I certainly had this for 7 or 8 months- in my case it affected my nervous system- chronic pins and needles in feet, internal buzzing/tremor sensation , trouble with light or noise , a bit of vertigo - and headaches. It has eventually all calmed down with the help of low dose beta blockers, masses of water and vitamins , light stretching and calm deep breathing- but left me with a bit of arthritis in my neck- that could be coincidental though as I'm 62- I do still tire easily and my brain isn't quite as sharp -only bonus was the amount of tests I had - was like a good MOT and picked up my pre diabetes, slightly low Vit D and cholesterol too high. I've lost several stones with a few more to go too. Went gluten free and I think that helped - my turning point was spraying b12 under tongue- my active b12 levels showed as totally fine- but the minute I used the B12 spray the pins and needles improved radically, as did the headaches.