How often have you reached for that first cup of coffee in the morning to perk you up? If that's part of your daily ritual, you are not alone. Did you know that caffeine is one of the most commonly used drugs in the world? A huge number of people around the world use caffeine in some form daily. The main dietary sources of caffeine are coffee, tea and soft drinks, but remember that caffeine can also be found in chocolate and in some medicines.

It's also important to remember that caffeine has no nutritional value and, in some instances, people with certain health concerns will be advised to limit caffeine or eliminate it from their diet. You may want to reduce your intake of caffeine gradually to prevent caffeine withdrawal symptoms (headache, fatigue, or drowsiness) from occurring.

A 5-ounce cup of coffee averages 100 milligrams of caffeine. Here are some other sources of caffeine to watch out for:

  • Vivarin (1 tablet), 200 mg
  • Excedrin (1 tablet), 65 mg
  • Unsweetened baking chocolate (1 ounce), 57 mg
  • Iced tea (12 ounces), 30 mg
  • Diet Coke (12 ounces), 46.5 mg
  • Coffee ice cream (4 ounces), 24 mg