this is bullshit, m.d., entry 5
You know how you can build up a tolerance to alcohol or weed or whatever and need to take more for the same effect? Is that the same with vitamins?
No, because they're doing different things. Most vitamins are cofactors in chemical processes within your body, meaning that they help out the enzymes making the reaction.
For example, when you have a cut, you need some vitamin C to help rebuild collagen. If you don't have enough vitamin C, you can't make a collagen and so you can't heal your wounds. But more vitamin C doesn't mean you heal faster.
I guess like alcohol, you might require greater and greater amounts of a vitamin if your body is doing the reaction a lot more than normal, but that's rare. And also not the same mechanism.
Like people with tuberculosis often take a medication that can block vitamin B6, so a lot of times they take a B6 supplement. But again, not the same.
If you have too much of a water soluble vitamin, you can usually pee out the extra with no problems. Super high doses can be toxic, but again super rare and not from like taking an extra Flintstones vitamin. We store fat soluble vitamins so you can see toxicity maybe a little more from those, but those are usually from a naturopath prescribing like 50 vitamin E pills a day or someone eating polar bear liver (which have super high vitamin A concentrations).