Manganese is an essential mineral that is not produced in our body so we need to get it from our diet or supplements. Our body only needs a small amount of this mineral. However, it has several important functions: manganese helps in the metabolism of carbohydrates and amino acids and is needed for bone formation. It also plays a role in maintaining immune function and blood clotting. 

The human body can only store up to 20 mg of manganese. The rest is removed from the body through faeces and urine. About 40% of the total manganese in our body is stored in our bones. The rest is stored in the kidneys, liver and brain.

As important as this mineral is, the total manganese intake should be kept as per daily recommended allowance as excessive amounts of manganese can lead to toxicity.

  1. RDA of manganese: How much manganese to take per day
  2. Manganese rich foods
  3. Manganese benefits and uses
  4. Manganese side effects

The recommended daily allowance or RDA of a nutrient is the amount of that nutrient that should be consumed every day to maintain optimum health. The RDA generally varies as per the age and sex of the individual. There is no RDA for manganese. However, the Office of Dietary Supplements, National Institutes of Health, US, mentions the following limits for adequate intake of manganese:

Age Male Female
Babies up to 6 months 0.003 mg 0.003 mg
7 months to 1 year 0.6 mg 0.6 mg
1 to 3 years 1.2 mg 1.2 mg
4 to 8 years 1.5 mg 1.5 mg
9 to 13 years 1.9 mg 1.6 mg
14 to 18  years 2.2 mg 1.6 mg
19 years and above 2.3 mg 1.8 mg

Pregnant women should take about 2 mg of manganese and breastfeeding women should take about 2.6 mg of manganese per day.

Adequate intake refers to the intake level of a nutrient that is suggested in the absence of sufficient evidence to establish an RDA.

Experts suggest that plant-based foods contain a higher concentration of manganese than foods sourced from animals. Some amount of manganese is also present in drinking water in some areas.

Here is a list of foods you can obtain your daily dose of manganese from:

Manganese supplements are usually not needed since a lot of foods in our diet contain this mineral. However, you may take these supplements if your doctor advises you to. Manganese supplements are available both alone and in the form of multivitamin and mineral tablets. The only-manganese ones provide anywhere between five to 20 mg of manganese while the multivitamin tablets have about one to 4.5 mg of manganese.

Manganese is needed for the healthy growth and development of the body. This mineral also helps in the functioning of various enzymes. 

Let us have a look at the various effects of manganese on health:

Manganese helps in metabolism

Manganese activates a lot of enzymes involved in the metabolism of amino acids (proteins), carbohydrates and cholesterol in the body. It also speeds up the synthesis of vitamin C, vitamin B, and proteins in the body and plays a role in hematopoiesis (production of blood).

Manganese-activated enzymes are important in the process of gluconeogenesis, which is the production of glucose from substances other than carbohydrates.

It is also needed by an enzyme called arginase that helps eliminate excess urea from the body. Urea is a nitrogen-containing compound that is produced as a result of amino acid metabolism in the body. High levels of urea (hyperuricemia) may otherwise lead to gout. Manganese also helps in the formation of the neurotransmitter glutamate via the enzyme glutamate synthetase. Neurotransmitters are compounds that help pass on signals and information between nerve cells (neurons).

Additionally, manganese affects deiodinase enzymes which are responsible for activating the thyroid hormones. Thyroid hormones are responsible for controlling various metabolic functions in the body.

Manganese effects on blood sugar levels

Since manganese is involved in carbohydrate, fat and protein metabolism, the deficiency of this nutrient is associated with abnormal blood sugar levels. Diabetes-like glucose intolerance has been found in animals with manganese deficiency. However, in humans, the evidence is not as clear.

Indeed, there is some contradictory evidence in science: a study done in China found that higher levels of manganese are associated with an increased risk of diabetes, whereas a study published in the journal Biological Trace Element Research said that manganese-deficiency plays a role in the development of diabetes mellitus. In an older study with 57 diabetics, no significant link was found between manganese levels and diabetes.

Manganese effects on bone health

Manganese plays an important role as a cofactor for various enzymes involved in bone and cartilage formation and mineralisation. Animal studies have shown that a deficiency of manganese leads to osteopenia (low bone density). It also prevents the formation of cartilage. 

Women with osteoporosis have also been found to have lower manganese levels than otherwise healthy women of almost the same mean age. On the other hand, a study done on a group of postmenopausal women found almost no difference between plasma manganese levels in those with and without osteoporosis. 

A study published in The Journal of Nutrition indicated that bone loss in postmenopausal women can be reduced by giving them trace minerals like zinc and manganese along with calcium. However, more studies are needed to ascertain the effects of manganese levels on bone mineral density or bone health in general.

Manganese effects on brain

Manganese is one of the minerals needed for the development of the human brain. It plays an important role in the production of neurotransmitters. 

According to a review study published in the journal Current Environmental Health Reports, manganese exposure is negatively associated with cognition and both high and low manganese levels can lead to reduced intellectual functioning in children.

An excess of manganese is suggested to have a role in Parkinson’s and Huntington’s disease

Furthermore, a study suggested that manganese deficiency may have some role in epilepsy. Though more studies are needed to understand if the deficiency triggers epilepsy.

Manganese for wound healing

Manganese has various roles in wound healing:

  • First, it plays an important role in blood clotting along with vitamin K.
  • Second, manganese activates the enzymes glycosyltransferases, which are involved in the production of glycosaminoglycan. The latter is a type of polysaccharide (a sugar) that helps promote the healing of wounds.
  • Finally, manganese helps in the activation of prolidase, an enzyme that is responsible for providing proline (an amino acid) for the synthesis of collagen. Collagen is a structural protein in the body—it is needed for making connective tissues like cartilages and bones. 

Manganese as an antioxidant

Manganese superoxide dismutase is the main enzyme in mitochondria (a cell organelle) that is responsible for neutralizing free radicals. Free radicals are a type of oxygen that is harmful to the body—it causes oxidative stress and deteriorates organ functions over time. Excess free radicals also lead to inflammation. So, manganese may help manage inflammation too.

In fact, as per a study done in Japan, superoxide dismutase may be a potential therapeutic agent against inflammation.

Read more: Antioxidants benefits and side effects

There has been no evidence of manganese toxicity through food. Most cases are seen in those who are exposed to excess manganese in drinking water or through occupational exposure via the respiratory tract such as in those working in the mining or welding industry. 

Excess manganese affects the nervous system and leads to symptoms like:

Those with liver disease cannot properly metabolise manganese in their body and are hence prone to toxicity from this mineral. Also, if you have iron deficiency, your body would start absorbing more manganese.

These are the tolerable upper limits of manganese by age, according to the NIH (the limits are same for males and females):

Age Tolerable upper limit
Babies up to 6 months Not established
7 months to 1 year Not established
1 to 3 years 2 mg
4 to 8 years 3 mg
9 to 13 years 6 mg
14 to 18  years 9 mg
19 years and above 11 mg

The upper limit for manganese intake in pregnant and lactating women is the same as that of other people: 11 mg after the age of 19.

References

  1. National Research Council (US) Subcommittee on the Tenth Edition of the Recommended Dietary Allowances. Recommended Dietary Allowances: 10th Edition. Washington (DC): National Academies Press (US); 1989. 2, Definition and Applications
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  3. National Institutes of Health. Office of Dietary Supplements. [Internet]. U.S. Department of Health & Human Services; Manganese.
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  11. Linus Pauling Institute: Micronutrient Information Center [Internet]. Oregon State University. Corvallis. Oregon. USA; Manganese.
  12. Kosir MA, Quinn CC, Wang W, Tromp G. Matrix glycosaminoglycans in the growth phase of fibroblasts: more of the story in wound healing. J Surg Res. 2000;92(1):45-52. PMID: 10864481.
  13. Yasui K, Baba A. Therapeutic potential of superoxide dismutase (SOD) for resolution of inflammation. Inflamm Res. 2006;55(9):359-363. PMID: 17122956.
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  15. Institute of Medicine (US) Panel on Micronutrients. Dietary Reference Intakes for Vitamin A, Vitamin K, Arsenic, Boron, Chromium, Copper, Iodine, Iron, Manganese, Molybdenum, Nickel, Silicon, Vanadium, and Zinc. Washington (DC): National Academies Press (
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