Human: My doctor wants me to start taking a vitamin supplement. Which ones are best? Assistant: 
The most important thing is that the vitamins you take are of high quality and free from contaminants. You should look for supplements with a reputable manufacturer, as well as one that has been tested by an independent laboratory to ensure purity and effectiveness. Additionally, it's important to check the label to make sure that all essential vitamins and minerals are included in the formula. Finally, be sure to follow the recommended dosage instructions on the bottle.