Vitamins and Antioxidants
Are they effective?
If you are reading this page, it implies that your computer is connected to the internet. Consequently, you can't have missed being bombarded with a plethora of advertisements suggesting you take vitamins and antioxidants that will extend your longevity, prevent heart disease and cancer, make your skin younger and smoother, improve your memory, and a myriad of other claims we all wish were true. In this series, we will try to determine the facts - what claims are true, what benefits can we expect from vitamins and antioxidants.
Last Modification - Epilogue Updated, May 22, 2009
It is believed that cell damage, caused by "free radicals" that are formed form when oxygen is metabolized or burned by the body, contributes to aging and various health problems. These free radicals travel through cells, disrupt the structure of other molecules, and cause cellular damage. It is though that antioxidants may protect key cell components by neutralizing the damaging effects of the free radicals that result from cell metabolism.
Vitamins are essential chemicals that the body needs in small quantities to stay healthy. Vitamin C is one of many needed vitamins - it prevents scurvy (resulting in lack of energy, gum inflammation, tooth decay and bleeding problems). Each vitamin has a "recommended daily allowance" (RDA) that is sufficient to prevent disease. The Vitamin C RDA for adults is 90 milligrams for men, and 75 milligrams for women. Most North American adults get enough Vitamin C in their regular diet. Several vitamins, notably E, C and beta carotene (a form of vitamin A), are also antioxidants.
It has been demonstrated that a diet rich in fruit and vegetables provides health benefits (please see our summary for more details). Are the benefits due to vitamins? i.e., can one substitute vitamin pills for a diet rich in fruit and vegetables? The complete answer lies in the fact that fruit and vegetables contain a multitude of chemicals (phytochemicals - chemicals in plants that may affect health, but are not considered essential). It is not known which, or what group (if any) of phytochemicals produces these benefits.
Many people take multivitamin supplements daily, even though they eat healthy diets that provide them with RDA's of vitamins that are sufficent to prevent the known diseases associated with vitamin defficiency. Some even take much larger doses of vitamins, that exceed the RDA's by a factor of 10 or more, expecting them to have a protective effect against a variety of illnesses. Is there any evidence to support this approach? We will examine the research relevant to this question in the following pages.