Many of the neurologic disorders appear involve dysfunction in the mitochondrial energy-producing pathways. Among these are Huntington’s and Parkinson’s. There is some evidence that Alzheimer’s disease also has a mitochondrial pathology. Preliminary evidence is indicative of potential benefit of antioxidants nutrients, and clinical trials, supported by the National Institutes of Health, are currently underway to examine the efficacy of oral CoQ10 supplementation in both Huntington’s and Parkinson’s diseases. In these situations, both the coenzyme function of CoQ10 in energy production and its antioxidant function may be important.