Toothpaste?

So what do you do with a 2o month old munchkin who loves to eat toothpaste?  Yes, she finds the tube and walks around sucking the end of it.  Gross!  I hind them, she finds them!  I hate to admit that my child eats toothpaste.  I am questioning if she is deficient in some mineral or something.  I know that if you have the desire to eat dirt or rocks that you are low in certain minerals.  Crazy I know, but this is my crazy life day in and day out.