I've also read recently about Vitamin A's potential benefits, particularly for ETD.
It certainly helped this person, she also used some Zinc and a small amount of Copper. http://patient.info/forums/discuss/cured-my-eustachian-tube-dysfunction-498607
I've just bought some Dry Vitamin A, and will take a tablet daily (5000IU).
If no real change, I will up my intake and report back here if I notice any improvement in my symptoms.