OMG I just did some quick research into 160B and it acutally says it causes headbanging in small children A LOT of different sources say this - I can't believe it is so widely used if this is such a common reaction

Thanks again salad for bringing this to my attention - I never would have thought of this as a possible cause
Wow ...thanks for sharing this.

My DS1 used to head bang and hit himself all the time too....I think it lasted a few months (around a similar age as your DD). I use to worry as quite often it would leave little bruises (and I would just hope his child care workers and any body else who saw this understood it was a self inflicted injury). Thankfully he grew out of it....once he learnt to communicate better.

I try adjust his food - which could be tricky if it turns out to be common in alot of things (though he does eat alot of fruits and vegies...but sadly grapes are a favourite too )....and watch for this additive (which I never knew about)...and hopefully I can eliminate the squealing - which is not as bad, but very ear piercing I also have an almost 1 year old, who is possibly likely to go down the same path of frustration communication.