The Importance of Vitamin Intake for Human Nutrition, Fitness, and Health
By Friedrich Reuss, Egloffstein
Vitamins are organic substances that have a catalytic function in the body in the biochemical reactions of metabolism. They must be supplied from outside and are not building materials of the body (otherwise, for example, amino acids would also have to be counted among the vitamins).
The classic view assumes that an insufficient supply of a vitamin quickly leads to a reduction in the relevant biochemical reactions and ultimately to the collapse of the body.
A severe vitamin deficiency is not compatible with life in the long term.
Based on this concept, vitamin researchers long believed they could determine human vitamin requirements quickly and reliably through experiments that create an artificial vitamin deficiency. Initial uncertainties in the method arose from the fact that tolerance of a borderline vitamin supply was found to vary greatly among people. This is evidently dependent on genetic factors (including absorption), on the presence and availability of other nutrients, and on current metabolic activity.
Later it was recognized that most vitamins control a large number of biochemical reactions and that different amounts of vitamins are sufficient for their function. Thus, the experimentally determined human vitamin requirement depends on the metabolic function used as the benchmark.
In this situation, it is clear that the human vitamin requirement ultimately depends on the biochemical function that requires the highest intake of a vitamin. That sounds simple, but it has far-reaching consequences, because no one can assume that we already know all the functions of a vitamin. The opposite is probably more likely to be true, namely that for most vitamins we do not yet know all the functions they control.
A typical example is vitamin K, which used to be regarded only as a coagulation vitamin and for which a vitamin requirement of about 40–80 µg per day was then assumed. Today we know that vitamin K also plays a very important role in the synthesis and remodeling of collagen and bone substance. For this function, however, much higher vitamin intakes are obviously optimal—the discussion currently ranges between 250 and 1,000 µg (amounts that can certainly be achieved with green vegetables).
A similar example is vitamin C, for which very small amounts (20–40 mg) are apparently sufficient to maintain collagen synthesis in humans. For antioxidant cell protection, however, much higher intakes (roughly between 200 and 1,000 mg) are required, and here we are still in the phase of dose optimization.
Effects of a Vitamin Deficiency
Some vitamin effects take place, as it were, in secret, and the difference between a good and a poor vitamin supply only becomes visible after months, years, or even decades. These are periods that go far beyond the time frame of earlier vitamin studies. Precise new scientific findings can only be expected here after a long time. Especially with vitamins that have an antioxidant effect, studies to identify an optimal supply are difficult because damage caused by insufficient vitamin supply often only becomes visible after decades.
Although the biochemist or laboratory physician can estimate antioxidant cell protection using some laboratory values, the influence on long-term health can only be reliably assessed and quantified under real-time conditions.
The situation is similar with vitamin effects that are intended to ensure cancer protection or the maintenance of an efficient immune system in healthy individuals.
In this situation, the highly ethical health-policy question arises as to whether one should wait until, for example, cancer protection through antioxidant nutrients has been measured exactly, or whether vitamin recommendations should be raised as soon as the positive trend has been confirmed, without any harmful effect being known. We currently face this core question particularly with antioxidant vitamins.
We know that a substantially higher intake than the basic intake recommended to date reduces the risk of numerous diseases. Nevertheless, the authorities in some countries refuse to recognize higher vitamin intakes as nutrition. Apparently, many millions more people must die of lifestyle diseases before statistical data are good enough for the authorities and national nutrition societies to significantly raise vitamin consumption recommendations.
Of course, vitamin dosages should be set so that no harm can come to people even under unfavorable circumstances. Decades of experience with the use of dietary supplements in countries with “liberal food law” have shown that serious undesirable vitamin effects are extremely rare. To the extent that intoxications became known at all, they were based on gross misuse or on serious misdosing of critical vitamins by the manufacturer. Thus, it was soon realized that only vitamins A and D actually pose a certain risk, because here the safety factor between recommended intake and a possibly adverse dose is less than 10. More recent scientific findings, however, have largely given the all-clear here as well: vitamin A is no longer considered nearly as embryotoxic today, and vitamin D, according to current knowledge, is also harmless up to relatively high and generally unnecessarily high dosages. The strict limitation of dietary supplementation with vitamins A and D in Germany is therefore scientifically long outdated; nevertheless, there has been no change in thinking by the German authorities. Only the constraints imposed by EU law will initiate normalization here.
Official Recommendations – Optimal Supply?
In simplified terms, it can be said today that the B vitamins, vitamin C, and vitamin E are safe up to 100 times the official basic recommendation, and vitamins A and K up to 10 times, and vitamin D at least up to 5 times.
We can therefore use modern vitamin dosages without relevant risks. However, it is always wise to use vitamins in sensible combinations and not to consume a single vitamin in extreme doses. In this context, it is important to know that even the beneficial antioxidant vitamins can become pro-oxidative when supplied excessively—if they are taken individually. Combining the antioxidant vitamins with one another and with antioxidant secondary plant compounds eliminates the pro-oxidative risk with a high degree of certainty, so that food-law quantity limits for the nutrients mentioned are not justified.
A new way of approaching optimal vitamin intake is Stone Age nutrition research. Various research groups around the world have compiled findings on the diet of our ancestors. Despite all the differences due to climatic and regional variations, it can be said that our ancestors consumed up to 10 times as many vitamins (and other micronutrients) as the current official recommendations state. Further details on this can be found in my article on Stone Age nutrition.
The Evolution of Nutrition Over the Last 100 Years
Modern nutrition has become considerably poorer in vitamins, especially over the last 100 years: increased agricultural yields have resulted in lower vitamin densities, and industrial processing and storage have deprived food of a large proportion of its vitamins. A typical example is grain: during milling, the vitamin-rich germ is removed; at times, even the remaining vitamin B2 was bleached away; the flour was depleted of vitamins through long storage periods under the pretext of improved baking quality; and the last traces of vitamins were finally further reduced by cooking and baking. The last 100 years of the food industry have been a period of progressive food destruction and a consistent path toward the programmed early demise of the unsuspecting consumer. Only the idea of reform nutrition and, today, organic nutrition have led to a slow change in thinking. But anyone who, for example, has consumed inferior, vitamin-depleted food for 50 years has probably forfeited many possible years of healthy life as a result. This can hardly be reversed even with expensive, high-dose dietary supplements.
Our Options Today
According to current knowledge, humans are biologically quite capable of living 100–120 years in good health if they optimize their lifestyle, diet, and especially their vitamin intake. A philosopher would have to say “The art of life consists of growing old in good health and dying, if possible, without illness.” (A truly provocative idea for many economic circles that currently profit from the German “sickness system”!) With optimal nutrition or vitamin supply and a sensible lifestyle (avoiding stress and engaging in moderate physical activity), this is achievable for most people! We only have to want it consistently and also enforce the political prerequisites for it. European citizens have a legal right to healthy nutrition and sensible dietary supplementation and must demand this from politicians. The nutrition societies, driven by scientific inertia, industry interests, and self-interest, are obviously not to be relied upon in this regard! (See also the separate article on the correction of the DGE nutrient recommendations in 2000!)
About Our Guest Author Friedrich Reuss
Friedrich Reuss completed his chemistry studies with a diploma at the University of Münster in 1966. He then worked as a research associate at the Institute of Organic Chemistry and was active in Prof. Dyong’s department in the field of bioactive plant sugars. After working as a chemistry teacher, Friedrich Reuss spent almost 25 years as a research associate at a renowned pharmaceutical company. His focus was on researching artificial nutrition as well as investigating amino acids, vitamins, minerals, trace elements, carnitines, taurines, and glutathione.
Since 1993, he has been an officially appointed expert of the Nuremberg Chamber of Industry and Commerce, specializing in special foods such as dietary supplements and sports nutrition. Since 2013, he has also been an appointed expert for the IHK Suhl/Thuringia. Over the past 25 years, as part of his work, he has supervised the approval of at least 500 dietary supplements. His expert opinions have influenced not only many decisions of Germany’s highest court, but also those of the European Court of Justice.
He is the author of numerous scientific publications as well as a book on the nutritional-medical significance of glutathione for cells and immunity.
