It’s a question I have been asked numerous times before, “Why do I need to eat a bunch of fruits and vegetables when I can just take a multivitamin everyday?” The answer: fruits and vegetables contain an incomparable nutrition package. They contain nutrients we are only just beginning to discover and understand, such as phytochemicals and other antioxidants. And, they contain these elements in perfectly proportioned amounts, that our bodies have evolved to absorb and utilize optimally. Vitamins, on the other hand, contain large amounts of relatively few nutrients, most of which will leave our bodies unabsorbed.
I am a big advocate of getting as much of your nutritional needs as possible from food. Personally, at this stage of my life, I do not take any vitamin supplements. I eat a balanced diet, and I feel confident that I’m getting everything my body needs from my food. Vitamin supplements are no excuse for a poor diet! That said, there are certain people that may benefit from taking vitamins. Women who are pregnant, or who might become pregnant, may likely benefit from a prenatal vitamin. Elderly people and very petite women who have lower calorie requirements may find it difficult to obtain all the nutrients they need from their food, and may benefit from a daily multivitamin. Young girls who are lactose intolerant or do not consume much dairy may benefit from a calcium supplement to ensure they reach their peak bone mass. (These are just some examples. If you are unsure about your own vitamin/mineral needs, talk to your doctor.)
Additionally, some vitamins have toxic upper levels that you d
o not want to surpass by taking vitamins. In particular, fat soluble vitamins (Vitamins A,D,E and K) have toxic upper limits. If you are taking mega-doses of any of these vitamins, you may want to reconsider. Also, don’t forget that many foods these days are fortified with vitamins (breakfast cereals, power bars, weight loss shakes, etc.), so be sure to factor those into your count.
So, to sum it up: Get your vitamins from your food first! Then supplement if you still need to, but don’t overdo it.
Nicole Geurin, MPH, RD 
I’ve had this conversation with a lot of friends! Also about Total Cereal… why should they eat healthy all day if they have a supplement or a “complete” cereal already? Uh, because it’s good for you.
Personally, I’m anemic, but rather than taking just an iron supplement, I take a prenatal vitamin, as I want to prepare my body to have children in the next few years. I still get lots of important nutrients from my food, though. It’s not smart to rely solely on the supplement!
Great post! I’ve gotten this question before too.
Great article, i think this is a question a lot of people are interested in and i’m so glad you wrote about it, you made really great points!