you can add some to your drinking water but I am not sure what you would gain. I used to work with a lady who did that. I asked her why, she said it helped to keep your body slightly acid and that was good.
A - you are taking 5% acid vinegar, diluting it with water, and putting it in your stomach which is already extremely acid.(PH of about 1).
B- your body knows and controls how acid/alkaline it should be, if you could change it significantly, you would DIE. Look up acidosis.
I did not tell her any of this, my theory is, don't tell anyone something they don't want to hear.