Nutrition Science and Everyday Application - beta v 0.1

DEFINING NUTRIENT REQUIREMENTS: DIETARY REFERENCE INTAKES 45
a UL. However, if a nutrient does not have a UL, that doesn’t necessarily mean that it is safe
to consume in large amounts—only that there isn’t currently evidence that large amounts
will cause problems. Science is an ongoing process, and the toxicity of many nutrients hasn’t
yet been studied.
Putting It All Together
The graph below summarizes the meaning of the 4 DRI values for nutrient intake.
Figure 1.11. DRI values for nutrient intake. The EAR, RDA, AI, and UL are shown relative to the
observed level of intake and risk of inadequacy and adverse effects.
This graph shows the risks of nutrient inadequacy and nutrient excess as we move from
a low intake of a nutrient to a high intake. Starting on the left side of the graph, you can
see that when you have a very low intake of a nutrient, your risk of nutrient deficiency is
high. As your nutrient intake increases, the chances that you will be deficient in that nutrient
decrease. The point at which 50 percent of the population meets their nutrient needs is the
EAR, and the point at which 97 to 98 percent of the population meets their needs is the RDA.
The UL is the highest level at which you can consume a nutrient without it being too much.
As nutrient intake increases beyond the UL, the risk of health problems resulting from that
nutrient increases. The AI is shown to exist somewhere between the EAR and UL, as it’s an
amount of the nutrient known to maintain health.
Note that there is a wide margin between the RDA and UL, showing that a person might
safely eat much more than the RDA for a given nutrient without concerns of nutrient toxicity.
However, be aware that the margin of safety varies depending on the nutrient. For example,