Vitamins, Minerals and Dietary Supplements
What is manganese?
Manganese is a trace element and essential mineral. In its natural state,
it is grayish-white in color and resembles iron, but it is not magnetic.
It is absorbed in the small intestine and is stored in small amounts in
the bones, pituitary gland, pancreas and liver.
Why do we need it?
Manganese is needed for the formation of healthy skin, nerves, bones
and cartilage. It also works in conjunction with zinc and copper to activate
an antioxidant named superoxide dismutase, which prevents free radicals
from destroying cell organs.
In addition, manganese plays an important role in the synthesis of cholesterol
and fatty acids, and is essential for the utilization of choline, thiamin,
biotin, and vitamins C and E. It helps activate enzymes that regulate
blood sugar, energy metabolism and function of the thyroid gland.
How much manganese should I take?
There is currently no recommended daily allowance (RDA) for manganese.
However, the National Academy of Sciences has deemed the following amounts
to be safe and adequate in a normal diet:
- Adult men: between 2-5 milligrams/day
- Adult women: between 2-5 milligrams/day
- Children aged 7-10: between 2-3 milligrams/day
- Infants: between 0.3-1.0 milligrams/day
- Pregnant/lactating women: between 2-5 milligrams/day
What are some good sources of manganese?
The best dietary sources of manganese are nuts, whole grains, dried fruits,
pineapples and leafy green vegetables. Beets, beans and brown rice are
other good sources.
What can happen if I donšt get enough manganese?
Manganese deficiency is extremely rare. Some animal studies have shown
that a diet devoid of manganese can lead to slow or stunted growth, skeletal
abnormalities and paralysis. Other studies have linked manganese deficiency
to osteoporosis, loss of hair color, and impaired growth of hair and nails.
What can happen if I take too much?
Excessive amounts of manganese can lead to side effects such as dementia,
hallucinations and psychiatric disorders, a condition sometimes known
as "manganese madness." Research has also suggested that individuals
with cirrhosis may not be able to properly excrete manganese. Patients
with this condition should not take manganese supplements.
- Recommended Dietary Allowances, 10th ed. Washington,
D.C.: National Academy Press, 1989.
- Murray M. Encyclopedia of Natural Medicine,
2nd ed. Rocklin, CA: Prima Publishing, 1998.
- Murray M. Encyclopedia of Nutritional Supplements.
Rocklin, CA: Prima Publishing, 1996.
- Raloff J. Reasons for boning up on manganese. Science
Sep 1986, 199 [review].
- Krieger D, Krieger S, Jansen O, et al. Manganese and
chronic hepatic encephalopathy. Lancet 1995;346:270-74.
- Freeland-Graves JH. Manganese: an essential nutrient
for humans. Nutr Today 1989;23:13-19 [review].