Supplements? No. I did as a kid, yes. Very very picky eater as a kid and needed them as I wouldn't eat many things that I needed to have nutritious diet.
My mom force fed me fruit and fish. :C
One day I discovered finely chopped carrots in my spaghetti sauce. I never trusted mom after that incident. D:
As a vegetarian, I try to take B12 vitamins daily. Especially since lately my hands have been itching a lot, which may be a sign of Palmoplantar Pruritus which can be caused by vitamin B12 deficiency. But I think it might also just be an allergic reaction to petting my roommate's corgi a lot...
No generally healthy person without major medical problems should take any kind of supplement. They are at best a waste of money and are likely even dangerous. All vitamins come in two categories. Fat soluble and water soluble.
The water soluble kind are harmless and in supplement form they barely even get absorbed at all and just come out in your urine. So yes you are literally pissing your money away.
The fat soluble kind are the dangerous kind. You will absorb them but with any first world diet you probably have all that you need. Since these vitamins usually come at high doses that means they your body will start storing them as mineral deposits in your joints and eyes. Yes minerals in your eyes. That is a pretty big health problem.
I do take Vitamin D supplements on occasion as my doctor tells me to because my digestion system is all kinds of messed up. I also have to get Vitamin B-12 shots on occasion despite them selling B-12 pills because they are the water soluble kind and injecting them into your fat is pretty much the only way to keep them in your system long enough to absorb them.
Unless you have an absolutely terrible diet, or have a medical condition that necessitates it (an actual diagnosed condition, none of this self-diagnosis bullshit) there should be absolutely no need for vitamin supplements. And if you do have an absolutely terrible diet, no amount of vitamin supplements are going to make you healthy and stop you from ending up in an early grave.
Sometime last summer I went to the doctor and my white blood cell count was low so he told me to start taking Vitamin D. I've been taking it every day since.
I didn't get out much at the time. It's a little less of a problem these days, maybe I could do without them, but whatever.
They probably aren't harmful, but to anyone whose diet consists of something more varied than bread and water, they absolutely aren't necessary (unless you've been diagnosed with a deficiency!). For the average person, they're a complete waste of money.
Like many people in this thread, I took those Flintstones vitamins as a kid, but I pretty much don't take anything as an adult now. Occasionally, when I feel like I should pretend I want to be healthy (although it seems vitamins are fairly useless?) I'll buy a bottle and take most of it before forgetting it exits.