Manganese is another important trace element. It is mainly involved in the nervous system and allows for the normal functioning of the brain, the treatment of some nervous disorders, promotes nerve function, and promotes normal growth and development. Some other functions includes working with vitamin K to promote blood clotting, acting as an antioxidant, helping various enzymes to generate energy, metabolizing energy, producing melanin, producing urea, synthesizing fats, aiding in carbohydrate metabolism, and aiding in the formation of connective tissue
Plant sources of manganese include cereals, whole wheat bread, bran, buckwheat, root vegetables, green leaf vegetables, dried beans, blueberries, blackberries, peas, chestnuts, hazelnuts, and peanuts. Animal sources include liver.
Absorption of manganese is less efficient when accompanied by calcium, iron, and phytate. Deficiency is rare as manganese is readily available in many foods. However, symptoms include retarded growth, abnormal bone and cartilage development, problems metabolizing carbohydrates, muscle weakness, fatigue, fragile bones, and blood-sugar problems.