Elderly Parent as Deduction - is there more than default amount?

Hello, 

 

I am claiming an elderly parent that does not live with me.  She has no income but does get social security that does not cover all of her rent or over the counter medicines, etc. I saw that claiming her as a deduction gave me $500.00.  Would itemizing each monthly expense I pay for her (about $600.00 per month) be a possibility to give me more of a refund or is the most I could get be the $500.00?  Thank you