Functions

* Normal skeletal growth and development

* Essential for glucose utilization

 * Lipid synthesis and lipid metabolism

* Cholesterol metabolism

* Pancreatic function and development

* Prevention of sterility

* Important for protein and nucleic acid metabolism

* Activates enzyme functions

* Involved in thyroid hormone synthesis

Uses

* Infertility

* Impaired glucose metabolism

* Diseases of the skeletal structure, and impaired growth

* Pancreatic dysfunction

* Elevated blood pressure

* Atherosclerosis

* Reduced protein metabolism

* Reduced immune function

* Ataxia

* Selenium deficiency

* Depressed activity of mammary glands in nursing mothers

* Mitochondrial abnormalities

Manganese deficiency has been associated with cancer, rheumatic conditions, rickets, morning sickness, jaundice, and diabetes.

Excessive ingestion of iron, combined with hypochlorhydria, can cause an imbalance in the Mn/Fe ratio.

Deficiency

Deficiency symptoms:

* Ataxia

* Fainting

* Hearing loss

* Weak tendons and ligaments

* Possible cause of diabetes. Medical studies indicate that manganese deficiency impairs glucose metabolism and reduced insulin production.

* Manganese deficiency has been linked to myasthenia gravis. Manganese activates several enzyme systems and supports the utilization of vitamin C, E, choline, and other B-vitamins. Inadequate choline utilization reduces the acetylcholine

synthesis, causing conditions such as myasthenia gravis (loss of muscle strength).

* Manganese and zinc therapy can reduce copper levels and therefore manganese and/or zinc may be of therapeutic value in the treatment of symptoms linked to excess copper.

Antagonists

Sensitive to food processing; almost 90% is lost from both grain and sugar after processing. Manganese may inhibit absorption of copper, iron and zinc.

Co-factors

Manganese functions with vitamin K to produce blood clotting factors.

Drug Interactions

None known.

Dose

Recommended Dietary Amount (in mg)

Infants, 0-5 months 0.5-0.7

Infants, 5-12 months 0.7-1.0

Children, 1-3 yrs. 1.0-1.5

Children, 4-6yrs. 1.5-2.0

Children, 7-10yrs. 2.0-3.0

Children, 11+ 2.5-5.0

Adults, both genders 2.5-5.0

Toxicity

Excess manganese interferes with the absorption of dietary iron. Long-term exposure to excess levels may result in iron-deficiency anemia. Increased manganese intake impairs the activity of copper metallo-enzymes. Manganese overload is generally due to industrial pollution. Workers in the manganese processing industry are most at risk. Well water rich in manganese can be the cause of excessive manganese intake and can increase bacterial growth in water.

Manganese poisoning has been found among workers in the battery manufacturing industry. Symptoms of toxicity mimic those of Parkinson's disease (tremors, stiff muscles) and excessive manganese intake can cause hypertension in patients older than 40. Significant rises in manganese concentrations have been found in patients with severe hepatitis and posthepatic cirrhosis, in dialysis patients and in patients suffering heart attacks.

Symptoms of increased manganese levels:

* Psychiatric illnesses

* Mental confusion

* Impaired memory

* Loss of appetite

* Mask-like facial expression and monotonous voice

* Spastic gait

* Neurological problems

Other manifestations include:

* Impaired thiamin (B1) metabolism

* Iron deficiency

* Increased demand for vitamin C and copper.

* Manganese toxicity can cause kidney failure, hallucinations, as well as diseases of the central nervous system. High hair  manganese levels indicate problems with calcium and/or iron metabolism.

Sources

Liver and kidneys are the primary meat source of manganese. Wheat germ, legumes, nuts, and black tea are good plant sources.

Manganese content of foods (mg/100g)

Wheat germ 9

Rolled oats 5

Wheat bran 4

Cereals 2.4-4

Soybeans 3

Wheat whole grain bread 2.3

Parsley 3

Pulses 1.3-2

Sorghum 1.9

Rye bread 1

Rice 1

Vegetables 0.05-0.75

Pasta 0.73

Fruit, berries 0.03-0.6s

White bread 0.6

Corn 0.5

Potatoes 0.15

Mushrooms 0.11

Oyster 0.6

Liver 0.25-0.36

Cheese 0.017-0.19

Fish 0.012-0.12

Kidneys 0.06-0.11

Meat 0.02-0.08

Cottage cheese 0.06

Turkey 0.03-0.05

Chicken 0.02

Whole milk 0.003