It might be this brand of multivitamin that's bothering you, if that's what it is. Stop taking them, and if what's bothering goes away you'll know it's the vitamin. Of course, it's always better to get your nutrients from foods, but a multivitamin, if it's a good one, is a good idea for most. At your age you probably don't need one with much potency, but our food supply today almost guarantees some deficiencies. The food is grown far away, meaning it takes time to get to the store and more time to get to us, and with the passage of time nutrients disappear. If you're not buying organically grown food, the soil the food is grown in isn't nutrient rich, so you might lose something there. If you're preparing foods in ways that destroy some of their value, you're losing things. A multivitamin is a prophylactic to just supplement a bit your diet, but it has to be a good vitamin that is well absorbed and well formulated. You also want to make sure any supplements you take don't have additives that are toxic or interfere with absorption, which most inexpensive vitamins have in them. Some of these additives could be causing you problems as well.
@bromad - First, if you are having an unexpected side effect to any supplement, you should discontinue use immediately and have a conversation with your doctor about what could be going on.
If you decide to discontinue use, see if the twitching goes away. I'm not sure what you mean by "vibrating like feeling".
Twitching can sometimes be caused by "benign fasciculation syndrome". I get it from time to time in various parts of my body: eyelids, arms, legs, etc. I spoke to my GP about it, who referred me to a neurologist, who ultimately gave this BFS diagnosis after ruling out other causes.
On my own reading, I noted that diet can sometimes influence the twitching. In particular, magnesium seemed to be mentioned often. Make sure that your diet is well-balanced despite the multivitamin; remember, it is a supplement to, not a replacement of, a normal diet.
If your doctor gives you the go-ahead and rules out any other causes for the reaction, you can discuss trying another brand of multivitamin. That said, do your homework; multivitamins are very controversial. It's worth spending some time reading about different types of MVs, the cases for and against them, and finally considering the reviews of particular brands.
Yours in good health.