Have you ever thought that understanding nutrition can be a little overwhelming? There’s so much information out there, and oftentimes, what you read or hear one place is contradicted with something you read or hear another place.
One resource you might have turned to for information on essential nutrients is the Food and Nutrition Board of the Institute of Medicine at the National Academy of Sciences, which monitors the health of Americans and establishes Recommended Dietary Allowances (RDAs) based on developing scientific research. But despite the rigorous data behind these recommendations, these “official” guidelines have some caveats.
About the RDAs
RDAs vary by age, gender, and whether a woman is pregnant or breastfeeding. RDAs are a subcategory of Dietary Reference Intakes (DRIs), which represent the average amount of essential nutrients demonstrated to maintain general health in most individuals. DRIs include RDAs, Estimated Average Requirements (EARs), Adequate Intake (AI) levels, and Tolerable Upper Limits (TULs), which can vary by age, gender, and for pregnant and lactating women.
RDA’s represent values backed by the most substantial evidence, and are therefore used to inform the Percent Daily Values (% DV) on Nutrition Facts or Supplement Facts labels. In order to qualify as an RDA, the quantity of a nutrient has been shown to support daily wellness in 97-98% of healthy people in a particular category. Sounds pretty precise, right? Well along with the 2-3% of outliers in that population, shifting science and empirical evidence have called many of these numbers into question.
Why the Recommended Dietary Allowance May Not Be Reliable
While RDAs are generally a good guide, there are a number of reasons to give them a second glance:
The amounts are intended to provide “adequate nutrition”, not necessarily to promote optimal health
To understand this point, it’s helpful to understand how and why the RDAs were established. The body that developed the RDAs, the Food and Nutrition Board (FNB), was established in 1940 during WWII to advise the Army on guidelines for good nutrition. The FNB realized the need to develop recommendations for nutritional intake for both the general public and the armed forces and introduced the RDAs the following year in 1941.
The goal of the FNB was to estimate the amount of a nutrient necessary per day for the maintenance of “good health.” At the time, the term “good health” referred to the minimum intakes required to avert nutritional deficiency diseases, such as scurvy, a condition caused by too little vitamin C, or rickets, caused by too little vitamin D.
However, in many cases, research has shown that these minimum amounts are far lower than optimal amounts that are fully supportive of good health. There is a big difference between the amount of Vitamin C needed to prevent scurvy during a time of scarcity, and the amount needed for an optimally functioning immune system in the global society of the 21st century.
It’s worth noting that the FNB does revise the RDAs every five to ten years based on advances in research and scientific understanding. For example, they added an RDA for choline in 1998. However, many believe that they still have not kept pace with current research on optimal levels vs. minimum requirements.
The amounts group all adults into the same recommendations
While the RDAs do account for age group and gender, they were originally set using data from adult men in the 1940s and then simply adjusted to account for different biological differences due to age, sex, and pregnancy or breastfeeding status. Unfortunately, RDAs don’t account for many other variables that exist within these groups, like activity level, health status, or other medical conditions.
The recommendations don’t consider the interaction of other nutrients
Many nutrients either require another nutrient to be fully absorbed or used in the body, or can interfere with the absorption of another nutrient. For example, your body needs vitamin K to properly absorb and use vitamin D. On the other hand, when you consume or supplement with iron, it can restrict the absorption of nutrients like calcium and zinc.
Not every nutrient shown to support good health has a Recommended Dietary Allowance
Even with an extensive list of RDAs, there are still many indispensable vitamins and minerals without any set reference intakes. This can be the case with nutrients like vitamin K2, which is not factored into the scientific basis for vitamin K needs. The current AI level for vitamin K lumps K2 with vitamin K1, but they have distinct functions and health benefits. In addition, there’s no official RDA for the Omega-3 fatty acids DHA and EPA despite tremendous research on their importance for optimal health at all stages of life.
So What’s the best way to use the RDAs?
- Use these numbers as a guide not gospel: These numbers are a good guide to start, but don’t put all your trust into them. Scanning a food or supplement’s label and seeing that 100% of the Daily Value for a nutrient is provided can give you false comfort, as it may be less than what you actually need. Similarly, seeing a larger percentage in the DV column might make you wary that you’re getting far too much, when it is actually an optimal amount. That’s why we always recommend consulting with your healthcare provider about any supplements you are taking to ensure you’re taking the right amount for your body and stage in life.
- Note gaps in your diet: If you avoid an entire food group or class of foods, chances are that you could be missing out on some nutrients. These are areas in which you might consider a supplement to fill gaps. For example, if you don’t eat meat, you are more likely to be deficient in nutrients found primarily (or primarily in their active forms) in animal products, like iron and B vitamins. Since most of us don’t even a perfect diet all the time, most experts recommend a high-quality, balanced multivitamin and mineral formula for just about everyone.
- Don’t overlook the “non-essentials”: RDAs focus on the major vitamins and minerals that your body uses to support the major structures and functions in your body. But a multitude of evidence highlights the critical importance of plant phytonutrients that work alongside and uphold these essential nutrients. The potent antioxidants in fruits, vegetables, and botanicals might be the key to truly optimal health. Since you may not have access to fresh, micronutrient-rich produce year-round, a whole food supplement like Berry Power or Pure Synergy Superfood could be a perfect way to help you eat the rainbow.
Nutrition Isn’t One Size Fits All
Ultimately, health and nutrition isn’t one size fits all. Each individual is unique, and there might not be a set of guidelines that works for every individual. Instead, use the RDAs as a guide, listen to your body, talk to your doctor, and take the supplements that help you feel good and stay well.
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