Dizzy af!

I recently started working out, and I’ve noticed that I am more prone to dizzy spells now. Like when standing up after sitting (this hasn’t been an issue for a while for me) or even just at rest. I can’t pin point any other change in behavior that could trigger this. I had this problem when I was younger but it was due to a vitamin deficiency that I ended up dealing with. Any theories and maybe self care treatments? I also have a history of low blood pressure but it hasn’t been bugging me until I started working out but I haven’t taken a reading yet.