 45 mcg | 50 mcg | 50 mcg |
| 51-70 years | 45 mcg | 45 mcg | – | – |
| 71+ years | 45 mcg | 45 mcg | – | – |
* Adequate Intake (AI): the amount set when there isn’t enough evidence for an RDA.
What counts toward the Molybdenum limit
The limit counts molybdenum from food, water and supplements together.
The adult limit of 2,000 mcg is 2 mg.
What happens with too much Molybdenum
The National Academies based the adult UL of 2 mg a day on animal data: finding too little evidence to link excess molybdenum to any harm in healthy people, the report says "reproductive effects in rats were selected as the most definitive toxicological indices," using a study of female rats (Fungwe and coworkers, 1990) in which higher doses were linked to a prolonged estrus cycle and "several adverse effects on embryogenesis." The rats' no-observed-adverse-effect level (0.9 mg per kg of body weight a day) was divided by an uncertainty factor of 30 to reach the human value. In people, the report mentions a 1961 study that observed high blood uric acid and joint pain (hyperuricemia and arthralgias) in Armenians eating 10 to 15 mg of molybdenum a day from food, but it notes serious methodological problems with that study.
Sources: National Academies, Dietary Reference Intakes for Vitamin A, Vitamin K, Arsenic, Boron, Chromium, Copper, Iodine, Iron, Manganese, Molybdenum, Nickel, Silicon, Vanadium, and Zinc (2001); Health Canada, Dietary Reference Intakes tables (the joint U.S.-Canada values). Limits checked November 8, 2026. More from the NIH: Office of Dietary Supplements Molybdenum fact sheet.
If you think you or a child took too much of a supplement, call Poison Control at 1-800-222-1222 (U.S., free, 24 hours) or use poison.org. In an emergency, call 911.
General information, not medical advice. Your doctor may recommend a different amount, for example to treat a deficiency. Talk to your doctor or pharmacist before you start, stop or change a supplement, especially if you are pregnant, nursing, take medication or have a medical condition.