Where do the daily consumption recommendations come from? When does it make sense to take more than the 100% NRV amount? What are the maximum permitted quantities? When should I take which dietary supplement? What do I mean?E. with vitamins and how can this be expressed in mg or mcg can be converted?
We will try to provide answers to all of these questions in the following blog post.
Publisher and validity of reference values
There are a number of committees that make dosage recommendations for each micronutrient. The fact that the recommendations vary by a factor of 4 to 100 (!) depending on the committee shows very clearly that there is obviously no one, fixed size as a guideline.
The following are the committees relevant to the DACH region and internationally that deal with the determination of reference values:
• German Society for Nutrition (DGE)
(Recommendations for nutrient intake; first published in 1956)
• Austrian Society for Nutrition (ÖGE)
• Swiss Society for Nutritional Research (SGE)
• Swiss Association for Nutrition (SVE)
• Food and Nutrition Board (USA)
(Recommended Dietary Allowances RDA; first in 1943)
• Food and Agriculture Organization (FAO) of the WHO
(Handbook on Human Nutritional Requirements)
• European Food Savety Authority (EFSA); since 2003
--> Recommendations vary by a factor of 4-100 depending on the committee!
Examples of reference values for middle-aged women:
(Source: https://www.dge.de/wissenschaft/referenzwerte/tool/)
When setting reference values, these committees set certain premises. The reference values (example for the DGE) only apply to:
-
Average requirement (according to Estimation, surveys, studies)
- from healthy people
- with an average lifestyle
- without any special burdens
- Avoidance of shortages as a target variable
-
Not valid for
- People with stress
- Sick people
-
Without taking variables into account
- Individual needs (no Gaussian normal distribution)
- Needs according to age, gender, physical performance
- Increased demand (e.g.b Everyday stress, illness)
- Decreased intake
The DGE explains the “average lifestyle” with regard to nutrition as follows:
- “Fruit and vegetables 5 times a day, including 3 portions of 375 g of vegetables and 2 portions of 250-300 g of fruit – preferably fresh!”
-
“For people at risk, a targeted intake of nutritional supplements can be useful, e.g.b for smokers, pregnant women, reduction diets, seniors, gastrointestinal diseases.”
(Source: Annette Braun, press spokeswoman for the DGE in ÄZ 19.71999)
It is already clear that the reference values determined in this way can hardly have general validity. For example, who is free from burdens such as stress, environmental toxins, everyday drugs etc? Who is completely “healthy”? And here you don't even have to think about serious illnesses - just an absorption disorder in the intestine ensures that only a fraction of the nutrients supplied actually reach the cells. Also often undetected “silent inflammation” (chronic inflammation), e.g. due to autoimmune diseases, for example to an increased need for micronutrients.
The undisputed increased need among old people, athletes, etc. is also ignored. In addition, it is assumed that a normal/healthy, balanced diet is present, which is often not possible for most people in everyday life.
It must also be emphasized that the goal when setting the reference values is always just the prevention of deficiency symptoms. DH the purely preventive idea. It is therefore clear that the therapeutic use of micronutrients or Replenishing nutrient depots that are too low must always be accompanied by a dosage above the specified reference values.
// All official recommendations for daily nutrient intake refer to healthy normal people without risks and with full micronutrient stores! //
BfR – maximum quantity recommendations (2018)
In addition to the recommended reference values, which are determined individually by each committee based on the premises presented above and which follow the preventive idea of maintaining health, there are also committees that are concerned with setting maximum amounts for micronutrients. In Germany this is the Federal Institute for Risk Assessment (BfR), which derives the maximum values based on 3 parameters:
- Tolerable maximum daily intake levels [UL]
- Intake quantities through the usual diet
- Intake reference values (recommended amounts for daily intake)
The safe intake level for dietary supplements (incl. fortified foods) is derived as follows:
- Tolerable maximum daily intake (UL) less Nutrient intake from the usual diet (reference value) = safe intake level
- D.H: If the reference value is not reached through diet, the NEM dose can be higher, if necessary. up to the highest daily intake (UL)!
BfR maximum quantity recommendations
(as of: 16.32021)
|
Dietary supplements |
Food & Drinks |
Vitamin A |
0.2 mg |
1 mg |
Vitamin B3 |
160 mg |
47 mg |
Vitamin B6 |
3.5 mg |
1.08 mg |
Vitamin B12 |
25 mcg |
7.6 mcg |
Folic acid |
200 (400) mcg |
- |
Vitamin C |
250 mg |
76 mg |
Vitamin D |
20 mcg (800 IU) |
- |
Vitamin E |
30 mg |
9 mg |
Vitamin K1 + K2 |
80 + 25 mcg |
- |
Vitamin B1, B2, pantothenic acid, biotin |
No limit |
No limit |
Chrome |
60 mcg |
19 mcg |
Fluoride |
- |
- |
Iron |
6 mg |
- |
Iodine |
100 (150) mcg |
Salt 2500 mcg/100 g |
Copper |
1 mg |
- |
Manganese |
0.5 mg |
- |
Molybdenum |
80 mcg |
24 mcg |
Selenium |
45 mcg |
- |
Zinc |
6.5 mg |
- |
Calcium |
500 mg |
120 mg/100 ml |
Chloride |
- |
- |
Potassium |
500 mg |
- |
Magnesium |
250 mg |
39 mg |
Sodium |
- |
- |
Phosphorus |
- |
- |
Overdose risks
-
Vitamins à Dosage usually rather high and broad
- Water-soluble vitamins (B, C): d.R no risk of overdose, as increased amounts are simply excreted via the kidneys/urine
-
Fat-soluble vitamins (A, D, E, K): Risk of hypervitaminosis
- A (25000 – 83000 IU)
- β-carotene (smokers < 15 mg)
(with a very unbalanced diet & high intake via preparations) - D (only with high mirrors from approx. 150 ng/ml and higher)
- Vit. B3 (only with high intake of 1-2 g/d)
-
Minerals & trace elements à Dosage rather cautiously (low therapeutic range)
- In high quantities: All toxic
- Moderate risk: calcium, magnesium, iodine (factor UR/RAD = 5-100)
- Increased risk: iron, phosphorus, zinc, selenium (factor UL/RDA < 5)
- Basically toxic: e.g.b Mercury, cadmium
As with the determination of the reference values, there are also significant deviations from country to country when it comes to the maximum quantities - and it turns out that Germany is here.dR is far below the values of neighboring European countries (Source: https://www.verbraucherzentrale.nrw/sites/default/files/2021-04/Hoechstmengen_Europa_April%202021.pdf):
The following graphic shows the recommended intake amount and the maximum amount (UL). The principle applies that a dosage with the recommended intake (these are the “100% NRV” on the product labels of dietary supplements) is intended to maintain health, i.e.H Prevention, in healthy people without any particular stress and with filled micronutrient stores.
Above the recommended “100% NRV” amount, the area of prevention begins if the nutrient stores are not completely filled and/or there are special stresses. If the dosage is further increased up to the defined maximum amount (UL), one then enters the therapeutic area of application - i.e.H the use of micronutrients for (accompanying) therapy of an already manifest disease.
D.H In practice, the dosage must be adjusted individually according to...
- Area of application (primary, secondary prevention, therapy, aftercare)
- Indication (e.g.b Severity of the disease)
- Monotherapy or combination administration (combination reduces single dose)
- Substance group (e.g.b For water-soluble vitamins, the dosage range is rather large and for fat-soluble vitamins, the dosage range is rather narrow)
- Age, gender, situation (e.g.b pregnancy)
- Recommendations (studies, literature, DGE etc)
- Laboratory values (levels of substances and markers)
- Low normal load (e.g.b Prevention): Low normal substance levels usually sufficient
- High stress, high risks, advanced or severe disease: usually higher substance levels required
- Low initial levels of a substance: usually high (possibly parenteral) dosage
"Rule of thumb" when dosing orthomolecular substances from practice
-
Prevention of deficiency symptoms
- usually 1x recommendations from the RDA / DGE
-
Preventive focus
- usually up to 3 times the recommendations of the RDA / DGE
-
Example intake recommendations for vitamin C “to prevent illness”:
- For adults: Daily intake 100 mg according to. DGE
- For primates in captivity: Daily intake 55 mg vitamin C / kg body weight (!) à h. for a person weighing 70 kg this would be 3850 mg per day (!)
-
Therapeutic use & targeted supplements
- High doses of individual substances
Consideration of bioavailability variables
- Ultimately, it is not the dose administered that decides, but what actually reaches the body!
- Basically different bioavailability of individual substances
- Different bioavailability and compound form of individual preparations
- Time of supply (e.g.b Interactions, fatty foods)
- Individually different digestion and absorption capacity
- Functionality of metabolism and intestines (digestion, absorption)
-
Consequence:
- Dosage according to blood level (no fixed dosages)
-
Consequence for prevention and for preventive studies (!)
- With high blood levels, no positive effects with increased intake
- with low blood levels, low bioavailability and
functional disorders (e.g.b Intestine) higher dosages required
General recommendations for when to take important micronutrients
-
Vitamins
- Spread water-soluble vitamins into several doses, especially at higher doses (give before meals)
- Give fat-soluble vitamins as 1 dose (give with meals) / Attention: Benfotiamine (vitamin B1) is fat-soluble!
- Add combinations of water- and fat-soluble vitamins to meals
-
Minerals and trace elements
- Especially at higher dosages, there is a difference between zinc, iron, copper, calcium,
manganese, magnesium and fluorine preparations as well as between these substances and
chelating agents (e.g.b α-lipoic acid) a distance of approx. 2 hours and maybe Distribution over several doses recommended
- Especially at higher dosages, there is a difference between zinc, iron, copper, calcium,
Recommendation |
Substance examples |
Before meal |
B vitamins, vitamin C |
During or immediately after a meal (e.g.b because of stomach acid) |
Calcium (possibly evening), magnesium, |
During or immediately after a meal (v.a because of fat solubility) |
Vitamin A, D, E, K, carotenoids, |
Fast or independent of meal (due to possible Absorption restricted by |
Potassium, chromium, |
Between meals |
Proteases |
Biological activities of vitamin forms: conversion of IU / mg or mcg
Vitamin |
Basic value |
Corresponding biological activity |
Vitamin A |
1 mg vitamin A |
1 mg retinol (definition) = “retinol equivalent” |
Vitamin D |
1 mg cholecalciferol / D3 |
40 million IU Vitamin D |
Vitamin E |
1 mg vitamin E |
1 mg RRR-α-tocopherol (definition) = d-α-Toc. |
Vitamin |
Basic value |
Corresponding biological activity contained in |
Vitamin B1 |
1 mg B1 (thiamine) |
1.32 mg thiamine hydrochloride DAB |
Vitamin B2 |
1 mg B2 (riboflavin) |
1.42 mg riboflavin 5'-phosphate Na dihydrate DAB |
Vitamin B6 |
1 mg B6 (pyridoxine) |
1.22 mg pyridoxine hydrochloride DAB |
Pantothenic acid |
1 mg pantothenic acid |
1.11 mg calcium D-pantothenate DAB |
Vitamin C |
1 mg vitamin C |
1 mg ascorbic acid DAB |