Manganese
Vitaminas e mineraisÚltima revisão: 7 de abril de 2026. Abordagem de fontes: contexto padrão de interpretação laboratorial, material médico de referência e orientações clínicas ou de saúde pública quando relevantes.
O que é Manganese?
Manganese is an essential trace mineral required for the activity of several important metalloenzymes, including manganese superoxide dismutase (MnSOD, the primary mitochondrial antioxidant enzyme), arginase (urea cycle), pyruvate carboxylase (gluconeogenesis), and glycosyltransferases (proteoglycan and glycoprotein synthesis critical for cartilage and bone formation). Manganese also activates numerous other enzymes as a nonspecific cofactor, though magnesium can often substitute in these roles.
Dietary sources of manganese include whole grains, nuts, legumes, tea, leafy vegetables, and pineapple. Absorption occurs in the small intestine via DMT1 (the same transporter used by iron), and homeostasis is primarily maintained by hepatic regulation of biliary excretion rather than by controlling absorption. Whole blood manganese is the preferred clinical specimen, as serum levels are very low and less reliable. Occupational exposure (welding, mining, steel manufacturing) is the most common cause of manganese toxicity, which causes a characteristic parkinsonian syndrome known as manganism.
Por que isso importa
Manganese plays a critical role as the cofactor for MnSOD, the primary antioxidant defense within mitochondria—without it, mitochondrial oxidative damage accumulates. Manganese is also essential for normal bone development and maintenance through its role in glycosyltransferases that synthesize proteoglycans in cartilage and bone matrix. While dietary deficiency is extremely rare in humans, manganese toxicity from occupational or environmental exposure is a well-documented cause of irreversible neurological damage that closely resembles Parkinson disease. The narrow therapeutic window of manganese (essential at low doses, toxic at higher levels) makes monitoring important in at-risk populations.
Faixas de referência normais
| Grupo | Faixa | Unidade |
|---|---|---|
| Adults (whole blood) | 4.7–18.3 | µg/L |
| Adults (serum) | 0.4–0.85 | µg/L |
As faixas de referência podem variar entre laboratórios. Sempre compare seus resultados com as faixas fornecidas pelo seu local de exame.
O que significam níveis altos de Mn
Causas comuns
- Occupational exposure (welding fumes, mining, steel/battery manufacturing)
- Contaminated drinking water
- Chronic liver disease (impaired biliary excretion)
- Prolonged parenteral nutrition with manganese
- Iron deficiency (increased intestinal absorption via shared transporters)
- Neonates and infants (immature biliary excretion)
Possíveis sintomas
- Manganism: bradykinesia, rigidity, tremor (resembles Parkinson disease)
- Psychiatric symptoms: irritability, aggression, hallucinations ("manganese madness")
- Cognitive impairment and memory loss
- Gait abnormalities (characteristic "cock walk")
- Headaches and insomnia (early symptoms)
- Hepatic dysfunction
O que fazer: Remove the source of exposure immediately—this is the most critical intervention. In occupational settings, ensure proper ventilation and respiratory protection. For parenteral nutrition, reduce or eliminate manganese supplementation and monitor levels. Chelation therapy with EDTA or para-aminosalicylic acid (PAS) has shown some benefit, but neurological damage from chronic exposure is often irreversible. Brain MRI typically shows T1-weighted hyperintensity in the globus pallidus, a hallmark finding. Levodopa is less effective for manganism than for Parkinson disease.
O que significam níveis baixos de Mn
Causas comuns
- Extremely restrictive diets (very rare cause of clinical deficiency)
- Chronic malabsorption (theoretical)
- Excessive iron or calcium supplementation (competitive inhibition)
Possíveis sintomas
- Impaired bone growth and skeletal abnormalities (observed in animals)
- Dermatitis
- Impaired glucose tolerance
- Altered lipid metabolism
- Impaired reproductive function (observed in animals)
O que fazer: Clinical manganese deficiency is exceptionally rare in free-living humans and has only been clearly documented in experimental settings. If suspected, ensure adequate dietary intake through whole grains, nuts, tea, and leafy vegetables. The adequate intake is 2.3 mg/day for men and 1.8 mg/day for women. Avoid excessive iron or calcium supplementation that could compete with manganese absorption. Most varied diets provide sufficient manganese.
Quando o exame de Mn é recomendado?
- In workers with occupational exposure to manganese (welding, mining)
- When parkinsonian symptoms occur in young individuals
- In patients on long-term parenteral nutrition
- When chronic liver disease may impair manganese excretion
- In environmental exposure investigations
- When unexplained neuropsychiatric symptoms are present in at-risk populations
Perguntas frequentes
Biomarcadores relacionados
Referências e abordagem de revisão
As páginas do glossário de biomarcadores são explicações educativas e devem ser interpretadas junto com as faixas de referência e observações fornecidas pelo seu laboratório e pelo seu médico. Para conhecer nossos padrões editoriais e processo de revisão, veja nossa Política editorial e a nossa revisão de conteúdo.
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Enviar resultados de exames →Aviso médico: Estas informações são apenas educativas e não substituem orientação, diagnóstico ou tratamento médico profissional. As faixas de referência podem variar entre laboratórios. Sempre converse com seu profissional de saúde sobre a interpretação dos seus resultados específicos.