It's about dang time we talk about vitamins! Many people take them, not everyone needs them. There is skepticism in the health industry that every individual needs to take a daily multivitamin. What I have learned from this is 1. Good multivitamins are generally quite expensive 2. They don't make those awesome gummy vitamins for adults and 3. If I take a multivitamin, I'm getting about three times the amount of specific nutrients than I actually need. So do some research and save some green!
Levels of vitamins and nutrients differ among every individual. Each person does not need to sustain the set level that you see on food labels-- much like how not everyone needs a full 2000 calorie diet. The most important thing you need to do is track what nutrients you get the least of and make up for it. The best way to absorb vitamins is through food, not a pill. Change your diet to include what you are lacking. If this is for some reason impossible, then taking vitamins is your back up plan.
If you DO need to take vitamins, I would suggest figuring out exactly what you are lacking and take only that. Sustaining high levels of other vitamins is useless to your body because you will just pee it out, and in some cases, too much of one nutrient can be harmful. Pay attention to how your body reacts to vitamins and food. Track what you eat and track your energy levels. This is the best way to figure out what your body needs.
I take B-Complex, for energy metabolism (I don't process food very well or get much energy from it) Iron, for proper erythrocyte function (when I'm at home, my parents are weekday vegetarians, at school I only eat chicken and fish- hence little iron) and St. John's Wort (this is an herbal supplement, not a vitamin)
The latter is literally a happy pill. It was used early in the 1900's as a treatment for depression (which proved effective) but when the FDA was formed, they decided to not extensively research it. Now the label says 'Promotes a Positive Mood'-- and it really does. It is believed to inhibit the reuptake of seratonin, (to biology and psychology savvy people, it acts like an SSRI) therefore increasing the levels of seratonin in the synaptic cleft, allowing more to be absorbed by the postsynaptic neuron. Long story short, it doesn't increase levels of seratonin, it just increases availability and seratonin = emotionally, environmentally conscious and happy. Life is SO much easier when you're in a positive mood, so if you are chronically effected by your own negativity, I recommend this supplement.