Manganese is an underrated, but essential, trace mineral. It enables the body to make effective use of vitamins C, B I, biotin and choline. Without manganese, the body cannot make fat, sex hormones or, in women, breast milk. It appears to help the body to neutralize the damaging substances known as free radicals, to prevent diabetes and to preserve normal nerve function.
AVAILABILITY IN FOODS
As with iron, absorption of manganese is poor, with only about 15-30 per cent of intake being used by the body. However, it is widely available in plant foods, including nuts, whole grains, pulses, leafy greens, especially spinach and alfalfa, tea and coffee. Up to 90 per cent of manganese in whole grains is lost during milling. Its absorption into the body can be reduced by the simultaneous intake of large amounts of calcium (high in milk), phosphorus (high in meats and fizzy drinks), zinc, cobalt and soy protein. It competes for the same absorption pathway as iron: either mineral when taken in large amounts will inhibit the absorption of the other. The level of manganese in the soil can be depleted by the use of chemical fertilizers, or made unavailable to plants by over-use of lime.
WHAT IF YOUR INTAKE IS TOO LOW?
Manganese deficiency is rare. Symptoms include poor growth of bones, problems with cartilage and the discs between the vertebrae (bones in the spine), alterations in brain and muscle function, birth defects, reduced control of glucose levels in the blood, hearing problems and reduced fertility. Serious deficiencies in infants can cause paralysis, convulsions, blindness and deafness. Lack of manganese can lead to diabetes and atherosclerosis.
WHEN EXTRA MAY BE NEEDED
- While breast feeding
- If you take calcium or phosphorus supplements
(Pregnant and breast feeding women should consult a doctor, midwife, or qualified nutritionist before taking any mineral or vitamin supplement.)
CAN TOO MUCH BE TOXIC?
Although manganese appears to be relatively non-toxic when eaten, a condition that is sometimes known as 'manganese madness' occurs in those who work in manganese mines and inhale it.
USING A SUPPLEMENT
Manganese is best taken as part of a well balanced mineral and vitamin supplement.