Too Much Of A Good Thing: RDA and TUI

(Originally posted on bcotoronto.com on July 26th, 2012)

Calcium BottleThe problem that many people have with nutrition is the idea of quantity. I’m not talking about counting carbs or portion control but doses of nutrients like vitamins and minerals. There seems to be a lot of confusion around just how much of these things we need in our diets. Health classes in high school and some doctors tell us one thing but this differs from what we hear in the media and from other doctors. So what are we to believe? This week I would like to show you where this difference comes from and what it all means.

In the 1940s the governments of many countries compiled and published nutritional recommendations. These have seen a couple of different updates and modernizations over the years but they have remained relatively unchanged in their basics. These recommendations are what developed into the Four Food Groups and the Food Pyramid and more recently “My Plate”. But there is a side to this nutritional guidance that is more detailed than “Eat 4-6 Servings a Day”. This is simply the RDA and the TUI of each nutrient we need.

The RDA/RDI is the “Recommended Daily Amount/Intake” which means it is amount that you need to absorb every day to stay healthy. The TUI is the “Tolerable Upper Intake” which means it is the amount of the substance where it begins to overload our systems and cause side effects and sometimes even become toxic. But there is a range in there that for some nutrients like Vitamins C and D is quite large. So what does this mean for health? Do we only need the RDA and everything over that is just pushed through out systems, unused until its excreted? Well, this is where the confusion comes in.

The RDA for all nutrients is set at the absolute minimum possible amount we need to stave off a deficiency and this is what we are taught in school. This only supports the most basic processes of life and does not allow for any spare wiggle room for unexpected challenges in our lives and, as you know, with the standard North American lifestyle and diet there are a great many challenges that our bodies face every day. From pollution to potato chips we are assaulted from all sides by chemicals and toxins that would damage our tissues. So if we are taking in enough of the nutrients we need to just get by with the very basic processes that keep us going then all that damage will accumulate and lead to disease and dysfunction.

The TUI is the upper limit of this range of healthy nutrient intake and has remained the same for the minerals for a very long time but for the vitamins it seems to be ever changing. This has been especially true with Vitamin D which has had its TUI increased twice in the last decade. So with this in mind we should all be exceeding our RDA of nutrients and my recommendation is to get your vitamins as close to the TUI as you can (without passing it. They are there for a reason) and your minerals somewhere in the middle of the range as they have the greater potential to actually cause harm. This load of good nutrients will prime our systems to be ready to fight off and repair anything that challenges us throughout our day.

The other part of the confusion around this issue is our inability to accurately determine exactly how much of these nutrients we are getting from our diets. We are very good at counting the calories in our diets but who really knows how much Selenium they are getting? This is why I and many other natural healthcare practitioners promote a Whole Food diet that eliminates processed foods and replaces them with a wide variety of organic and fresh foods. A diet like this will give us a good amount of everything we need to get by and more.

The Standard North American Diet (SAD) is filled with tonnes of processed and “fake” foods that might taste good but have little nutritious value. This brings many of us close to or even below the RDA for many minerals and vitamins which are found in the largest quantities in fresh vegetables, especially those dark green leafies that are so lacking. So if we are below the RDA then is it really that surprising that our bodies are breaking down and we have so many conditions like heart disease, Type II Diabetes, and obesity which are being referred to as “Western Diseases”?

Supplementation may be used to increase the intake of any mineral or vitamin if necessary but natural food sources are much better. The come packaged in the same environment we evolved to find them in. Quality really helps to get the most out of them.

Thanks for reading and eat your green leafies,
Dr. Ben

For anyone interested in the current (as of July 26th, 2012) RDA and TUI values according to Health Canada follow the links below:
Vitamins
http://www.hc-sc.gc.ca/fn-an/nutrition/reference/table/ref_vitam_tbl-eng.php

Minerals
http://www.hc-sc.gc.ca/fn-an/nutrition/reference/table/ref_elements_tbl-eng.php

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