Manganese

Overview

Manganese is a co-factor that aids in the activation of a wide variety of enzymes. Manganese-containing enzymes influence many biological activities, including the synthesis of collagen, protein, mucopolysaccharides, cholesterol and fatty acids. It is also necessary for normal bone growth and the metabolism of amino acids.

The average human body only contains approximately 20mg of manganese, most of which is stored in the bones. Smaller amounts concentrate in the pituitary, liver, pancreas, and intestinal mucosa. Absorption occurs throughout the entire small intestine.

Dosage Info

Dosage Range

Dosages commonly used in clinical studies range from 250mcg-5mg daily. (1)

Most Common Dosage

2mg daily

Dosage Forms

Tablets, capsules, and powders.

Adult RDI

None established

Adult ODA

None established

RDA

  • Infants < 6 months: 0.003mg (Adequate Intake, AI)
  • Infants 7-12 months: 0.6mg (AI)
  • Children 1-3 years: 1.2mg (AI)
  • Children 4-8 years: 1.5mg (AI)
  • Males 9-13 years: 1.9mg (AI)
  • Females 9-18 years: 1.6mg (AI)
  • Males 14-18 years: 2.2mg (AI)
  • Males >19 years: 2.3mg (AI)
  • Females >19 years: 1.8mg (AI)
  • Pregnancy: 2mg (AI)
  • Lactation: 2.6mg (AI)

Interactions and Depletions

Interactions

Active Forms

Manganese aspartate, arginate, citrate, chloride, gluconate, glycinate, picolinate, and sulfate.

Absorption

Manganese absorption takes place in the small intestine. Chelation with histidine and citrate reportedly enhance manganese absorption whereas calcium cobalt and iron compete with manganese and therefore can inhibit its absorption. Intestinal absorption is hindered by ingestion of calcium, phosphate, iron, and phytate.

Toxicities & Precautions

General

Manganese is nontoxic for most people. Manganese toxicity has occurred in miners due to the inhalation of manganese dust. Toxicity can produce dementia, psychiatric disorders resembling schizophrenia, and neurologic disorders resembling Parkinson’s disease.

Functions in the Body

Antioxidant

Cofactor in mitochondrial superoxide dismutase, for optimal functioning of one of the body’s most important antioxidant enzymes. (2)

Connective Tissue and Cartilage

Necessary for the production of mucopolysaccharides, glycoproteins, and lipopolysaccharides, for the growth and maintenance of connective tissue and cartilage.

Thyroid

Necessary in the synthesis of thyroxine, the principal hormone of the thyroid gland.

Regulation of Blood Clotting

In conjunction with vitamin K, manganese plays a role in the synthesis of prothrombin and the regulation of blood clotting.

Bone Growth and Development

Influences the activity of osteoblasts and osteoclasts for normal bone growth and development.

Fatty Acid Synthesis

Involved with the production of dopamine and melanin and in the synthesis of fatty acids.

Clinical Applications

Epilepsy

Individuals with epilepsy have low manganese levels and manganese was lowest in those with most frequent seizures. (3) , (4) , (5) , (6)

Osteoporosis

Manganese is necessary for the synthesis of mucopolysaacharides, which provide the structure for bone calcification. (7) Manganese-induced deficiency in animals reduces the amount of calcium in bones, resulting in thinner bones. (8) , (9) Serum concentrations of manganese in osteoporotic women have been reported to be 75 percent less than manganese levels in non-osteoporotic women. (10)

Diabetes Mellitus

Manganese, which is an important cofactor in enzymes that regulate glycolysis, is lower in diabetic individuals. (11) Deficiency leads to impaired glucose tolerance, which is corrected with supplementation. (12)

Symptoms and Causes of Deficiency

Although widely involved in bilogical activities, manganese deficiency in humans is relatively uncommon because the mineral magnesium is capable of substituting for manganese in many of manganese's varoius enzyme-related functions.

    The most notable symptoms of manganese deficiency are skeletal abnormalities, such as loss of muscle coordination, sprains, strains, and weak ligaments. These problems develop due to reduced synthesis of collagen and mucopolysaccharides

Dietary Sources

Manganese is widely distributed in foods of plant and animal origin. Best food sources include nuts, whole grain breads and cereals, dried beans and peas, vegetables, raisins, pineapple, and nuts.

References

  1. View Abstract: Strause L, Saltman P, Smith KT, Bracker M, Andon MB. Spinal bone loss in postmenopausal women supplemented with calcium and trace minerals. J Nutr. Jul1994;124(7):1060-1064.
  2. View Abstract: Luk E, Carroll M, Baker M, Culotta VC. Manganese activation of superoxide dismutase 2 in Saccharomyces cerevisiae requires MTM1, a member of the mitochondrial carrier family. Proc Natl Acad Sci U S A. Sep2003;100(18):10353-7.
  3. View Abstract: Papavasilious PS, et al. Seizure Disorders and Trace Metals: Manganese Tissue Levels in Treated Epileptics. Neurology. Nov1979;29(11):1466-73.
  4. View Abstract: Papavasilious PS, et al. Seizure Disorders and Trace Metals: Manganese Tissue Levels in Treated Epileptics. Neurology. Nov1979;29(11):1466-73.
  5. View Abstract: Dupone CL, et al. Blood Manganese Levels in Children with Convulsive Disorder. Biochem Med. Apr1985;33(2):246-55.
  6. View Abstract: Carl GF, et al. Manganese and epilepsy: brain glutamine synthetase and liver arginase activities in genetically epilepsy prone and chronically seizured rats. Epilepsia. May1993;34(3):441-6.
  7. Leach RM Jr. Role of Manganese in Mucopolysaccharide Metabolism. Fed Proc. Jun1971;30(3):991-94.
  8. Strause L , Saltman P. Biochemical Changes in Rat Skeleton Following Long-term Dietary Manganese and Copper Deficiencies. Fed Proc. 1985;44:752.
  9. View Abstract: Keen CL, et al. Nutritional aspects of manganese from experimental studies. Neurotoxicology. Apr1993;20(2-3):213-23.
  10. Freeland-Graves J. Manganese: An Essential Nutrient for Humans. Nutrition Today. Dec1988:13-19.
  11. Wimhurst JM, et al. Comparison of Ability of Mg and Mn to Activate the Key Enzymes of Glycolysis. FEBS Lett. Nov1972;27(2):321-26.
  12. View Abstract: Baly DL, et al. Effect of Manganese Deficiency on Insulin Binding, Glucose Transport and Metabolism in Rat Adipocytes. J Nutr. Sep1990;120(9):1075-79.