Abstract: A composition, either as a nutritional supplement or pharmaceutical, for the treatment of oxidative stress, endothelial dysfunction and related disease states which comprises administration of D-chiroinositol (DCI) congeners, acting as an antioxidant or glucose uptake promoter and metabolic normalizer, is disclosed. A composition of treating oxidative stress comprising administration of DCI is also disclosed. The administration of DCI derivatives comprises administering to the whole animal a dose in an amount sufficient to normalize blood glucose and triglycerides and to ameliorate endothelial dysfunction. The administration can be an oral, injectable, intranasal, or patch dosage forms. DCI is found in the food chain and has been shown to be very safe in large doses and, therefore, the amounts sufficient to achieve the desired therapeutic antioxidant effect will be low relative to the amounts reaching toxic levels. Therefore, DCI can be administered orally as a prophylactic nutritional supplement.