High dose ordinary (nicotinic acid) Niacin causes a skin reaction called flushing. It's a rash that can feel warm and tingly in patches on your torso all the way to as painful as a bad sunburn all over your body. These doses cause your capillaries to dilate and releases histamine.
Over time our bodies do adjust to high dose Niacin with less severe flushing; starting with a low dose and slowly increasing is a way to avoid bad flushing.
In high doses Niacin behaves more like a medication than a vitamin. It is an effective treatment for lower triglycerides and has a lesser effect lowering LDL (bad) cholesterol and raising HDL (good) cholesterol. You shouldn't take high dose Niacin without physician supervision.
If you are taking high dose Niacin trying to beat a doping test than it probably doesn't work.
Niacin also means vitamin B3, nicotinic acid and vitamin PP.So they are vitamins and vitamins do not build a tolerance to your body but you do not need to take it many times because unnecessary vitamins goes out from the body without depotting {edit}
Niacin also means vitamin B3, nicotinic acid and vitamin PP.So they are vitamins and vitamins do not build a tolerance to your body but if you do not need to take it many times because unnecessary vitamins goes out from the body without depotting
You can 'overdose' on some vitamins (Vit A is one I think...) but not the B's because they are water soluable and you pee out any excess.