What does Recommended Daily Intake (RDI) mean?

Janis Jibrin, MS, RD
Nutrition & Dietetics
I’ll explain RDI -- a Food and Drug Administration (FDA) term -- but first I’ll offer some background and context so you can better understand this term. (Which, as you’ll see, isn’t a term that means much to anyone!)

Get ready to get into the weeds of FDA terminology. I’ll try to make it as painless as possible:

First, some background: The Institute of Medicine sets DRI -- Dietary Reference Intakes (not to be confused with RDIs -- the term you asked about). DRIs include the RDA’s (Recommended Dietary Allowances) for vitamins, minerals, and “macronutrients” (which are carbohydrates, fat, protein, fiber, etc.) for each age group and gender. These are the levels of each nutrient that should meet the needs of people in these various age/gender groups. For example, the RDA for iron for women age 19–50 is 18 mg -- on the high side, because women of that age lose iron in their monthly periods.  But the RDA for iron is just 8 mg for women age 51 and older because most women are post-menopausal at this point. It’s also 8 mg for men age 19 and older. (And it changes again for infants, children and pregnant women.)

As you can imagine, putting all the various RDAs for each age group and gender on a food label would be impractical! To get around this, the FDA chose just one RDA value for each vitamin and mineral and called it the “Daily Value." Look at a food label and you’ll see “percent daily value” for nearly all the nutrients listed.

How did the FDA choose the daily values? Often, they chose the highest RDA for each nutrient, thinking that would cover nearly all the population. Going back to our iron example, the Daily Value for iron is 18 mg.  

Here’s where the RDI comes in. It stands for “Reference Daily Intake." It’s basically that one RDA value the FDA decided to use to create the Daily Values.  

So, really, you don’t need to worry about the RDI. When you look at a food label, check out the percent Daily Value, realizing that it may not perfectly apply to you. For example, the label on my jar of peanut butter tells me there’s 4% the Daily Value of iron in 2 tablespoons. At 18 mg, the Daily Value for iron is right on target for a woman age 19-50, but doesn’t match anyone else. That’s okay, at least I know there’s some iron in my peanut butter. And, for example, I can use the daily value to compare labels of different brands of yogurt to see which has more calcium. Likewise, I can tell if a food is high or low in saturated fat, or other nutrients.

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Important: This content reflects information from various individuals and organizations and may offer alternative or opposing points of view. It should not be used for medical advice, diagnosis or treatment. As always, you should consult with your healthcare provider about your specific health needs.