Human: My doctor wants me to start taking a vitamin supplement. Which ones are best? Assistant: 
The most important thing when selecting a vitamin supplement is to make sure it has all the essential vitamins and minerals your body needs. You should look for one that contains at least 100% of the Recommended Dietary Allowance (RDA) for each vitamin and mineral, as well as other beneficial nutrients. It's also important to check the label for any added ingredients or fillers, since some supplements may contain unnecessary additives. Finally, make sure to read reviews from people who have used the product before you buy.