Manganese Side Effects

Manganese is a mineral that is used by the body for bone formation, protein metabolism, energy production and other functions. Most people's bodies contain approximately 15 to 20 mg of manganese, roughly half of which is in the bones. The remaining 50 percent is concentrated in the kidneys, liver, pancreas, adrenal and pituitary glands. Manganese from foods or supplements is never toxic, but there are reported lung problems from inhaled manganese dust from mining, battery making and welding.

Dietary Needs

• There is no recommended daily allowance for manganese, however, the National Academy of Sciences has stipulated adequate intake (AI) levels and tolerable upper limit (TUL) levels for the mineral. Those values are as follows:

  AI TUL
  Infants 0-6mo 3 mcg prohibit supplements,
  no food guidelines

  Infants 7-12 mo 600 mcg prohibit supplements,
  no food guidelines

  Children 1-3 yrs 1.2 mg 2 mg
  Children 4-8 yrs 1.5 mg 3 mg

  Males 9-13 yrs 1.9 mg 6 mg
  Males 14-18 yrs 2.2 mg 6 mg
  Males 19 & up 2.3 mg 11 mg

  Females 9-18 yrs 1.6 mg 6 mg
  Females 19 & up 1.8 mg 11 mg
  not pregnant or lactating

  Females 2.0 mg 9 mg
  Pregnant or Lactating

Functions of Manganese in the Human Body

• Manganese helps the body use several of the B-vitamins, choline and vitamin C by activating the enzymes needed for processing those molecules. Manganese is also responsible for activating the enzymes, which are involved in the development of healthy bones. Manganese helps metabolize glucose, form urea and, according to Staying Healthy with Nutrition by Elson Haas, M.D., also may help protect cell membranes and the nerve coverings by acting as a protective antioxidant. It is thought that manganese also plays a role in the production of thyroxine, a chemical that is vital to the health of the thyroid

Signs of Deficiency

• Deficiency of manganese can manifest itself in several ways. Children with a severe deficiency of this mineral may experience seizures, blindness or may become paralyzed.

  Adults deficient in manganese can have hearing disturbances, such as hearing odd noises that aren't there. They may also suffer from dizzy spells or weakness. Other possible signs of low manganese include weight loss, irregular heartbeat or a decreased glucose tolerance.

  According to Haas, manganese deficiency in rats has been linked to sterility, a decrease in bone growth and health, poor brain function and decreased threshold for seizures. It is unsure what these results in rats means for humans.

Symptoms of Toxicity

• Although manganese toxicity is rare when the mineral is obtained solely from food sources, those who are exposed to the dust from manganese mine are susceptible. In countries where manganese is mined, such as Chile, it is well documented that an overdose of inhaled manganese can cause symptoms including weakness, anorexia, mania, insomnia, delusions and even hallucinations. Some people also experience symptoms of muscle rigidity, or tremors, similar to Parkinson's disease. This condition is treated by stopping the exposure to inhaled manganese and by giving the victim L-dopa, which converts to dopamine in the brain.

  A second source of manganese toxicity is through drinking water. It has been determined that manganese in drinking water at amounts more than 2 mg per liter of water can lead to problems similar to those from the inhaled mineral.

The Best Food Sources

• Manganese in levels that promote optimal health can be found in whole grains and nuts. Legumes, seeds, alfalfa and leafy greens such as spinach are also good sources.

  "Nutritional Herbology" by Mark Pedersen says that red raspberry leaves contain almost two times more manganese than any other herb, with 14.60 mg per 100 g of the leaf. This makes red raspberry leaf an excellent source of the mineral for those who use this herb.