Make sure you get enough sunlight or take Vitamin D3 (along with a good multivitamin). I was taking 6000 IU at one point and it seemed to make a big difference since I was outside rarely. Taking 400 or whatever is supposedly recommended did not seem to affect me.

Although you might need to get a few blood tests if you are going to take a significant amount like that. If D level is not low at all then I guess you would not want to try that.

Ear plugs help me also.