Manganese
Summary
Manganese is an essential trace mineral, and deficiency is very rare. No trial has tested it alone: it helped only in combinations, such as calcium plus trace minerals for spinal bone or glucosamine-chondroitin products for knee pain (grade D). The adult upper limit is 11 mg/day, and very high exposure can cause Parkinson-like nerve damage.
Key facts
- An essential trace mineral; the body holds about 10–20 mg, 25%–40% of it in bone[1]
- 2.3 mg/day for men and 1.8 mg/day for women; 2.0 mg in pregnancy and 2.6 mg when breastfeeding[1]
- 11 mg/day for adults from all sources, set to avoid nerve toxicity[1]
- US diets supplied about 2.1–2.8 mg/day in FDA Total Diet Study data, meeting the AI[1]
- Spinal bone density with calcium, zinc and copper (D); knee osteoarthritis symptoms in glucosamine-chondroitin products (D)[2][3][4]
- Multivitamins usually provide 1.0–4.5 mg; single-mineral products mostly 5–20 mg[1]
- None declared in the trial abstracts; the knee trials tested branded glucosamine-chondroitin-manganese products and their funding is not stated in PubMed[3][4]
- 3 graded human outcomes on this page
- October 10, 2026
How it works
EstablishedManganese is a cofactor for enzymes such as manganese superoxide dismutase, arginase and pyruvate carboxylase, which take part in amino acid, cholesterol and glucose metabolism, antioxidant defence and bone formation. Whether extra manganese changes these processes in well-fed people is not established.[1]
What the human research says
Human trials only, one row per outcome. The form column shows what each trial actually tested. Grades follow our evidence-grading policy.
At a glance: strongest evidence per outcome
| Outcome | Grade | Effect | Strongest evidence | Rows |
|---|---|---|---|---|
| Joints | Grade D | Improved | RCT · n = 93 · 2000 | 2 rows |
| Bone | Grade D | Improved | RCT · n = 59 · 1994 | 1 row |
Every graded row
| Outcome | Effect | Grade | Best evidence | PMID |
|---|---|---|---|---|
| Knee osteoarthritis severity (Lequesne index) | Improved | Grade D | RCT · n = 93 · 2000 Adults with knee osteoarthritis (US, single center) Form: Glucosamine HCl 1,000 mg, chondroitin sulfate 800 mg and manganese ascorbate 152 mg (Cosamin DS) · Dose: Twice daily (304 mg/day manganese ascorbate) · Duration: 6 months In mild to moderate osteoarthritis (72 people), severity scores improved versus placebo at 4 and 6 months (response 52% vs 28%); no benefit in severe osteoarthritis. Adverse events 17% vs 19% with placebo. | 10966840 (opens PubMed)Source [3] |
| Spinal bone loss with calcium plus trace minerals | Improved | Grade D | RCT · n = 59 · 1994 Healthy older postmenopausal women (mean age 66) Form: Manganese 5 mg with zinc 15 mg and copper 2.5 mg, with or without calcium citrate malate 1,000 mg · Dose: 5 mg/day of manganese · Duration: 2 years Spinal bone density changed -3.53% with placebo and +1.48% with calcium plus trace minerals, the only significant group difference; trace minerals alone (-1.89%) did not differ from placebo. | 8027856 (opens PubMed)Source [2] |
| Knee and low back pain from degenerative joint disease | Improved | Grade D | Crossover RCT · n = 34 · 1999 US Navy divers and special warfare personnel with chronic knee or low back pain Form: Glucosamine HCl, chondroitin sulfate and manganese ascorbate · Dose: Glucosamine 1,500 mg, chondroitin 1,200 mg and manganese ascorbate 228 mg per day · Duration: 16 weeks (crossover) Knee symptom scores, pain ratings and physical examination scores improved; running times did not change, and the study neither showed nor excluded a benefit for the spine. | 10050562 (opens PubMed)Source [4] |
Forms
| Form | Elemental % | Absorption (human data) | GI tolerance | Studied for |
|---|---|---|---|---|
| Manganese amino acid chelates (bisglycinate, glycinate, aspartate) | Varies[1] | No data on the relative bioavailability of different supplemental forms (ODS).[1] | No form-specific tolerance data in our sources.[1] | Multivitamin and single-mineral supplements |
| Manganese gluconate, sulfate, citrate, chloride or picolinate | Varies[1][6] | Humans absorb about 1%–5% of dietary manganese; absorption rises when iron stores are low.[1][6] | No form-specific tolerance data in our sources.[1] | Multivitamin and single-mineral supplements |
| Manganese ascorbate | Varies[3][4] | No absorption data in our sources.[3] | Adverse events with a glucosamine-chondroitin-manganese ascorbate product were similar to placebo over 6 months.[3][4] | Knee osteoarthritis trials of combination joint products |
Studied doses, daily needs and limits
Doses studied in human trials ranged from 5 mg/day of manganese (with calcium, zinc and copper) for 2 years to 20 mg/day from a controlled diet for 8 weeks. Knee trials used 228–304 mg/day of manganese ascorbate inside glucosamine-chondroitin products; the elemental amount is not given in the abstracts.[2][5][3][4]
Intake reference: Adult Adequate Intake (AI): 2.3 mg/day for men and 1.8 mg/day for women (ages 19+); 2.0 mg/day in pregnancy and 2.6 mg/day when breastfeeding. Adult UL: 11 mg/day from all sources.[1] The UL is based on whole-blood manganese above the normal range and the risk of nerve toxicity. It does not apply to people given manganese under medical supervision. NIH ODS fact sheet (updated March 29, 2021).
Recommended intake and upper limit by age and sex
| Age | Male | Female | Pregnancy | Lactation | Upper limit (UL) |
|---|---|---|---|---|---|
| 0–6 months (AI) | 0.003 mg | 0.003 mg | — | — | Not set |
| 7–12 months (AI) | 0.6 mg | 0.6 mg | — | — | Not set |
| 1–3 years (AI) | 1.2 mg | 1.2 mg | — | — | 2 mg |
| 4–8 years (AI) | 1.5 mg | 1.5 mg | — | — | 3 mg |
| 9–13 years (AI) | 1.9 mg | 1.6 mg | — | — | 6 mg |
| 14–18 years (AI) | 2.2 mg | 1.6 mg | 2 mg | 2.6 mg | 9 mg |
| 19–50 years (AI) | 2.3 mg | 1.8 mg | 2 mg | 2.6 mg | 11 mg |
| 51+ years (AI) | 2.3 mg | 1.8 mg | — | — | 11 mg |
Interactions
Published interactions only: each row cites a source. No row means none was found in our sources, not that a combination is safe.
Who should be careful
- Chronic liver disease
- Manganese leaves the body mainly in bile, so people with chronic liver disease clear it poorly and are more prone to manganese nerve toxicity.[1]
- Long-term intravenous nutrition
- Manganese in long-term parenteral nutrition has caused headache, dizziness and brain MRI changes that resolved after it was stopped.[8]
- High-exposure jobs or well water
- Welders and miners who inhale manganese dust, and people drinking water with very high manganese, have developed nerve toxicity; supplements add to that exposure.[1]
- Infants and children
- For infants, breast milk, formula and food should be the only sources of manganese; children's ULs are 2–9 mg/day depending on age.[1]
Talk to your pharmacist or clinician before starting a supplement, especially if you take prescription medicines.
Safety
Food intakes are safe; problems come from very high exposure.
- Dietary range
- In a controlled feeding study, diets providing 0.8 or 20 mg/day for 8 weeks did not affect neurological measures in healthy young women.[5]
- Nerve toxicity
- Excess manganese mainly affects the nervous system: tremor, muscle spasms, hearing problems and, in time, Parkinson-like gait and balance changes.[1]
- Supplement case
- A 37-year-old woman developed possible Parkinson disease after years of manganese supplement doses well above the upper limit.[7]
- Drug interactions
- The NIH fact sheet lists no clinically relevant interactions with medications.[1]
Food sources
| Food | Serving | Amount |
|---|---|---|
| Mussels, blue, cooked | 3 ounces | 5.8 mg[1] |
| Hazelnuts, dry roasted | 1 ounce | 1.6 mg[1] |
| Pecans, dry roasted | 1 ounce | 1.1 mg[1] |
| Brown rice, medium grain, cooked | 1/2 cup | 1.1 mg[1] |
| Chickpeas, cooked | 1/2 cup | 0.9 mg[1] |
| Spinach, boiled | 1/2 cup | 0.8 mg[1] |
| Tea, black, brewed | 1 cup | 0.5 mg[1] |
- Mussels, blue, cooked5.8 mg
- Hazelnuts, dry roasted1.6 mg
- Pecans, dry roasted1.1 mg
- Brown rice, medium grain, cooked1.1 mg
- Chickpeas, cooked0.9 mg
- Spinach, boiled0.8 mg
- Tea, black, brewed0.5 mg
How to read the label
- Label dose vs clinical doseThe adult AI is 1.8–2.3 mg/day and the bone trial used 5 mg/day; single-mineral products often provide 5–20 mg, up to nearly twice the 11 mg UL.[1][2]
- Elemental amountSupplement Facts labels declare elemental manganese, not the weight of the whole compound.[1]
- Combination joint productsGlucosamine-chondroitin products may list manganese ascorbate; the trials did not test manganese on its own.[3][4]
Cost per studied dose, without the sales pitch
Compare any product you already have by the amount it delivers, not by capsule count or front-of-pack weight.
Cost per studied dose
Enter the price, servings and the amount per serving from your label.
Frequently asked questions
Do most people need a manganese supplement?
Usually not. The NIH says deficiency is very rare, and US diets supply roughly 2.1–2.8 mg/day, at or above the 1.8–2.3 mg AI.[1]
Does manganese help bones?
No trial has tested manganese alone. In a 2-year trial, 5 mg/day with calcium, zinc and copper reduced spinal bone loss compared with placebo.[2][1]
Is manganese in joint supplements useful?
Glucosamine-chondroitin-manganese ascorbate products improved knee symptoms in two small trials, but manganese was not tested separately.[3][4]
What is the upper limit for manganese?
11 mg/day for adults from food, water and supplements combined; 9 mg/day at ages 14–18.[1]
Can too much manganese be harmful?
Yes. High exposure can cause tremor and Parkinson-like symptoms, and one woman developed possible Parkinson disease after years of excessive supplement use.[1][7]
Which foods are high in manganese?
Mussels (5.8 mg per 3 ounces), hazelnuts, pecans, brown rice, chickpeas, spinach and tea.[1]
Sources
- [1]Manganese: Fact Sheet for Health Professionals (updated March 29, 2021). NIH Office of Dietary Supplements, 2021. fact-sheet
- [2]Spinal bone loss in postmenopausal women supplemented with calcium and trace minerals.. J Nutr, 1994. RCT
- [3]Efficacy of a combination of FCHG49 glucosamine hydrochloride, TRH122 low molecular weight sodium chondroitin sulfate and manganese ascorbate in the management of knee osteoarthritis.. Osteoarthritis Cartilage, 2000. RCT
- [4]Glucosamine, chondroitin, and manganese ascorbate for degenerative joint disease of the knee or low back: a randomized, double-blind, placebo-controlled pilot study.. Mil Med, 1999. crossover-RCT
- [5]Dietary manganese intake and type of lipid do not affect clinical or neuropsychological measures in healthy young women.. J Nutr, 2003. PK-study
- [6]Manganese absorption and retention by young women is associated with serum ferritin concentration.. Am J Clin Nutr, 1999. PK-study
- [7]Possible Parkinson's Disease Induced by Chronic Manganese Supplement Ingestion.. Consult Pharm, 2016. observational
- [8]Manganese intoxication during intermittent parenteral nutrition: report of two cases.. JPEN J Parenter Enteral Nutr, 2001. observational
What changed
- First draft. Every PMID checked against NCBI E-utilities esummary (title and year taken from the record) and abstracts read for the cited rows.
- Adversarial review pass: every evidence row re-read against its PubMed abstract. Official sources opened before citing: NIH ODS Manganese fact sheet for health professionals (updated March 29, 2021), whose AI, UL, food, absorption and interaction statements are transcribed here. Industry ties: none declared; the knee trials tested branded combination joint products (Cosamin DS named in the 2000 abstract) and funding for all three trials is not stated in PubMed (no PMC full text). Retraction, expression-of-concern, erratum and withdrawn checks on all 7 PMIDs: none flagged. Page set indexable. Independent browser review (4 parallel reviewers, every evidence row checked against its abstract and official sources on the Vercel preview) found: the 1999 joint trial dose (228 mg/day manganese ascorbate in a 1,500/1,200 mg glucosamine-chondroitin product) and 16-week crossover design were added from the abstract.