Recommended Nutrient Intake


“I am looking for “naturopaths’ advice” on vitamins and minerals levels -zinc, magnesium, calcium, chromium, iron, B12, D, C etc. I know the GPs recommended levels, which are not the optimum levels, I would like to know where I can find the “real” levels we actually need.”


GP’s recommended nutrient levels, so long as the GP in question is staying up to date with changes, are generally coming from the best research available at the time. You can access this information via government websites such as this:

As you can see from this Australian Government page about Nutrient Reference Values, there are quite a few different methods used, with the approach used and amounts recommended varying between countries. It really isn’t as cut and dried as you might think: there is no definitive “ideal nutrient intake” list. Researchers, organisations, governments and countries don’t necessarily all agree, and the lists we do have are a ‘best guess’ for the average person.

This is very helpful, and the information provided by government bodies is probably some of the best we have available to us, but it’s important to recognise the following:

*Recommendations change as ongoing research brings new information to light, and too much of a supplement can be just as concerning as a nutrient deficiency. What is advised as best practise now won’t necessarily be considered best practise in 5 years time. We have only to look at past and present changes in nutrition knowledge and government recommendations to see this in action. For example, nutrition textbooks in the past used to rate non-heme iron (iron from plants) as inferior to heme iron (iron from meat), because there is a poorer absorption rate from plant-based iron. What we now know is that using plants as our source of iron ensures the body (a highly intelligent system) has control over the absorption efficiency, adjusting intake to suit needs. Our body can’t do this with heme-iron: we have to absorb it whether we need it or not, and too much iron isn’t good for us. I’ll keep using iron as my example to illustrate what I’m talking about through the rest of this blog.

*”Optimum” doesn’t automatically equate with “more”. Just because something is bad for you when its absent (eg a nutrient deficiency) doesn’t automatically mean that having bucket-loads of it is going to be good for you. If you are deficient, supplementation can be a life-changer, yes; but provide more than is needed to correct the deficiency, and at best, you are wasting money and resources. You might even be doing yourself some harm.

We seem to have a strange obsession with getting MORE nutrition all the time, often forcing supplements into bodies that don’t needs them, in forms that are alien to the body, and in combinations or ratios that are unnatural and can contribute to imbalances. It isn’t easy to get rid of iron once it’s in our body, which is why its a smart idea not to overload it in the first place. Iron is a pro-oxidant, so too much can damage DNA and other molecules. High iron intakes are being associated with Alzheimer’s and Parkinson’s diseases, arthritis, type 2 diabetes, cardiovascular disease and cancer (esp colorectal).

So if I had an iron deficiency, an iron supplement could be highly beneficial to me. But if I didn’t, that supplement might be contributing to some pretty significant disease progression. And we are only just learning this about iron now! Yes, some estimates for recommended daily intake are too low, but some may be too high. I err on the side of caution by sourcing my nutrition from food rather than supplements (where possible) and letting the wisdom of my body sort out what is best for me. I try to provide my body with a broad range of nutrients from a diverse range of whole plant foods, while limiting my intake of empty calories and processed (nutrient-stripped) foods. I also try to avoid behaviours that chew up nutrients eg not sleeping properly, getting stressed etc.

*There is a big difference between a recommended daily intake (which is the average daily amount needed to keep the average person in good health) and a supplemental range, which is the amount needed to correct a nutrient deficiency or when using a supplement as a form of therapy for a specific illness. The supplemental range is much higher than the RDI, and it’s probably this range you are thinking of, rather than the more normal daily intake we need to avoid a deficiency.

It really isn’t a good idea to take supplements at these higher doses for ongoing periods of time, without professional guidance. And to be perfectly honest, I think most of us professionals are a wee bit over-confident about our knowledge of the body and nutrition, and some are tending to overdose people. Let me give you an insight into the complexities of nutrition for a moment: I’ve already told you about how iron absorption changes depending on whether the iron is coming from a plant or an animal… Absorption also changes in response to your age, sex, medical conditions, the way foods and/or supplements are combined, the way food is cooked etc.

If you are a woman who is pregnant, your needs are higher than those needed for a man, and your iron absorption rate will increase dramatically to compensate for this. The health of your stomach has a big influence over iron absorption and drugs that decrease stomach acid can seriously hinder iron absorption. Mind you, so can a strong cup of tea eaten with your meals; or that course of antibiotics you just took; or the pain-killers you’ve been using; or the calcium, zinc, and/or magnesium supplements you’ve been taking.

And it really isn’t all just about provision and absorption; equally significant are the things you do that increase or decrease your body’s demand for a nutrient. Yes, the iron needs to be present in our diet and absorption needs to be working well and managed by the natural intelligence of the body… but once it gets into the blood stream one person’s use and excretion of absorbed iron might be greater or lesser than another’s.

*The recommendations are averages, drawn from research into large groups of people. Good reference charts will provide nutrient recommendations for different sexes and stages of life, for example, but even then, individual needs are quite variable. Nutrition is actually very complex: my need for iron might be a lot less than another person’s need for iron, because I don’t have a highly processed diet and I don’t pop calcium tablets ‘just in case’. But if I have digestive problems or a caffeine addiction, my need for iron might be higher. The RDI for iron gives me a broad idea about the average amount needed in my diet, and this is a good starting point, but it doesn’t tell me anything about my own individual needs. Again, my philosophy is to stick with foods rather than supplements where possible, because:

  1. It’s pretty difficult to overdose on nutrients that come from real food.
  2. The nutrient array in whole plant foods is perfectly designed by nature in ideal ratios.
  3. When a nutrient comes from a whole food, it’s in a natural form that my body recognises and can take or leave, depending in it’s own intelligent self-assessment of its needs at that time. Nutrients work best when they are combined with other nutrients in specific ratios. This is called ‘synergism’. Some of the synergistic nutrients for iron include Vitamins B2 and 12, Vitamin C, lysine, molybdenum, folic acid, selenium, histadine and copper.
  4. I know that the list of needed nutrients for good health is much bigger than the current nutrients that are being focused on. For example, I’m keen on immuno-modulating polysaccharides, mucilages and bioflavonoids… and I can’t get these in a pill.

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