I think most multi vitamins will NOT hurt you..I think where you can get in trouble is high dosing of certain vitamins and minerals ( and foods) ...Key Vitamins and Minerals to Avoid or Limit:
Vitamin E (Alpha-tocopherol): Daily doses greater than 400 IU are strongly discouraged, as they are associated with an increased risk of cancer progression.
Selenium: Studies indicate that high-dose selenium (e.g., 140 micrograms/day) can potentially increase the risk of dying from prostate cancer and has been linked to a 91% increase in high-grade cancer.
High-Dose Zinc: Long-term use of high-dose zinc supplements (often found in multivitamins) is associated with a higher risk of developing prostate cancer.
High-Dose Multivitamins: While regular, low-dose multivitamins may not be harmful, high-dose supplements should be avoided unless specified by a doctor.
Calcium: Excessively high total calcium intake (largely from supplements) has been linked with an increased risk of advanced prostate cancer.

It is generally recommended that men with prostate cancer avoid high-dose supplements unless they have a validated deficiency, as they offer no clear benefit and pose significant risks. Always consult with your oncologist before starting any supplement.

Last year, I was eating ALOT of high fat cottage cheese and honey which I love...and guess what, high fat dairy products should be avoided by older men because they are linked to prostate cancer progression...yep..and I ate ALOT thinking the calcium and ppprotein were good for me.