It is also needed for normal muscle and brain function, blood clotting, and DNA and RNA synthesis, and it activates the enzyme responsible for the formation of urea. Manganese may help with some symptoms of Parkinson's disease such as muscle rigidity and twitching, although an excessive level of manganese can in itself produce Parkinsonian syndrome from a loss of dopamine in the brain cells. L-dopa, which converts to dopamine in the brain, is used in the treatment of manganese toxicity to reduce the symptoms... Full Text