Manganese is a mineral nutrient, required in small amounts, but extremely important to enzyme activity. Mitochondria, the cell’s energy-producing engines, are highly susceptible to oxygen damage.
Manganese superoxide dismutase is the antioxidant enzyme that protects mitochondria from damage. Other manganese-dependent enzymes metabolize carbohydrates, cholesterol and amino acids.
Manganese also plays a role in bone formation and wound healing.
Recommended Dietary Allowances for Manganese
Which Foods Have Manganese?
Coconut meat, dried
Rice, white or brown
Black eyed peas
Coconut meat, fresh
What Happens If You Don’t Get Enough Manganese?
Manganese deficiency in humans, due to poor intake, is not common. Studies using manganese deficient diets found adverse effects on bone mineralization and glucose tolerance.
Manganese and iron are absorbed from the digestive tract by the same transport system, and a very high iron intake from supplements has been linked to lower manganese in the blood and lower manganese superoxide dismutase activity.
Low blood manganese is also associated with osteoporosis in some other studies. Bone strength depends on adequate supply of several different minerals, so manganese alone is unlikely to prevent osteoporosis. A bigger issue with manganese is excess intake. Intake of more than 11 mg per day is considered unsafe.
Symptoms of manganese toxicity include tremors similar to Parkinson’s disease, as well as irritability, balance problems and hallucinations. People with liver disease can’t excrete excess manganese and could develop toxicity. Most people develop manganese toxicity due to work-place exposures, after inhaling manganese-laden dust. A balanced diet is unlikely to lead to excess intake.