Nutri Courses

Advisory

Dietary supplements

Dietary supplements are products designed to complement the regular diet with concentrated amounts of nutrients or other substances with nutritional or physiological effects. They are produced in various forms - such as tablets, capsules, liquids, powders, etc. They are manufactured to provide nutrients that may not be sufficiently represented in an individual's regular diet.

Hello, Mr. Jelínek,

What amount of garlic per day is suitable for a person with low blood pressure? And what would you recommend to increase blood pressure?

Thank you.

In this case, it depends on the quality (= content of active nutrients) and form (raw x cooked x dietary supplement...) in which you consume garlic. Heat treatment destroys the vast majority of substances that lower blood pressure, while for dietary supplements, the method of technological processing of the product is crucial, i.e., the amount of active ingredients the manufacturer guarantees in the product. In practice, it is common that some supplements have virtually no effect, while others significantly influence blood pressure.

The best way to raise blood pressure is through stress or physical activity (the second option is considerably more beneficial for health :-).

Hello,

Do I understand correctly that quercetin cannot be consumed in diet in amounts that match supplementation levels? Let's say in a regular diet it's 50 mg, in specialized diets more, but not 500 mg? And in this case, does supplementation always make sense?

Under normal conditions, it is essentially impossible to consume such a high amount of quercetin on a daily basis, which is where supplementation has its clear significance. This is a typical example of the role dietary supplements can play in the quality of nutrition.

Hello,
Could you please specify which echinacea meets both criteria, as the preparations available on the market do not specify the content of both substances?
Thank you.

When selecting a preparation containing echinacea, always consider its quality by checking the label for information about the content of these two substances (cichoric acid and alkamides). If they are not listed, it is clear that the product does not contain a standardized extract, making it pointless to purchase the supplement at all. Echinacea is among the best-selling herbs worldwide; unfortunately, this popularity leads to fraudulent manipulations of quality by dietary supplement manufacturers. Analyses even show that it is common for a manufacturer to guarantee the content of a standardized extract, but it is not actually present. Such practices are frequent in the dietary supplement industry, and consumers essentially have two options to obtain a quality product:
1. The first is to choose based on certifications, preferably from independent companies (if the manufacturer/seller has them, they will always showcase them).
2. The second is ongoing testing of selected products.

Hello,
I would like to ask what doses of individual vitamins you recommend for a professional athlete (example: team sport, female, 25 years old, and training 7-9 times a week and 1-2 matches). Is it even possible to obtain all the vitamins from the diet in this case, or is it necessary to take dietary supplements?
Thank you, and have a nice day.

In this case, it is not so much about what I would recommend, but what the athlete actually needs. Generally (for the general population), it is presented that with increasing physical and mental stress, the need for micronutrients also increases. However, it is necessary to avoid any generalization because each athlete has different requirements, which depend not only on their metabolic profile but also on the extent of the stress. Moreover, there are differences between water-soluble and fat-soluble vitamins – the body does not store hydrophilic substances to the extent it does lipophilic components, which means they can be safely consumed in higher concentrations (in relation to their reference value). Calculating with reference values and their multiples is tricky because, for each substance, a safe limit is additionally defined, and at the same time, a distinction is made between the recommended and therapeutic dose. Ideally, it is always best to provide the amount of each nutrient that meets the individual's real requirements, which encounters the problem of choosing an analysis capable of determining the necessary quantity.

Certainly, expect that in a regime of multi-phase training, the athlete will not be able to supply all the vitamins in the necessary amounts solely from their diet, as their actual needs are usually within lower multiples of their RI. Therefore, supportive supplementation is always advisable, which further involves determining whether a multivitamin or the intake of individual substances through separate products is more suitable, allowing for better dosage manipulation.

Good day,

I would like to ask for your opinion on dietary supplements: vitamins and minerals. I feel that I am unable to monitor their daily intake above 100% through diet alone. Do you think it is a good idea to supplement some basic vitamins and minerals? For example, Vitamin C, B12, iodine (in the form of aronia), Omega-3, and magnesium?

Thank you :)

If your diet displays the fundamental characteristics of diversity, you prefer natural, meaning unprocessed foods, and simultaneously do not experiment with reduction diets with a significant energy deficit, you should not have a problem ensuring the basic intake of micronutrients. Generally, with increasing stress and physical load, the need for a higher intake of these substances also increases; in such situations, supportive supplementation makes sense.

Hello,
what dietary supplements would you recommend to a female vegetarian to reduce the prolactin levels in her blood? High levels have been identified in her laboratory tests. She has a very irregular and prolonged menstrual cycle, which she would like to regulate. So far, I have recommended chaste tree, maca, and ginkgo biloba. Is this the right choice? Is it advantageous to combine them, or should they be taken separately? And does it make sense to try to influence the condition by increasing soy in the diet, for example?
Thank you very much for your response.

Hormonal regulation disorders are difficult to address through dietary adjustments and supplementation. There are situations where they can be significantly helpful, but without determining the root cause of the problem, the likelihood of success is greatly reduced. Increased production of prolactin can also be caused by stress or fasting. It often happens with vegetarians who do not monitor the nutritional values of their diet that they find themselves in a significant energy deficit, which could be related.

However, consider this a theoretical speculation because increased prolactin levels are also influenced by contraceptives, psychopharmaceuticals, antihypertensives, and occur with pituitary dysfunction or certain tumor diseases.

Increased consumption of soy boosts the intake of phytoestrogens - if the condition were due to increased estrogen production, a higher intake of phytoestrogens could act anti-estrogenically. On the other hand, it is generally true that vegetarians have a relatively sufficient intake of phytoestrogens compared to the omnivorous population. Supplementation with vitex makes sense; you won't harm with the other mentioned supplements.

Hello,
I wanted to ask whether homeopathic remedies can be classified as dietary supplements. Or are they rather considered as medicines even though doctors may not like to hear that. Furthermore, there is much discussion nowadays about the negative impact of dietary supplements on the human body. How can one tell which supplement is truly effective?
Thank you

Homeopathy is essentially a well-defined class. From the perspective of its effects, it can be perceived as a medicine, but legislation does not treat it as such. Each country in the world views it differently; unfortunately, in the Czech Republic, it stands somewhat "on the sidelines." Everything is a matter of approach and perspective, as it depends on whether we approach its effects from a position of faith or, conversely, knowledge (orthodox science views it dismissively and is convinced that it is merely a placebo effect).

You will only recognize an effective supplement by trying it out. Serious manufacturers strive to present as much information as possible to convince the customer that their product is truly worthwhile. In practice, it makes sense to focus on these claims because they are often truthful. Moreover, it is often the only way to obtain information about the quality of the materials from which they are made. However, in terms of effects (specific influence on metabolism), they will never replace personal experience.

Hello,
I would like to inquire about the use of dietary supplements containing iodine. If potassium iodide or sodium iodate is listed in the ingredients, does that mean they are of synthetic origin and therefore not the best choice? What source of iodine would be most suitable in dietary supplements?
Thank you.

These minerals are not synthetic in origin; they are commonly used inorganic salts. It is generally claimed that they have lower bioavailability than organic salts, but the difference cannot be quantified, as numerous factors play a role in the process, with their scope and impact varying according to the individuality of the person. The only advantage of these supplements is that the amount of iodine they contain is declared, so the user knows how much of the substance (in relation to its reference value) they are consuming. If you want to focus on the intake of organic forms of iodine, it is beneficial to use chokeberry or seaweed in cooking. In the case of seaweed, the concentration of iodine is extremely high, so it is wise to consume only small amounts. Concerns about overdosing on iodine in this form are unnecessary for a healthy individual, as the body eliminates excess water-soluble substances, including iodine, through homeostatic systems.

Hello,
I would like to ask which form of magnesium supplement you consider the most suitable for an adult. Do you perceive any significant difference in the effect of using tablets or, for example, soluble sachets in the mouth, and is it important to take specific forms with meals or not?
Thank you in advance for your response, and have a nice day.

This is a question that requires a more complex debate, as the effectiveness of supportive supplementation is determined by several factors, and it is difficult to decide which one holds more weight. Fundamentally, it concerns the form in which magnesium is present in the supplement. The market offers organic forms such as malate, citrate, bisglycinate, lactate, threonate, laurate, etc., and inorganic ones like magnesium oxide, magnesium carbonate, or magnesium sulfate. It is generally accepted that organic forms are better absorbed, thus arguments are made in their favor.

Another criterion for choice may be the content of elemental magnesium in a single dose. Its amount is on average significantly higher in inorganic forms, which, however, boast (as commonly presented) lower absorbability (with a difference of up to an order of magnitude). This becomes debatable in situations where a supplement manufacturer adds selected plant materials (extracts, concentrates) to magnesium in its inorganic form (which is significantly cheaper), where the presence of phytochemicals (an organic source) has the potential to increase magnesium's bioavailability in the body. And precisely at this point, the challenge arises as to which direction to take—whether to follow the pharmacologically proven path with measurable results, or to respect the holistic order of nature and not address a one-sided perspective.

Personally, I am more inclined toward the synergy of natural principles, but each individual must answer this for themselves.

Hello,
In relation to celiac disease, I would like to ask about the absorption of nutrients in the small intestine from supplements. I believe that if nutrients from food are not absorbed, they will not be absorbed from supplements either, and we are unnecessarily burdening the body with them. Is it therefore an option to provide nutrients intravenously?
Thank you for your response and have a great day.

Nutrients are always absorbed in the small intestine affected by celiac disease, but only to a limited extent depending on the degree and extent of mucosal damage, which is an individual matter. This creates situations where impaired nutrient absorption can lead to nutritional deficiencies, most commonly occurring in the context of the long-term presence of such a health condition. In such situations, supplementation makes sense because substances from supplements are always absorbed more efficiently (i.e., in larger quantities) than from food. As long as you do not overdose on supplements, there is no need to worry about any unwanted strain on the body.

Hello,

I would like to ask, dietary supplements should not be washed down with coffee, which is obvious. Most people take supplements with water, but, for example, have coffee with breakfast. Does this affect the bioavailability of the supplements? Should there be a time interval?

Thank you.

The time gap is more advantageous, especially for supplements containing water-soluble substances, which the body tends to excrete at an increased rate after consuming diuretics, such as coffee. However, the specific time gap is relative, and there is no general metric for it – in general, consider tens of minutes as a "safe" interval.

Hello,

I would like to ask whether the use of dietary supplements that directly support the function of the immune system (such as beta-glucans, colostrum, or others) can reduce the effectiveness of vaccination if they are used long-term. Or do they not have such an impact?

Thank you.

These dietary supplements do not pose any problem with regard to vaccination. In general, supplements support the activity of the non-specific part of the immune system, whereas vaccination is aimed at stimulating specific antibody immunity. You can use them without worry.

Hello,

I would like to ask for your opinion on the additive in dietary supplements - magnesium stearate. Some sources say that it is a natural substance for the body that we commonly ingest in food, while I have also read that it can form a film and hinder the absorption of certain nutrients. Is it even physically possible for a substance consumed in small amounts in a supplement to cause such an effect?

Thank you.

Magnesium stearate is most commonly used as an anti-caking agent and filler in the production of dietary supplements. It is considered a health-safe substance. Since it is insoluble in water, there are occasional opinions that in the digestive tract, at higher doses, it may complicate the absorption of certain nutrients, but this has not been confirmed.

Questions answered by

Mgr. Martin Jelinek
Lecturer and author of the educational system

Mgr. Martin Jelínek has been systematically involved in nutrition education since 1999. He is the founder of ATAC, the educational company behind NutriCourses, and the author of an educational system focused on nutrition, healthy lifestyle, and the practical application of nutrition knowledge.

He graduated from the Faculty of Science at Masaryk University in Brno. Throughout his professional career, he has combined nutrition, education, and the practical application of acquired knowledge. His educational system also includes the ZOF (Zone of Optimal Functioning) learning application, where students turn theory into practical work with meal plans.

In 2007, he launched the first intake of a six-month course focused on the education of nutrition advisors. Over time, this course became the foundation for the further development of the educational system and a range of specialised courses.