Is it OK to give Sr citizen prenatal vitamins?

Other option better. No harm in it, really, but a prenatal vitamin may not contain the amount of other vitamins and minerals (like calcium and vitamin d) recommended for this age. A multivitamin specifically formulated for older men or women would be a better option. .
Yes and no. Prenatal vitamins containing various essential nutrients for the development of the fetus, especially Folic acid, and other B complex vitamins, which are important for the development of the neural tube at the first trimester of pregnancy. However, the nutritional needs and requirements of elderly patients a different from that of woman of childbearing age, which may not be appropriate.
Vitamins. Yes, senior citizens can take Prenatal Vitamins. Be careful of the Iron content in those vitamins as they can cause upset stomach and even constipation. Check with their doctor with regards to the contents in the vitamins to make sure there are no interaction with other medications that they may be taking (Vitamin K can affect Coumadin)