second chemo treatment second time...

I just want to know if anyone has experience with the following: I have had two chemo treatments and both times my white blood counts have fallen low were they have to delay treatment by a week. They are fine with a week off. The docs tried to reduce the amount of gemzar I am getting to 80% but my whites dropped again. They are going to reduce the amount again but they are stumped as to why it is affecting my bone marrow like it is. Has anyone had this experience and if so what did they do. Is there any vitamin I should be taking to help my white blood count. My body reacts so abnormally that I am thinking I should leave it to science.