Use of high doses above 1 gm per day of ascorbic acid or the derivatives thereof for the treatment of neurodegenerative and neuro- muscular degenerative diseases and disorders, in particular amytrophic lateral sclerosis (ALS), multiple sclerosis (MS), alzheimer's disease (AD), parkinson's disease (PD), and muscular dystrophy (MD) is disclosed. Preferably the dose comprises mannitol which facilitates the delivery of ascorbic acid to the target cells in the brain. Still further the said dose comprises zinc citrate for preventing formation of kidney stones. Dose compositions for various routes of application such as oral, intravenous, intramuscular, nasal and in the form of transdermal patches are discussed.