Manganese
What does it do?
Manganese is needed for healthy skin, bone, and cartilage formation, as
well as glucose tolerance. It also helps activate superoxide dismutase
(SOD)—an important antioxidant
enzyme.
Where is it
found? Nuts,
wheat germ, wheat bran, leafy green vegetables, beet tops, pineapple, and
seeds are all good sources of manganese.
Who is
likely to be deficient? Many people consume less than the 2.5–5 mg of
manganese currently considered safe and adequate. Nonetheless, clear
deficiencies are rare. Individuals with osteoporosis
sometimes have low blood levels of manganese, suggestive of
deficiency.1
How much is usually
taken? Whether most people would benefit from manganese
supplementation remains unclear. The 5–15 mg often found in high-potency
multivitamin/mineral
supplement is generally considered to be a reasonable level for those
wishing to supplement manganese.
Are there any side effects or interactions? Amounts found in
supplements (5–20 mg) have not been linked with any toxicity. Excessive
intake of manganese can lead to the rare side effects of dementia and
psychiatric symptoms. Preliminary research suggests that individuals with
cirrhosis may not be able to properly excrete manganese; until more is
known, these people should not supplement manganese.2
Several minerals, such as
calcium
and iron,
and possibly zinc reduce
the absorption of manganese.3
Zinc and copper
work together with manganese to activate superoxide dismutase.
