Is taking vitamins and minerals in quantities greater than the Recommended Dietary Allowance (RDA) unsafe?
A. No. Most vitamins and some minerals are safe at levels many times greater than the RDA. The RDA is the level of intake recommended to maintain health, and is not in any way a safety limit. In fact, for many nutrients, for example vitamins D and E, scientific research suggests potential benefits can be gained by intakes beyond the RDA. The same experts that establish the RDA also set Upper Levels of Tolerable Intake (UL). The UL is also not a safety limit, but simply identifies a level of daily intake at which there is no known toxicity, and at which there is sufficient evidence of safety for the nutrient. The UL neither suggests that intakes above that level are unsafe, nor does it constitute a recommended intake. For some vitamins, like C and E, the UL is more than 10 times higher than the RDA. In some cases there is no UL as is the case for some B vitamins. This is because no study has ever identified an unsafe level, even when large amounts have been given.
