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Manganese: What the Research Shows
Manganese is an essential trace mineral required for numerous biological processes, including bone formation, blood clotting, and cellular metabolism. It serves as a vital cofactor for several enzymes, most notably the antioxidant superoxide dismutase.
Last updated 7 October 2026
Manganese: the short answer
Manganese is an essential trace mineral, but deficiency is very rare and most people get enough from food. There is little human evidence that supplements help: no trial has tested manganese alone for bone health, and human trials on blood sugar are lacking. Too much manganese can harm the nervous system.
| What it is | An essential trace mineral that acts as a cofactor for enzymes such as manganese superoxide dismutase (MnSOD), arginase and pyruvate carboxylase. Found in whole grains, shellfish, nuts, legumes, leafy vegetables and tea; humans absorb only about 1% to 5% of dietary manganese. |
|---|---|
| Most studied for | Bone density (only as part of mineral combinations with calcium, zinc and copper) and blood sugar or type 2 diabetes (mostly observational and animal studies). |
| Amounts used in studies | One 2-year trial in 59 postmenopausal women gave 5 mg manganese a day with 15 mg zinc, 2.5 mg copper and 1,000 mg calcium. A 124-day study in 47 women used 15 mg a day (above the upper limit) to track manganese status. The adult Adequate Intake is 2.3 mg a day for men and 1.8 mg for women. |
| Strength of evidence | Limited. No trials have tested manganese alone for any health outcome; the bone trial used a mineral mix, and diabetes evidence is mixed observational data plus animal research. |
| Safety | The adult upper limit is 11 mg a day. Excess, mainly from inhaled dust at work or drinking water very high in manganese, can cause manganism with tremor, muscle spasms and Parkinson-like problems with gait and balance. People with chronic liver disease or iron deficiency are more susceptible. NIH ODS lists no clinically relevant drug interactions. |
| In products we review | GlucoTrust, Thyrafemme Balance, NeuroZoom |
Sources: NIH ODS manganese fact sheet · Strause 1994 bone trial, J Nutr · Davis & Greger 1992 MnSOD study
Benefits of Manganese
What is Manganese?
Manganese is a trace mineral that the human body requires in small amounts for various physiological functions. While it is often overshadowed by minerals like calcium or iron, it is no less critical to human health. Manganese is not found as a free element in nature; it is often found in combination with iron and other minerals. In the human body, it is primarily stored in the bones, liver, pancreas, and kidneys, where it facilitates a wide range of chemical reactions.
Origins and Discovery
The name manganese comes from the Latin word 'magnes,' meaning magnet, due to its confusion with magnetic ores in ancient times. It was first isolated as a distinct element in 1774 by the Swedish chemist Johan Gottlieb Gahn. However, it wasn't until the early 20th century that scientists began to understand its nutritional importance. In 1931, researchers discovered that manganese was essential for growth and reproduction in animals, leading to its eventual classification as an essential nutrient for humans. Today, most people get it from foods such as whole grains, legumes, nuts, shellfish, leafy green vegetables and tea, and it is included in many, but not all, multivitamin/mineral supplements.
Top Rated Supplements with Manganese
Products we review that list Manganese as an ingredient. Not every product discloses how much of each ingredient a serving contains, so check each review before assuming it matches the amounts used in studies.
GlucoTrust is a dietary supplement marketed to support healthy blood sugar levels and sleep quality, using a blend of herbs, a vitamin and minerals. It is aimed at people who want to add a supplement to diet and exercise, and its marketing links sleep to blood sugar, although none of its listed ingredients has been studied as a sleep aid. While not a replacement for medical treatment, it offers a lifestyle-oriented approach to wellness.
Thyrafemme Balance is a 14-ingredient capsule sold to women for “thyroid balance”, with energy, mood, weight, hair and skin among the promised benefits. This review covers the full label, what research shows for selenium, ashwagandha and iodine, why women with thyroid disease or on thyroid medicine should be careful, the real prices and the 60-day refund.
NeuroZoom is a dietary supplement that the vendor markets for memory, focus and mental clarity. The vendor calls it a 35-in-1 formula of vitamins, minerals, plant extracts and other compounds, but does not publish the amount of each. It is primarily intended for individuals looking to maintain their cognitive edge as they age or those facing high-pressure mental environments. Only a few of its ingredients, such as bacopa, have trial evidence for memory, and the formula itself has not been tested in a published trial.
Scientific Analysis of Manganese
Mechanism of Action: How Manganese Works in the Body
Manganese functions primarily as an enzymatic cofactor or as a constituent of metalloenzymes. This means it acts as a 'helper molecule' that triggers or accelerates chemical reactions necessary for life. One of its most critical roles is as a component of the enzyme manganese superoxide dismutase (MnSOD). MnSOD is the main superoxide-clearing enzyme inside mitochondria, the parts of cells that produce energy. It neutralizes superoxide radicals, which are toxic byproducts of energy production, thereby protecting cells from oxidative stress and DNA damage.
Beyond its antioxidant role, manganese is vital for the metabolism of macronutrients. It activates enzymes involved in the metabolism of carbohydrates, amino acids, and cholesterol. For instance, it is a cofactor for the enzyme pyruvate carboxylase, which is essential for gluconeogenesis—the process by which the body creates glucose from non-carbohydrate sources. Furthermore, it plays a role in the urea cycle, helping the body detoxify ammonia, a byproduct of protein breakdown.
Health Benefits and What the Research Shows
Bone Health
Manganese is a cofactor for several enzymes involved in bone formation. No clinical trials have tested manganese alone for bone health; the only trial evidence comes from a mineral combination given to postmenopausal women. A small 2-year trial in 59 postmenopausal women, published in the Journal of Nutrition, found less spinal bone loss with calcium plus zinc, manganese and copper than with placebo, but showed no clear difference from calcium alone. Because manganese was given with other minerals, the trial cannot show what manganese itself contributed.
Metabolic Health and Blood Sugar Regulation
Manganese plays a complex role in glucose metabolism. The pancreas contains manganese, and animal research suggests manganese may affect glucose tolerance. Observational studies are mixed: some link lower blood manganese to type 2 diabetes, others link higher levels to it, and one large study found a U-shaped pattern. Human trials of manganese supplements for blood sugar are lacking, so it is not known whether supplements help prevent or manage diabetes.
Wound Healing and Collagen Production
Manganese is sometimes promoted for wound healing, based on its role in enzymes rather than on human trials. Manganese is required for the activation of prolidase, an enzyme that provides the amino acid proline for collagen formation in human skin cells. Collagen is the structural protein that provides strength and elasticity to the skin and connective tissues. Whether low manganese intake slows wound healing in people has not been established.
Manganese and the Brain
The brain requires manganese for several functions, including the synthesis of neurotransmitters and the protection of neurons from oxidative damage. Manganese is a cofactor for glutamine synthetase, which converts the excitatory neurotransmitter glutamate into glutamine. This regulation is crucial because an excess of glutamate can lead to excitotoxicity, a condition where nerve cells are damaged or killed by overstimulation. However, the relationship between manganese and the brain is delicate, as both deficiency and excess can lead to neurological issues.
Safety, Side Effects, and Toxicity
While manganese is essential, it is a mineral where 'more' is not necessarily 'better.' The human body has efficient homeostatic mechanisms to regulate manganese levels, primarily through biliary excretion. However, excess exposure, mainly from breathing manganese dust at work or drinking water very high in manganese, can cause a toxic condition called manganism. Symptoms of manganism resemble Parkinson's disease, including tremors, difficulty walking, and facial muscle spasms.
For the general population, the Tolerable Upper Intake Level (UL) for manganese is set at 11 mg per day for adults. There is no RDA; the Adequate Intake (AI) for adults is 1.8 to 2.3 mg a day, which most people get from food. Side effects at usual supplement doses have not been well studied. Individuals with chronic liver disease should exercise caution, as the liver is the primary organ responsible for clearing excess manganese from the body.
Frequently Asked Questions
There is no RDA for manganese; the Adequate Intake (AI) is 2.3 mg a day for adult men and 1.8 mg for adult women. Pregnant and lactating women may require slightly more, approximately 2.0 to 2.6 mg per day.
Yes, most people can meet their manganese needs through a diet rich in whole grains, nuts (like hazelnuts and pecans), legumes, spinach, and tea. The NIH Office of Dietary Supplements notes no known groups of people likely to have inadequate intakes, so supplements are rarely needed.
According to the NIH Office of Dietary Supplements, manganese is not known to have clinically relevant interactions with medications. Claims that it reduces absorption of quinolone or tetracycline antibiotics are not well documented; ask a pharmacist if you take these drugs. Iron status does matter: higher iron intake is linked with lower manganese absorption, and iron deficiency increases it.
There is little research on the best time to take manganese; most people get it from food or a multivitamin. It is often included in multi-mineral or bone-support formulas.
⚖️ Conclusion
Manganese is an essential trace mineral that acts as a cofactor for several enzymes. It is part of the antioxidant enzyme MnSOD and supports enzymes involved in bone formation, but there is no evidence that extra manganese from supplements improves health through these roles. Evidence for bone health comes from one small trial of a calcium and trace mineral mix, so manganese's own effect is unknown. Its role in glucose metabolism has not been shown to translate into benefits from supplements, and too much manganese can harm the nervous system. Deficiency is very rare in humans, and most people get enough manganese from food. Adults should stay below the upper limit of 11 mg a day from all sources and avoid high-dose supplements unless a healthcare professional advises them. For most people, a balanced diet provides enough manganese, and there is no evidence that extra amounts improve health. Manganese supplements have not been shown to improve bone strength or other health outcomes in people who already get enough.