Manganese: Everything You Need to Know
Medically reviewed by Suzanne Fisher, MS, RD, LDN
Manganese is an essential mineral found naturally in food and used as a dietary supplement. Most notably, manganese plays a pivotal role in the process of some bodily functions.
For example, some enzymes (proteins) need manganese to work. And through these proteins, manganese affects how the body uses amino acids (building blocks of proteins), cholesterol, glucose (sugar), and carbohydrates.
Manganese is also linked to antioxidant activity, improved bone health, reproductive health, and immune support. And along with vitamin K, manganese can positively improve blood-clotting.
This article will discuss what you should know about manganese—including its potential uses, side effects, interactions, and more.
Explainer
Dietary supplements are not regulated in the same way drugs are in the United States, meaning the Food and Drug Administration (FDA) does not approve them for safety and effectiveness before products are marketed. Choose a supplement tested by a trusted third party, such as the U.S. Pharmacopeia (USP), ConsumerLab.com, or NSF, whenever possible.
However, even supplements that are third-party tested are not necessarily safe for all or effective in general. Therefore, talking to your healthcare provider about any supplements you plan to take and checking in about potential interactions with other supplements or medications is important.
Supplement Facts
Active Ingredient(s): Manganese
Alternate Names(s): Manganese, essential mineral, dietary manganese supplement
Legal Status: Dietary supplement, food, and substances added to food
Suggested Dose: May vary based on age, sex, and medical condition
Safety Considerations: Possible side effects, interactions, and special considerations for children, pregnancy, and breastfeeding
Uses of Manganese
Explainer
Supplement use should be individualized and vetted by a healthcare professional, such as a registered dietitian (RD), pharmacist, or healthcare provider.
No supplement is intended to treat, cure, or prevent disease.
While more extensive research is necessary for quantifying the effectiveness of manganese, people have historically used manganese to treat various health conditions.
Specifically, research is most robust for manganese's effects for the following:
Bone Health
Based on available research, there is a possible link between low manganese levels and females with osteoporosis (weak and brittle bones).
Notably, there are a few long-term studies that demonstrated more bone loss, with participants in the group taking a placebo (a substance with no medicine in it) when compared to the supplement group. The supplement contains manganese, copper, and zinc.
While the results were promising, the supplement contains minerals other than manganese. For this reason, it isn't easy to know manganese's effects. Moreover, some of the studies in the review article are small.
As a result, additional, extensive research with higher quality and larger clinical trials is warranted to understand manganese effects better.
Diabetes
According to results from a large clinical trial in China, there is a U-shaped relationship (first decreasing, then increasing) between manganese levels and type 2 diabetes.
This means that people with low or high manganese levels are more likely to have type 2 diabetes when compared to people with normal manganese levels.
A review article also mentioned animal studies that showed manganese supplementation may improve glucose tolerance. Since there are limited human studies, however, additional research is necessary to study manganese's effects on diabetes in humans.
Manganese Deficiency
While rare, it's possible to have manganese deficiency. For example, you might experience low manganese levels if you consistently don't consume enough for long periods.
What Causes a Manganese Deficiency?
A potential cause of manganese deficiency is not getting enough manganese from foods or supplements. But this is very rare because there are typically plenty of food sources that contain manganese.
How Do I Know If I Have a Manganese Deficiency?
Since manganese deficiency is so rare, more information about low manganese levels in humans needs to be provided.
But, in general, symptoms of manganese deficiency may include:
Abnormal lab values, including calcium, sugar, liver-related labs, etc.
Bone loss
Hair color changes
Low birth weight
Mood changes
More painful premenstrual periods
Rash
Slow growth rate in children
If you suspect that you're experiencing a manganese deficiency or if any of your symptoms feel life-threatening, call 911 and get medical help right away.
What Are the Side Effects of Manganese?
Manganese supplements, as with many medications and natural products, may have side effects.
Common Side Effects
In general, there are no reports of manganese toxicity from the diet. This is because the gut is usually very good at monitoring how much manganese to absorb.
Manganese toxicity, however, may typically occur from sources within your environment—like manganese dust from your workplace or high levels of manganese from your drinking water.
Some possible common side effects of manganese might look similar to Parkinson's disease (PD).
For example, you might experience the following:
Muscle spasms
Tremors
Unsteadiness on your feet
Other side effects may include:
Blood pressure changes
Flushed (red) face, head, and ears
Heart rate changes
Severe Side Effects
Severe side effects are possible, especially with high and toxic doses of manganese.
Examples of severe side effects may include:
Severe allergic reaction: A severe allergic reaction is a profound side effect possible with any medication or natural product. If you're having a severe allergic reaction, symptoms may include breathing difficulties, itchiness, and rash.
Death: A high manganese water level is linked to a higher risk of death in infants, especially within the first year of life.
Low blood pressure: Per a review article, there are reports of hypotension (low blood pressure) with a manganese-containing contrast agent for a magnetic resonance imaging (MRI) scan.
If you're having a severe allergic reaction or if any of your symptoms feel life-threatening, call 911 and get medical help right away.
Precautions
A healthcare provider may advise against manganese supplements if any of the following applies to you:
Severe allergic reaction: Avoid manganese if you have a known allergy to it or its ingredients or parts. If you need clarification on whether it's safe, ask a registered dietitian, pharmacist, or healthcare provider for more information.
Pregnancy: Compared to other essential minerals, there isn't enough evidence for recommended dietary allowances (RDAs) of manganese. Instead, manganese has daily adequate intake (AI) amounts for everyone, including pregnant people.
The AI and upper limit (UL) for pregnant people in the following age groups are:
Between 14 and 18: An AI of 2 milligrams (mg) with a UL of 9 mg without healthcare provider supervision
At least 19: An AI of 2 mg with a UL of 11 mg without healthcare provider supervision
While there are AIs and ULs for manganese, pregnant people tend to have higher manganese levels when compared to the general population. And higher manganese levels may increase the chances of preeclampsia (high blood pressure during pregnancy).
A link exists between high manganese levels in pregnant people and infant brain developmental problems.
Contact a healthcare provider to discuss the benefits, risks, and requirements when pregnant.
Breastfeeding: Instead of RDAs, there are AIs of manganese for breastfeeding parents.
The AI and UL for breastfeeding parents in the following age groups are:
Between 14 and 18: An AI of 2.6 mg with a UL of 9 mg without healthcare provider supervision
At least 19: An AI of 2.6 mg with a UL of 11 mg without healthcare provider supervision
Reach out to a healthcare provider to discuss the benefits, risks, and requirements when breastfeeding.
Adults over age 65: Older adults have participated in some manganese-related studies.
Manganese is also recommended in AIs for people older than 50. For males, the AI is 2.3 mg for this age group. And for females, the AI is 1.8 mg for this age group.
In general, use manganese cautiously. Some older adults may have a higher likelihood of manganese-related side effects, such as PD-like symptoms.
Children: The AIs and ULs of manganese for children of various ages are:
0–6 months: 0.003 mg that is mainly from breastmilk with no established UL from supplements
7–12 months: 0.6 mg with no established UL from supplements
1–3 years: 1.2 mg with a UL of 2 mg
4–8 years: 1.5 mg with a UL of 3 mg, but at age 9, AIs change slightly depending on the child's assigned sex at birth
9–13 years: 1.9 mg for males and 1.6 mg for females—with a UL of 6 mg
14–18 years: 2.2 mg for males and 1.6 mg for females—with a UL of 9 mg
Once you're at least 19 years old, the UL is 11 mg—no matter your sex. This UL only applies if you're taking manganese without supervision from a healthcare provider.
While there are AIs and ULs for manganese, children tend to have high levels of manganese build-up, particularly in their central nervous system (CNS), consisting of the brain and spinal cord).
This is especially the case in 1-year-old infants. For this reason, children are more likely to have brain-related side effects, such as PD-like symptoms.
Also, there is an increased risk of infant death with high manganese levels in the water.
Brain-related conditions: People with brain-related conditions—like PD—might experience worsening symptoms from manganese toxicity-related side effects.
Diabetes; Manganese may improve your glucose tolerance.
For this reason, a healthcare provider may want to monitor you and make necessary medication adjustments closely—especially if you take medications for high blood sugar.
Heart conditions: High amounts of manganese may affect your heart rate and blood pressure.
Thus, a healthcare provider may want to monitor you and make any necessary medication adjustments closely—especially if you take medications for a heart-related condition.
Iron deficiency: If you have low iron levels, your body might absorb more manganese, increasing the risk of manganese-related side effects.
If you have an iron deficiency, healthcare providers may also want to monitor your manganese levels closely.
Liver problems: If you have liver problems, this might increase the likelihood of manganese build-up in the body. And this may raise the chances of manganese-related side effects.
Healthcare providers may want to monitor your manganese levels if you have a liver condition.
Dosage: How Much Manganese Should I Take?
Explainer
Always speak with a healthcare provider before taking a supplement to ensure that the supplement and dosage are appropriate for your individual needs.
AI is the amount of vitamins or minerals assumed to be enough to meet nutritional needs. These AIs may vary based on age, sex, pregnancy, and breastfeeding status.
However, in clinical trials that studied the potential effects of manganese, the strengths of manganese varied.
Also, these clinical trials studied manganese from different sources, such as food and supplements. And some supplements were combination supplements that contain various minerals, including manganese.
As a result, more rigorous research with higher quality and more extensive studies is warranted.
Therefore, no guidelines exist on the appropriate dosage for manganese supplements for any condition.
Follow a healthcare provider's recommendations or product label instructions if you take a manganese supplement.
What Happens If I Take Too Much Manganese?
Toxicity is possible as a result of taking too much manganese.
Generally, the AI of manganese is based on age, sex, pregnancy, and breastfeeding status. This is also the case for manganese's UL.
But once you're older than 18, the UL of manganese is typically 11 mg, the same for everyone. But the UL may vary if you take manganese under a healthcare provider's supervision.
If you accidentally take too much manganese, you may experience overdose symptoms that are likely similar to manganese's potentially common and serious side effects—but they're excessive and severe.
Interactions
Manganese might interact with the following medications:
Diabetes medications: Manganese might improve your glucose tolerance. This may have additive effects with diabetes medications, such as insulin, meaning it can make your diabetes work too well. If your blood sugar is too low, you might experience sweating and tremors.
Heart medications: High amounts of manganese might affect your heart rate and blood pressure. This may interact with your heart medications, such as Toprol (metoprolol) and Zestril (lisinopril).
Parkinson's medications: Side effects of manganese toxicity are similar to PD. Even of you take your PD medications, you may notice worsening symptoms, such as tremors.
It is essential to carefully read a supplement's ingredients list and nutrition facts panel to know which ingredients and how much of each ingredient is included. Please review the supplement label with your healthcare provider to discuss potential interactions with foods, other supplements, and medications.
How to Store Manganese
Storage instructions may vary for different products. Carefully read the directions and packaging label on the container.
Generally, most medicines' optimal storage condition is in a cool and dry place. You should also keep your medications tightly closed and out of the reach of children and pets, ideally locked in a cabinet or closet.
Discard after one year or as indicated on the packaging. Avoid putting unused and expired products down the drain or in the toilet.
Visit the FDA website to learn where and how to discard all unused and expired medications. You may also be able to find disposal boxes in your area.
Ask a pharmacist or healthcare provider any questions you have about how to dispose of your medications or natural products.
If you plan to travel with manganese, get familiar with your final destination's regulations. The U.S. Embassy website might be a helpful resource.
Ask a healthcare provider for advice on traveling with your medications or natural products, if necessary.
Similar Supplements
Manganese may affect osteoporosis (bone health) and diabetes (high blood sugar).
Other potentially similar supplements include:
Chromium: Chromium might improve blood sugar control, but the results are mixed.
Red clover: Study results are inconsistent on red clover being able to improve bone density in people with menopause.
Soy isoflavones: Isoflavones are plant substances that may have estrogen-like effects. Soy contains isoflavone. Soy isoflavone mixture might have some positive postmenopausal effects on bone health. But the results are mixed.
Only combine multiple natural products once you first talk with a healthcare provider, pharmacist, or dietitian. Checking in can help you avoid possible harmful interactions and side effects and ensure you're giving these supplements a fair trial at appropriate doses.
Frequently Asked Questions
What is the most common dosage form of manganese supplements?
Manganese supplements are available in a few different dosage forms—with capsules being the most common.
Does exercise affect manganese levels?
Yes. An overview mentioned one study that showed that aerobic exercise might affect manganese levels. Examples of aerobic exercises are swimming and rowing.
How do I take manganese safely?
To safely take dietary supplements—like manganese—inform your healthcare providers and pharmacists about any medication changes.
This includes over-the-counter (OTC), herbal, natural medicines, and supplements. They can help prevent possible interactions and side effects.
Sources of Manganese & What to Look For
There are several different sources of manganese, but health nutrition guidelines typically place more importance on food sources to improve the diet.
Although food sources are preferable, there might still be a place for supplements for certain groups of people, such as those with certain medical conditions.
Food Sources of Manganese
Manganese is widely available in various foods.
In the United States, the top food sources of manganese are:
Grain products
Tea
Vegetables
Drinking water also contains some manganese.
Manganese Supplements
Manganese supplements are commonly available in capsule form.
Other dosage forms of manganese may also include:
Food bars
Gummies
Liquid
Lozenges
Powder
Tablets
Some of these forms might contain other ingredients.
You may also see vegetarian and vegan options.
What works for you depends on what you like and what you hope to get. Each product may work a bit differently, depending on the form.
Summary
Manganese is an essential mineral found naturally in food but is also available as a dietary supplement.
Aside from a rare manganese deficiency, manganese may have a few potential uses, including bone health and high blood sugar.
Before using manganese, involve a registered dietitian, pharmacist, or healthcare provider to help you safely achieve your health goals.
