Manganese Health Article

Preparations

The optimum daily dosage of manganese has not been established with certainty. While there is no RDA or Daily Value (DV) for manganese, the U.S. government has established what is called an Estimated Safe and Adequate Dietary Intake (ESADDI). In adults and children age 11 and over, the ESADDI for manganese is 2–5 mg a day. Adequate intake for younger children varies with age. Daily dosage is 2–3 mg in youngsters aged seven to 10, 1.5–2.0 mg for those who are four to six, and 1.0–1.5 mg in children aged one to three. A pediatrician should be consulted to determine how much manganese is required in infants younger than one year of age.

Even without taking supplements, most women get about 2.2 mg a day of manganese through their diets, while men consume about 2.8 mg. Vegetarians and people who consume large amounts of whole-grain foods may get as much as 10–18 mg a day. Some authorities believe it is better for people to avoid manganese supplements altogether and increase their intake of foods known to contain significant amounts of the mineral. Manganese-rich foods and drinks include peanuts, pecans, pineapples and pineapple juice, shredded wheat and raisin bran cereals, and oatmeal. Other good sources include rice, sweet potatoes, spinach, whole wheat bread, and lima, pinto, and navy beans. Meat, poultry, fish, and dairy products are considered poor sources. Getting too much manganese through food and drink is not considered a significant risk because the mineral is present only in small amounts in plants and animals.

Some people take as much as 50–200 mg of manganese for several weeks to help treat muscle sprains or strains, but the safety and effectiveness of taking dosages this high are unknown.

Precautions

Manganese is not known to be harmful when taken in recommended dosages. Extremely high intake of the mineral, however, has resulted in cases of idiopathic Parkinson's disease. Recent studies indicate that high levels of manganese alter the blood-brain barrier, lowering the iron content of blood plasma while allowing the iron content of cerebrospinal fluid to rise. These cases of manganese-induced parkinsonism are usually limited to miners who inadvertently breath manganese-rich dust or people who drink contaminated water from wells. People who eat a manganese-rich diet are not considered at risk for these types of side effects. In fact, most foods high in manganese are believed to contribute to good health.

Side effects

When taken in recommended dosages, manganese is not associated with any bothersome or significant side effects.

Interactions

Manganese interacts with certain drugs and dietary supplements. People who take oral contraceptives or antacids may require higher intake of manganese. More of the mineral may also be needed in people who also take phosphorus, fiber, copper, iron, zinc, magnesium, or calcium.

BOOKS

Murray, Michael T. Encyclopedia of Nutritional Supplements. California: Prima Publishing, 1996.

PERIODICALS

Akram, M., C. Sullivan, and G. Mack, et al. "What is the Clinical Significance of Reduced Manganese and Zinc Levels in Treated Epileptic Patients?" Medical Journal of Australia (1989): 113.

Freeland-Graves, J. H., and J. R. Turnlund. "Deliberations and Evaluations of the Approaches, Endpoints and Paradigms for Manganese and Molybdenum Dietary Recommendations." Journal of Nutrition (1996): 2435S–2440S.

Penland, J. G., and P. E. Johnson. "Dietary Calcium and Manganese effects on Menstrual Cycle Symptoms." American Journal of Obstetrics and Gynecology (1993): 1417–23.

Rivera, Juan A., Teresita Gonzalez-Cossio, Mario Flores, et al. "Multiple Micronutrient Supplementation increases the Growth of Mexican Infants." American Journal of Clinical Nutrition 74 (November 2001): 657.

Strause, L, P. Saltman, and K. T. Smith, et al. "Spinal Bone Loss in Postmenopausal Women Supplemented with Calcium and Trace Minerals." Journal of Nutrition (1994): 1060–1064.

Zheng, Wei. "Neurotoxicity of the Brain Barrier System: New Implications." Journal of Toxicology: Clinical Toxicology 39 (December 2001): 711–720.

ORGANIZATIONS

NIH Osteoporosis and Related Bone Diseases National Resource Center. 1232 22nd St. NW, Washington, DC 20037-1292.

OTHER

American Society for Nutritional Sciences. <http://www.nutrition.org>.

Discovery Health. <http://www.discoveryhealth.com>.

Greg Annussek

Rebecca J. Frey, PhD