Multiple Sclerosis (MS) patients present a decrease of antioxidants and neuroprotective and immunoregulatory vitamins and an increase of total homocysteine (tHcy), cholesterol (CHL), HDL-cholesterol, and of cellular stress markers, variably associated with the different phases of the disease. We compared the blood levels of uric acid, folic acid, vitamins B12, A, and E, tHcy, CHL, HDL-cholesterol, and triglycerides in forty MS patients during a phase of clinical inactivity with those of eighty healthy controls, matched for age and sex. We found higher levels of tHcy (p = 0.032) and of HDL-cholesterol (p = 0.001) and lower levels of vitamin E (p = 0.001) and the ratio vitamin E/CHL (p = 0.001) in MS patients. In conclusion, modifications of some biochemical markers of cell damage were detected in MS patients during a phase of clinical inactivity.