Ever look at RDI’s (Recommended daily intakes) of nutrients, and then look at how much of something is in a nutrient supplement and wonder why one is so very low, and the other is so high?
It’s all due to the difference between RDI and therapeutic dose. But.. to confound things a little, there is the idea of 'optimal dose. And now there is an EAR, which is the Estimated Average Requirement.
Erica, our naturopath says that RDI’s are only established for nutrients the boffins consider essential. This, she says, makes for some rather glaring omissions, such as potassium. No RDI for it.
So it appears we are forced to conclude that an RDI is how much you need of anything in order to not get deficiency diseases. For vitamin C, (so you don’t get scurvy), the RDI is… well… this is where it starts to get confusing.
To maintain a suitable body pool in healthy 76-kg men and 62-kg women requires daily intakes (RDI) of 40 mg and 30 mg respectively.
EAR: 30 mg / day and RDI 45 mg/day.
This is for both men and women, from 19 – over 70 years of age.
In pregnancy the numbers are a bit higher. (from the Australian NHMRC).
Yes, you heard right! a young man of 19, most probably still growing, needs the same amount of vitamin C as a 40-year-old person.
Then you get the research into the optimal intake:
“Based on the combined evidence from human metabolic, pharmacokinetic, and observational studies and Phase II RCTs, we conclude that 200 mg per day is the optimum dietary intake of vitamin C for the majority of the adult population to maximize the vitamin's potential health benefits with the least risk of inadequacy or adverse health effects.”
Next up is the therapeutic dose, or supplemental range.
This is the theory of how much of a nutrient you need to treat a condition. It is based on research into how much of something you need to take to get any change in a health condition.
Take zinc for example.
The RDI is 15 mg, but to support the immune system when you have a cold you need about 90 mg a day. This doesn’t mean take 90 mg a day and you will never get a cold, it means that for the duration of the cold, that much zinc may help reduce the severity of symptoms and help in fighting the infection.
Taking too much zinc for too long will wipe out your copper stores. And before you start saying “fantastic copper is dangerous”, think again. Copper is essential for brain function, making white blood cells and making connective tissue, including collagen, oh, and keeping pigment in hair.
There is also the theory of how much of something you need to take in order to get any benefit at all. I think this idea is easiest explained with herbs. Consider how weak a cup of coffee would be if you only put in a pinch, instead of the usual teaspoon. Wouldn’t be worth drinking would it? (Yes I know, there are the ¼ strength decaf with hazelnut syrup drinkers out there, but I’m suspecting they aren’t after the caffeine, or the coffee for that matter.)
What I think it comes down to is that you need to take enough of something to have an effect, but not too much. My mind boggles when I see formulas, whether they are plant or nutrient based that have every ingredient you can think of in them, but only in tiny amounts.
The nutrient ones are down at RDI level, if that. If you aren’t getting enough of each nutrient to meet RDI’s then you seriously need to look at your diet.
It is the large doses taken in order to make a change to your health that supplements are for. I think most of these should be taken while you sort out your diet and lifestyle in order to get your nutrients from your food. If the minerals aren’t in the plants you are eating, then find a better supplier, or grow your own; in soil that has the nutrients (but that is another challenge). The whole eat seasonally and locally idea helps me with that.
My mind is way past bogging into downright chuckling though when I see plant based, and usually labelled some sort of green superfood, formula, with 75 or 100 ingredients. It’s marketed as having the benefit of all 75 ingredients. And you only need to take a teaspoon of it to get all those benefits.
Seriously, how much of anything are you going to get from the miniscule amount of any plant you can get 75 of in a teaspoon?
So, how much does Goldilocks need? Well, Goldilocks is a kid so usually much less than an adult, but let’s talk about Mrs and Mr Goldilocks, young Goldie’s parents. Below is a table of optimum nutrient values for many nutrients. The info is a bit old, but I think it is still more valuable in maintaining good health than an RDI.
Nutrient Optimal Intake
Vitamin A 10-30mg
B1 – thiamine 5-10mg
B2 – riboflavin 5-10mg
B3 – niacin 10-100mg
B6 – Pyridoxine 2-50mg
B12 – Cobalamin 11-100mg
B5 – pantothenic acid 10mg
Vitamin C 200mg
Vitamin D 20 to 25 mcg (800 to 1,000 IU)
Vitamin E 67-500mg
Vitamin K 60-300mcg
The above values are for maintaining optimal health, not for treating disease conditions, or correcting specific nutrient deficiencies. And it is from all sources, not supplements per se.
Therapeutic doses are much higher than optimal doses and they change for what condition you are treating. So, please, see a health professional before starting to take large doses of anything. Irrespective of what Dr Google says.
Personally, I don’t take any supplement every day. I take them as and when I need them. If I am having cravings then I may take the nutrients that are particularly high in those foods till the cravings are gone. If I have a few drinks, then I will take a liver support tablet and eat really well.
The take home message, dear seekers of health, is everything in moderation, including moderation.