Sir/Mam I am 25 years old. From last 1 year my eyes got weaken up, my hair got grey and I have issue of severe dry skin from birth in month of cold and I am not able to concentrate on studies, I feel my head heavy, brain fog ,not able to remember things for long time, feel tired always and when I go to bed I am not able to sleep also i feel short of breath. What could be cause of it. Is it due to B-12 deficiency (Because I am veg and I eat less dairy product) or starting of alzheimer .What to do in such situation. Please help.