The Food and Nutrition Board of the National Academy of Sciences has established a recommended daily allowance (RDA) or adequate intake (AI) for vitamins. The RDA or AI represents the minimum amount for each vitamin that we should obtain from our diet on a daily basis. The RDA is not a statement of the safety for any amount of vitamin. It simply suggests the MINIMUM you need to not become deficient in any certain vitamin or mineral.

Why then, if the RDA represents the bare minimum, do most articles and health professionals almost always say, “You should never take more than the RDA” or “Look for a multivitamin that supplies only the RDA”? In other words, “Do not take more than the bare minimum of any vitamin or mineral” is their recommendation. The implication is that taking more than this could be dangerous. The reality is that this concept is hogwash as the individual supplements found in a multivitamin have all been studied individually at doses much higher than the RDA without any significant or dangerous side-effects.

Also, it is important to consider that the RDA does not take into consideration many of the important factors that influence your true need for addition nutrients. These factors include disease states, how good or poor a diet you eat, your levels of stress, the number of children you have had, genetics, age, or whether you are male or female. For example, the RDA for a 4 year-old boy is the same as for a 25 year-old male/female or for a 50 year-old male/female. Does it really make any good sense that the RDA should be the basis relied upon for any sound nutritional advice? I think not.

My view is that anyone who would tell you that you should not take more than the RDA exposes their lack of knowledge in the field of supplementation. What they should say to you is “I really do not have any expertise in this field so it would be inappropriate for me to give you advice.” I think people would appreciate this type of honesty from their healthcare professionals. I know I would.

If you want to learn more about the RDA and vitamin quality listen to: The Vitamin Answer Book