Manganese benefits, sources and side effects

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.

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 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 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 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.