Manganese

Functions

Manganese is associated with the formation of connective and skeletal tissues, growth, and reproduction.

It catalyzes detoxification of free radicals and may protect against some types of cancer.

Food Sources and Intakes

The manganese content of foods varies greatly. The richest sources are whole grains, legumes, nuts, and tea. Fruits and vegetables are moderately good sources. Relatively high amounts exist in instant coffee and tea. Animal tissues, seafood, and dairy products are poor sources. Human milk is relatively low in manganese. Intakes are often low for adolescent girls.

Deficiency

Symptoms of deficiency are weight loss, transient dermatitis, occasionally nausea and vomiting, a change in hair color, and slow hair growth. In addition, there is a correlation between low blood manganese and convulsions established that manganese is necessary for reproduction. Sterility develops in both sexes; striking skeletal abnormalities and ataxia characterize the offspring of mothers who are manganese deficient. Lower blood manganese levels may be associated with fetal intrauterine growth retardation and lower birth weight in humans.

Dietary Reference Intakes
The AIs for manganese are 2.3 mg/day for men and 1.8 mg/ day for women. For children 9 years of age and older the AIs are 1.9 to 2.2 mg/day for boys and 1.6 mg/day for girls. For children younger than 9 the AIs are 1.2 to 1.5 mg/day, depending on their age.