COQ10 and Vitamin E for Off-Target Radiation Toxicity

The goal of this supportive care study is to learn if high-dose Vitamin E and CoQ10 in combination can reduce the negative sub-acute and chronic side effects of radiation to the pelvis in adults treated for prostate, uterine, cervical, or anal cancer. The main questions it aims to answer are: * Is taking high doses of Vitamin E (dl-α-tocopherol acetate, 900mg) and CoQ10 (ubidecarenone, 200 mg) each day safe and tolerable? * Does a 90-day course of vitamin supplementation with high-dose Vitamin E and CoQ10 reduce the incidence and severity of late radiation-associated toxicities? * Does high-dose vitamin supplementation with Vitamin E and CoQ10 improve patient reported measure of quality of life? * Does high-dose vitamin supplementation with Vitamin E and CoQ10 change the trajectory of recovery after radiation therapy? * Is there evidence that suggests high-dose vitamin supplementation with Vitamin E and CoQ10 impairs oncologic outcomes? * Can longitudinal biomarkers of oxidative stress be correlated with Vitamin E and CoQ10 concentrations or radiation-associated toxicity? * Will subjects adhere to the vitamin administration schedule? * Are there demographic differences in systemic exposure to the vitamins? * Are there differences in toxicity outcomes across tumor types or radiation dose fractionation schemes? Participants will be asked to: * Take Vitamin E and CoQ10 every day for 90 days by mouth. * Fill out quality of life questionnaires to assess treatment impacts. * Come for clinic visits every 2-4 weeks for around 4 months, then every 3-6 months for around 2 years. * Have blood draws more frequently than standard-of-care for clinical laboratory examinations and the collection of research samples. * Undergo Computed Tomography (CT) imaging of the chest, abdomen, and pelvis more frequently than standard of care. * Agree to lifestyle changes that ensure adequate vitamin absorption including intermittent abstinence from alcoholic beverages.