For the past few months I've been feeling fatigue, dizziness, a feeling of fainting. This happens throughout the day thereby affecting my productivity at work. I've visited multiple doctors for but everything was normal. But the issue hasn't been resolved yet. As i travel a lot on my bike I thought to check if there's any back/spine related issues but they too seemed normal. I also had my ears checked to an ENT specialist regarding infection/vertigo (BPPV) but found nothing. Also visited a cardiologist but no luck. Can any type of
vitamin deficiency cause such an issue? If yes then what type of blood tests should i conduct before consulting a doctor.