Hello, and thank you for your post.

I am sorry to hear that your dad is due to start radiotherapy for prostate cancer. I can appreciate you asking about the safety of taking Co Enzyme 10 supplements.

Although we can't be sure if it is safe to take this while having radiotherapy, there has been some concern about it. This is because it is a type of antioxidant, which could interfere with how the radiotherapy works. We have information about vitamins and diet supplements on our website, which would be useful to read. Scroll down to Side Effects, where you will see antioxidant information.

I hope this has been of some help.

Please do get back to us if you have any more questions. You can call us free on our Helpline 0808 800 4040. We are here Monday to Friday 9-5 (excluding Bank Holidays) 

Take care,