Manganese is a mineral salt that is found in several foods including nuts, legumes, seeds, tea, whole grains, and leafy green vegetables. It is considered an essential nutrient, because the body requires it to function properly. Manganese is used for prevention and treatment of manganese deficiency, a condition in which the body doesn’t have enough manganese. It is also used for weak bones (osteoporosis), a type of “tired blood” (anemia), and symptoms of premenstrual syndrome (PMS). Manganese is sometimes included with chondroitin sulfate and glucosamine hydrochloride in multi-ingredient products promoted for osteoarthritis.