My dog is about 16months old and 2 days ago she was laying on the ground and her head would start shaking back and forth and then stop and then start. Could this be series I've taken her to the vet so many times already because she's had skin problems. Could she be getting to many vitamins or not enough or could this be leading to a full body seizure and damage?? Please help

Baby, without being able to witness these incidents it is hard for anyone to diagnose what is happening on line. I know you mentioned you have brought your dog into the vet many times. Unfortunately, you will have to do so again. If your dog is having seizures, the vet needs to run tests and make an attempt to figure out what is going on. It may be something that can easily be remedied with the appropriate medication.

Yes, a vet needs to see her.

If she is eating a commercial dog chow and little else, she should be getting the vitamins she needs. If you are adding vitamins or other things, you could be doing more harm than good by upsetting the careful balance dog foods contain.