Manganese
Also known as: Mn
What Does Manganese Measure?
Manganese (Mn) is a trace mineral found in the blood that reflects the body's levels of this essential micronutrient. A blood manganese test measures the concentration of manganese in whole blood or serum, providing insight into both nutritional status and potential toxic exposure. Manganese is stored primarily in the liver, kidneys, pancreas, and bones, but blood levels serve as a useful indicator of recent intake or exposure.
Why Does Manganese Matter?
Manganese is a cofactor for numerous enzymes involved in bone formation, amino acid metabolism, glucose regulation, and antioxidant defense (as part of manganese superoxide dismutase, or MnSOD). It plays a critical role in neurological function, immune response, and the metabolism of carbohydrates and cholesterol. While manganese deficiency is rare in healthy adults, excess manganese — particularly from occupational or environmental exposure — is neurotoxic and can cause a Parkinson's-like condition called manganism. Monitoring manganese levels is therefore important for both nutritional adequacy and safety in at-risk populations.
Normal Ranges
Males
4–15 µg/L (whole blood); 0.4–1.0 µg/L (serum)
Females
4–15 µg/L (whole blood); 0.4–1.0 µg/L (serum)
Children
Varies by age; generally 5–15 µg/L (whole blood)
Causes of High Levels
- Occupational exposure to manganese dust or fumes (e.g., welding, mining, steel manufacturing)
- Liver disease or cirrhosis, which impairs biliary excretion of manganese
- Prolonged total parenteral nutrition (TPN) containing manganese supplements
- Excessive dietary supplementation with manganese or manganese-containing products
- Environmental contamination of drinking water with high manganese levels
- Neonatal or infant exposure through manganese-fortified formulas
Causes of Low Levels
- Inadequate dietary intake of manganese-rich foods over prolonged periods
- Malabsorption syndromes such as Crohn's disease or celiac disease
- High intake of calcium, iron, or magnesium, which compete with manganese absorption
How to Improve Your Manganese
Diet
- Increase intake of whole grains such as oats, brown rice, and wheat germ, which are among the richest dietary sources of manganese
- Consume legumes regularly, including chickpeas, lentils, and black beans, which provide significant manganese
- Eat leafy green vegetables such as spinach and kale, as well as pineapple and berries, which contain appreciable amounts of manganese
- Include nuts and seeds (hazelnuts, pecans, pumpkin seeds) as snacks or meal additions to boost manganese intake
- Limit high-dose calcium or iron supplements taken alongside meals, as these can inhibit manganese absorption
Supplements
- Manganese gluconate or manganese sulfate: 2–5 mg/day for deficiency (do not exceed the tolerable upper intake level of 11 mg/day for adults)
- Multivitamin/mineral complexes containing 2–3 mg of manganese as part of a balanced micronutrient regimen
- Avoid standalone high-dose manganese supplements unless directed by a healthcare provider due to neurotoxicity risk
Related Biomarkers
Frequently Asked Questions
What are the symptoms of manganese toxicity?
Manganese toxicity, known as manganism, primarily affects the nervous system and can mimic early Parkinson's disease. Symptoms include tremors, muscle stiffness, slowed movement, mood changes (irritability, anxiety, hallucinations), and cognitive impairment. These symptoms are most commonly seen in workers with chronic occupational exposure to manganese dust or fumes, or in patients receiving long-term parenteral nutrition with excessive manganese content.
Is manganese deficiency common?
True manganese deficiency is rare in people eating a varied diet, because manganese is widely distributed in plant-based foods like whole grains, nuts, and legumes. However, subclinical low intake can occur in individuals with very restrictive diets, malabsorption disorders, or those consuming large amounts of foods or supplements that interfere with manganese absorption, such as high-dose calcium or iron.
Can drinking water be a source of excess manganese?
Yes, drinking water — particularly from well or groundwater sources — can contain elevated levels of manganese due to natural geological deposits or industrial contamination. The WHO guideline for manganese in drinking water is 0.08 mg/L, and the U.S. EPA action level is 0.05 mg/L. Chronic exposure to high manganese in drinking water has been associated with neurological effects, particularly in children and infants.
How is a manganese blood test performed and interpreted?
A manganese blood test is typically performed using a whole blood sample collected in a trace-element-free (royal blue top) tube to avoid contamination from metal in standard tubes. Whole blood manganese is preferred over serum because manganese is predominantly located inside red blood cells. Results are interpreted in the context of exposure history, symptoms, and occupation. Levels above 15 µg/L in whole blood often warrant further investigation, especially with neurological symptoms.