Manganese is a mineral that is involved in many enzyme systems in the body. It is found in many natural sources, but appears only in very small amounts in human tissue. The human body contains 15 to 20 milligrams of manganese, most of which are located in the bones, and the rest - in the kidneys, liver, pancreas, pituitary and adrenal glands.
Functions of manganese
- Activation of enzymes. Manganese activates the enzymes responsible for the absorption of some essential nutrients, including biotin, thiamin, ascorbic acid and choline. It is a catalyst for the synthesis of fatty acids and cholesterol, facilitates the metabolism of proteins and carbohydrates, and can also participate in the production of sex hormones and maintaining reproductive health. In addition, manganese activates enzymes known as glucosyltransferase and xylosyltransferase that are important for bone formation. It is also associated with the production of thyroid hormones known as thyroxine and maintaining the health of nerve tissue.
- Component of metalloenzymes - manganese has additional functions as a constituent of the following metalloenzymes: arginaza /enzyme in the liver responsible for creating urea/, glutamine synthetase; phosphonenolpyruvate decarboxylase /enzyme involved in the metabolism of blood sugar/; superoxide dismitaza /enzyme with antioxidant/.
Manganese deficiency is associated with nausea, vomiting, poor glucose tolerance (high blood sugar), skin rash, loss of hair, low cholesterol, dizziness, hearing loss and impaired function of the reproductive system. Severe manganese deficiency in infants can lead to paralysis, seizures, blindness and deafness.
It is important to emphasize, however, that manganese deficiency is very rare in humans and usually does not develop.
Most cases of manganese toxicity are observed in industrial workers exposed to manganese dust. These workers develop problems, like nervous system disease similar to Parkinson's.
Tolerable upper intake levels (UL) for manganese:
- Infants: they should not be given manganese supplements
- 1-3 years: 2 mg
- 4-8 years: 3 milligrams
- 9-13 years: 6 mg
- 14 to 18 years, including pregnant and lactating women: 9 milligrams
- Over 19 years, including pregnant and lactating women: 11 milligrams
Significant amounts of manganese may be lost in food processing, especially in the processing of whole grain crops for the production of flour or cooking of legumes.
Like zinc, manganese is a mineral that can be excreted in significant quantities through sweat and individuals who go through periods of excessive sweating may be at increased risk of manganese deficiency. Also, people with chronic diseases of the liver and gallbladder may require a large amount of manganese.
The effect of oral contraceptives and antacids (eg, Tums) can affect the absorption of manganese.
Benefits of manganese
Manganese may play an important role in the prevention and/or treatment of the following diseases: allergies, asthma, diabetes, epilepsy, heart disease, multiple sclerosis, osteoporosis, premenstrual syndrome, rheumatoid arthritis, schizophrenia, stress, etc..
As a dietary supplement, manganese occurs in complex with sulfate, chloride, picolinate, gluconate and amino acids.
Foods rich in manganese
Excellent sources of manganese include: mustard, kale, raspberries, pineapple, lettuce, spinach, turnip greens, maple syrup, molasses, garlic, grapes, summer squash, strawberries, oats, beans, brown rice, beans, cinnamon, thyme, mint and turmeric.
Good sources of manganese include: cucumber, peanuts, millet, barley, figs, bananas, kiwi, carrots and black beans.