Headaches!

For the past couple of days I've been having headaches and light headedness! My blood pressure is normal and I'm trying to keep hydrated.  But something is going on where just these 2 days I'm all of a sudden having this problem.

Has anyone else gone through this or going through it now?

I don't get headaches very often anymore.  But I did start to experience dizziness every so often this summer.  I've pinned mine down to allergies.  My OTC allergy med (loratidine) doesn't help with it either.  It helps with the stuffy nose and stuff, but not the dizziness.  I'd only experience that if I stood up, sat down, turned around-something that would move my head too fast.

 Vitamin D supplements give me headaches.  My D level is a tad low, even when I take 1000 mg a day.  So I started taking 2000 mg a day, and BAM - vicious headaches that wouldn't go away.  I looked up vitamin D toxicity, and that's one of the main side effects.  So if you just upped your D intake, that could be it.  Make sure you're getting enough liquids, too, because dehydration causes headaches, as well.