I reckon you should be civil and polite - otherwise you may feel bad - but do absolutely nothing to encourage her.
By explaining, you are giving her reasons to argue with you. Just say 'no thank you' if you don't want her vitamins. Of course she may want to convince you ~ I might, myself, if I were her, but she has tried and you have refused and that's that.
If she argues, just say; 'No. really. I have already said no. Thank you.' And walk away. There is no need to be unpleasant about it, as long as you make yourself clear. Start a completely new conversation with someone else.
Don't invite her to your home; don't go to her home (unless this is part of the book club.)
Once she realises that you mean what you say, and you are not willing to listen to her spiel, she will probably leave the subject alone ~ and probably not invite you to dinner. Aah What a shame!
I do understand how you feel. I have been helped myself in this area. There are ways of keeping people at arm's length if you are having difficulties. It's just a matter of being polite but firm. You don't have to give her reasons. You don't have to pretend to like her. Often, it's just a case of reminding yourself of this.
That's what I think ~ I hope that it will help.
Last edited by PDM; 05/24/08 01:07 AM.