Manganese: How much is too much?

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Excess of Manganese (Mn) is Toxic

Manganese is one of the necessary nutrients that should be present in our diet in small amounts on daily basis. There are many benefits for manganese such as bone production, skin integrity, blood sugar control, carbohydrates, cholesterol control or protection against free radical damage. Many articles are present on the internet to tell about benefits of manganese in our lives. But do you ever think what it can do to us if consumed in excess amount? As much as it is beneficial, it is risky as hell too.

Manganese, when increases in your bloodstream after certain limit can lead to chronic health conditions.

Functions controlled by Manganese:

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Things which are controlled by manganese are listed below:

  • Healthy bone structure
  • Bone metabolism
  • Formation of connective tissues
  • Absorption of calcium
  • Functioning of thyroid gland
  • Functioning of sex hormones
  • Controls blood sugar
  • Controls the metabolism of fats and carbohydrates
  • Reduces the stressful conditions of PMS
  • Improves Thyroid health

Right amount to consume daily:

National Institutes of Health’s Office of Dietary Supplements suggests a different amount of manganese intake by males, females or children on daily basis.

Children and Infants:

  • 0-6 months: 0.003 mg
  • 7 months-1 yr: 0.6 mg
  • 1-3 yr: 1.2 mg
  • 4-8 yr: 1.5 mg
  • Males:
    • 9-13 yr: 1.9 mg
    • 14-18 yr: 2.2 mg
  • Females:
    • 9-18 yr: 1.6 mg


  • Males: 2.3 mg
  • Females: 1.8 mg
  • Pregnant Women: 2 mg
  • Breastfeeding Women: 2.6 mg

In any condition, it should not exceed 10 mg per day, else it can risk nervous system and cause many side effects.

Apart from supplements, natural resources of food such as foods with a lot of fiber are rich in it.

Natural food high in Manganese:

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  • Seafood
  • Almonds
  • Raspberries
  • Garlic
  • Grapes
  • Beetroot
  • Strawberries
  • Turmeric
  • Cucumber
  • Banana
  • Kiwi
  • Carrots
  • Coconuts
  • Brown Rice
  • Hazelnuts
  • Pumpkin seeds
  • Tofu
  • Beans
  • Whole Grains
  • Whole-Wheat Bread
  • Fish
  • Spinach
  • Black/ Brewed Tea

It should not be taken as a supplement or as a medication until subscribed by a physician.

Symptoms of Deficiency of Manganese:

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  • High Blood Pressure
  • Heart ailment
  • Muscular contraction
  • Bone malformation
  • High cholesterol
  • Poor eyesight
  • Hearing problem
  • Memory loss
  • Shivers and tremors
  • Infertility in women
  • Pancreatic damage
  • Osteoporosis

Risk of the high dose of Manganese:

The high dose of Manganese primarily affects the central nervous system. It doesn’t show effects at an early stage. It is a slow process and may take months or years.

High dose of manganese can be toxic which can lead to a permanent neurological disorder: Manganism.


Tremors, difficulty in walking, facial muscle contraction, change in behaviour (irritation), aggressive nature, hallucinations, uncontrollable laughter, impulsivity, insomnia or violent behaviour. In most severe cases, it can lead to coma.

Exposure to Manganese:

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  • Inhalation of fumes from welding
  • Environmental Exposures
  • Inhaling high concentration manganese dust

These can cause neurological effects or impairment in lung function. Lung infections can further lead to bronchitis, which can further cause Manganic Pneumonia.

High dose of Manganese in diet:

If consumed too much dietary manganese, it is responsible for causing heart infection. The bacterium known as Staphylococcus aureus (staph) affects the heart.

Mouse Model:

According to a study done on mice, the mice that consumed a diet with 3 times high manganese amount than normal, got infected with staph and died.

Eric Skaar, Ph.D., MPH, Ernest W. Goodpasture Professor of Pathology, said, “It’s striking that a single dietary change can inactivate one of the most powerful branches of  innate immune defense and lead to fatal infections.” He suggested, “The human body does a wonderful job of regulating nutrient levels, and a traditional Western diet has plenty of minerals in it. The idea of super-doing nutrients needs to be given careful consideration.”

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Excess of manganese in diet can shut down the immune system’s response to reactive oxygen. The defense against pathogens is also interrupted if the manganese increases after a certain limit in the blood. Now, the immune system is not able to respond to reactive oxygen, therefore, the bacteria stays at the infected site. Skaar said, “Neutrophils pour into the site of infection and blast the bacteria with reactive oxygen species.”  But an excess of manganese stops this reaction.

As per Skaar, it’s still a mystery how high manganese affects staph infection of a single organ.

The research is still going on to see the more side effects of manganese, if consumed in dietary plans in excess amount, apart from heart diseases.

Therefore, whether in form of supplements or medication or even in diet plans, keep the amount of manganese (Mn) under control: not too low, not too high, as both conditions can lead to health issues.

Consult your physician and dietician before making changes in your drugs or diet especially in case of Mn because it can cause fatal results.


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