When you use heat to cook your food (grill, fry, bake), the heating process removes some of your food's beneficial nutrients. In addition, if you are plagued with stress or you if you are taking medication there's a chance that you are losing a significant amount of vitamins and minerals that you consume. Taking vitamins on a regular basis can increase your chances of getting all the nutrients your body needs.
The benefits of taking vitamins go beyond meeting the recommended dietary allowances. How healthy you are depends on more than just diet and the amount of exercise you obtain. There are other outside factors that can predispose you to develop certain health issues. For example, how much of a risk you have for developing cancer of heart disease is largely dependent upon whether or not others in your family developed these conditions. For some time it was believed that an individual had very little recourse in these situations. Studies conducted by Harvard University researchers revealed that taking a multivitamin every day can reduce an individual's risk to develop these conditions.
To determine your specific needs, you should visit your doctor for a complete evaluation of your dietary needs. Your doctor will be able to recommend the type of vitamins that are best for you. It may very well be the case that a common multivitamin is all that you need. If this is the case, you can visit any nutrition center or grocery store and find aisles of multivitamins. While these preparations will contain the same basic set of vitamins, the amount of each will differ. You can determine which preparation is for you by considering which nutrients you lack. For example, if you're not a fan of milk products, you may want to choose a multivitamin that contains more calcium.