How much manganese per day is safe?

December 7, 2025 •

4 min read

According to the National Institutes of Health, the tolerable upper intake level (UL) for manganese for adults is 11 mg per day. Understanding how much manganese per day is safe is crucial for preventing toxicity, especially from supplements or environmental exposure, and ensuring you meet your body's essential needs from food.

Quick Summary

This guide details the safe daily intake of manganese, covering recommended levels (AI), the tolerable upper limit (UL), and potential risks associated with excessive intake. It addresses how to get enough from food, the dangers of toxicity, and who should be cautious with supplementation.

Key Points

Tolerable Upper Intake Level (UL): For adults 19 and older, the UL for manganese is 11 mg per day from all sources, including supplements.
Dietary Intake is Safest: It is highly unlikely to experience manganese toxicity from food alone, as the body effectively regulates absorption from dietary sources.
Toxicity Risks: The highest risk of manganese toxicity comes from inhaling it in occupational settings like welding or from high-dose supplementation.
Sensitive Individuals: People with chronic liver disease or iron-deficiency anemia should be extra cautious, as their bodies are less efficient at regulating manganese levels.
Supplementation Caution: Most people do not need manganese supplements. If you do consider them, speak with a healthcare provider first, as excessive intake can cause neurological issues.
Role of the Liver: The liver is crucial for controlling manganese levels by excreting excess amounts through bile.

Understanding Manganese

Manganese is an essential trace mineral that the human body requires in small amounts for proper function. It plays a critical role in numerous bodily processes, acting as a cofactor for several important enzymes. Its functions include aiding in the metabolism of carbohydrates, amino acids, and cholesterol, as well as supporting bone formation, reproduction, and the immune system. It is also a key component of the antioxidant enzyme superoxide dismutase (SOD), which helps protect cells from damaging free radicals. Because manganese is needed in trace amounts, most people can get what they need from a balanced diet without needing supplements.

Adequate Intake (AI) Levels by Age and Sex

Since manganese deficiency is very rare, there is no Recommended Dietary Allowance (RDA) for the mineral. Instead, the Food and Nutrition Board at the National Academy of Medicine has established Adequate Intake (AI) levels based on the average daily intake of healthy individuals. These are the amounts considered sufficient to meet the nutritional needs of most people in a healthy population. The recommended intakes vary by age, sex, and life stage, as shown in the table below.

Tolerable Upper Intake Levels (UL) for Manganese

While essential in small doses, excessive manganese can be harmful. The Tolerable Upper Intake Level (UL) is the highest daily intake level likely to pose no risk of adverse health effects for most individuals. Consuming more than the UL, particularly from supplements, increases the risk of toxicity. It's important to remember that these ULs apply to intake from all sources—food, beverages, and supplements.


Life Stage	AI (mg/day)	UL (mg/day)
Infants (0-6 months)	0.003	Not established
Infants (7-12 months)	0.6	Not established
Children (1-3 years)	1.2	2
Children (4-8 years)	1.5	3
Boys (9-13 years)	1.9	6
Girls (9-13 years)	1.6	6
Teen Boys (14-18 years)	2.2	9
Teen Girls (14-18 years)	1.6	9
Adult Men (19+ years)	2.3	11
Adult Women (19+ years)	1.8	11
Pregnant Women	2.0	9 (14-18) / 11 (19+)
Breastfeeding Women	2.6	9 (14-18) / 11 (19+)

Manganese Toxicity: Risks and Symptoms

Manganese toxicity, also known as manganism, primarily affects the central nervous system and is characterized by neurological symptoms similar to Parkinson's disease. While it is extremely rare from dietary sources alone, it can occur from high-dose supplementation or, more commonly, from inhaling manganese dust in occupational settings like welding. Because inhaled manganese bypasses the body's normal regulatory mechanisms, it poses a greater risk.

Symptoms of manganism can develop over months or years and may include:

Psychiatric symptoms like irritability and aggressive behavior
Cognitive deficits affecting memory and concentration
Motor control issues such as tremors, difficulty walking, and muscle spasms
Speech difficulties

Who is at higher risk for toxicity?

Certain individuals are at a higher risk of developing manganese toxicity and should be especially careful with their intake:

Individuals with Liver Disease: The liver is the primary organ for regulating manganese levels, excreting excess amounts through bile. Impaired liver function can lead to manganese accumulation in the body, which can be neurotoxic.
Individuals with Iron-Deficiency Anemia: The transport of manganese is linked to iron status. People with iron deficiency tend to absorb more manganese, increasing their risk of accumulation.

Navigating Manganese from Food vs. Supplements

For most healthy individuals, getting the recommended amount of manganese from a varied diet is sufficient and safe. Rich food sources include:

Whole grains, such as oats, brown rice, and whole-wheat bread
Nuts, including hazelnuts and pecans
Legumes, like chickpeas and lentils
Leafy greens, such as spinach and kale
Seafood, specifically mussels and clams
Certain beverages like tea

Since manganese deficiency is uncommon, supplementation is generally not necessary unless recommended by a healthcare provider. High-dose supplements, particularly when taken long-term or by those in high-risk groups, can increase the chance of reaching toxic levels. It is crucial to follow the guidance of a medical professional before starting any manganese supplementation. The form of manganese in supplements, such as manganese sulfate, may also impact absorption, though more research is needed.

The Body's Balancing Act: How Manganese is Regulated

Systemic regulation of manganese is achieved through a homeostatic process that involves controlling absorption in the intestines and its excretion, primarily through the liver via bile. When intake is low, the body increases absorption; when intake is high, absorption is reduced to prevent accumulation. The liver is central to this process, as it is responsible for the biliary excretion of excess manganese. This is why liver disease poses a significant risk for toxicity, as the body's primary elimination pathway is compromised.

Interactions with other minerals, particularly iron, also play a role in regulation. Iron deficiency can increase manganese absorption, while high iron intake can reduce it. This dynamic is a key consideration for individuals with specific deficiencies or those taking iron supplements.

Conclusion

Manganese is an important trace mineral, and for most healthy adults, a daily intake of 1.8 to 2.3 mg from a balanced diet is adequate. The Tolerable Upper Intake Level (UL) is set at 11 mg per day for adults, a threshold that is typically not exceeded through diet alone. The risk of manganese toxicity, which can lead to serious neurological issues, is most commonly associated with occupational inhalation exposure, but can also occur with excessive supplementation or in individuals with liver disease or iron deficiency. The body has a robust system for regulating manganese levels, primarily involving the liver and controlling intestinal absorption. Therefore, focusing on a nutrient-rich diet with good food sources of manganese is the safest approach for maintaining optimal health, rather than relying on high-dose supplements. Always consult a healthcare provider before taking manganese supplements, especially if you have underlying health conditions.

For more detailed information, consult authoritative sources like the National Institutes of Health (NIH) Office of Dietary Supplements.

Frequently Asked Questions

Excessive manganese intake, especially from inhalation or high-dose supplementation, can lead to toxicity (manganism). Symptoms affect the central nervous system and can include neurological issues like tremors, muscle spasms, and mood changes, often resembling Parkinson's disease.

For most healthy adults, 5mg of manganese is well below the Tolerable Upper Intake Level (UL) of 11mg and is generally considered safe. However, individuals with liver disease or iron-deficiency anemia should be cautious with any supplementation and consult a healthcare provider.

The Adequate Intake (AI) is 2.3 mg per day for adult men and 1.8 mg for adult women. These levels can be easily met through a balanced diet.

It is extremely difficult to consume toxic levels of manganese from food alone. The body has efficient mechanisms to regulate absorption from dietary sources, and excess manganese from food is safely excreted.

The highest risk is for workers who inhale manganese dust or fumes (e.g., welders), people with chronic liver disease that impairs excretion, and those with iron-deficiency anemia who absorb more manganese.

Excellent food sources of manganese include whole grains, nuts (especially hazelnuts and pecans), legumes (chickpeas, lentils), leafy vegetables (spinach, kale), and tea.

Yes, manganese absorption is influenced by other minerals, particularly iron. Iron deficiency can increase manganese absorption. Manganese supplements may also interfere with the absorption of certain antibiotics, and intake should be timed accordingly.