Manganese is ubiquitous in the environment. It is the twelfth most abundant element on earth and the fifth most abundant metal. It is found in most water supplies, soil, steel alloys, bricks, batteries, glassware cleaners, and paints.
Manganese is an essential nutrient as several enzymes have been found that depend on manganese for their catalytic or regulatory function. Manganese is required to form healthy cartilage and bone and is part of the urea cycle. It aids in the maintenance of mitochondria and the production of glucose and plays a key role in wound healing. As an essential nutrient, manganese is added to certain foods and nutritional supplements. Interestingly, some vegetarians can have diets richer in manganese than those with omnivorous diets. Table 1 shows adequate intake levels for manganese by age.
While low levels of manganese intake are necessary for human health, high manganese levels are toxic.
Absorption:
Most of the manganese in the diet is not absorbed. The trace amounts that are absorbed are excreted in the urine.
Table 1. Adequate Intake (AI) Levels of Manganese.| Life Stage | Age | Males (mg/day) | Females (mg/day) |
| Infants | 0-6 months | 0.003 | 0.003 |
| Infants | 7-12 months | 0.6 | 0.6 |
| Children | 1-3 years | 1.2 | 1.2 |
| Children | 4-8 years | 1.5 | 1.5 |
| Children | 9-13 years | 1.9 | 1.6 |
| Adolescents | 14-18 years | 2.2 | 1.6 |
| Adults | 19 years and older | 2.3 | 1.8 |
| Pregnancy | All ages | N/A | 2.0 |
| Lactation | All ages | N/A | 2.6 |
