Dietary Supplements: A Contemporary Perspective

From Vitamins to Personalized Nutrition

Dietary supplements have long ceased to be a niche product for supporters of a healthy lifestyle. Today, they are part of the everyday practice of millions of people, and in a number of countries more than half of the adult population regularly takes one supplement or another. At the same time, skepticism remains high: many physicians and patients still believe that dietary supplements either lack a sufficient evidence base or are practically unregulated by the state.

Two major publications released in 2024–2025 make it possible to look at this issue from a new perspective. The authors analyze not only the current state of the science on dietary supplements, but also their legal regulation, the quality of research, and the prospects for the development of personalized nutrition. The main conclusion of these papers is that perceptions of dietary supplements formed twenty to thirty years ago no longer reflect today’s scientific reality.

The Science of Dietary Supplements Has Come a Long Way

Historically, research on vitamins and micronutrients focused mainly on the prevention of deficiency states. The primary task was to prevent scurvy, rickets, pellagra (a disease caused by niacin deficiency — vitamin B3), iron-deficiency anemia, and other conditions associated with a lack of specific nutrients.

Modern nutritional science has substantially expanded the range of questions under investigation. Today, researchers are interested not only in correcting deficiency, but also in the effects of bioactive food components on metabolism, chronic inflammation, immunity, cognitive function, aging, and the risk of chronic disease.

According to the authors of the review, the shift from the concept of “deficiency prevention” to the concept of “health support” has become a key development of recent decades in the study of dietary supplements.

Why Do Research Findings Often Contradict One Another?

One reason for the ambiguous attitude toward dietary supplements remains the inconsistency of clinical studies. However, the authors emphasize that this does not always indicate a conflict of opinions. Rather, it reflects the individual response of the body to dietary supplements.

Dietary supplements act on an extremely complex biological system. The final outcome is influenced simultaneously by:

• the person’s baseline nutritional status;
• dietary patterns;
• age;
• genetic characteristics;
• gut microbiota (the community of microorganisms that inhabit a particular environment — the intestine, skin, oral cavity, and so on);
• lifestyle;
• comorbid conditions.

Therefore, two different people may respond very differently to the same supplement. While classical medicine has long sought universal recommendations, modern science is gradually moving toward a personalized approach.

This is why increasing attention is now being paid not to averaged study results, but to identifying groups of patients who actually obtain clinical benefit.

The Era of Personalized Nutrition

The authors identify the development of precision nutrition — personalized nutritional science — as one of the most promising areas.

Modern technologies make it possible to take into account not only a patient’s diet, but also genetic analysis data, metabolic characteristics, the composition of the gut microbiota, metabolic indicators, and other biomarkers.

In essence, this represents a transition from the principle of “one recommendation for everyone” to the individual selection of nutritional support.

There are also high expectations regarding the use of artificial intelligence and machine-learning methods. By analyzing large datasets, these technologies can identify patterns that cannot be detected using traditional statistical methods.

The authors believe that the combination of digital medicine and artificial intelligence will become the foundation for the next stage in the development of dietary supplement science.

The Microbiome as a New Object of Research

Another area that is rapidly changing perceptions of dietary supplements is the study of the gut microbiota.

It is now known that many food components affect the body not directly, but through changes in the composition and functions of gut microorganisms. Dietary fibers, prebiotics, probiotics, postbiotics, and various plant polyphenols are of particular interest.

At the same time, researchers caution against premature conclusions. Despite substantial interest in the microbiome, there is still no single definition of “healthy microbiota” (a narrower concept than the microbiome).

Are Dietary Supplements Regulated?

One of the most common myths remains the claim that the dietary supplement market is practically not controlled by the state.

The authors of the second review analyze U.S. legislation in detail and conclude that this perception is an oversimplification.

Dietary supplements are indeed regulated differently from medicinal products. However, this does not mean that there is no oversight.

Manufacturers are required to comply with requirements for manufacturing quality, product labeling, ingredient safety, reporting of serious adverse events, and the accuracy of information on packaging. Issues of safety and quality fall within the competence of the U.S. Food and Drug Administration (FDA).

At the same time, the authors acknowledge certain problems: a substantial part of oversight takes place after a product has already entered the market, which requires an effective safety monitoring system and a rapid response mechanism.

Are Studies Funded by Manufacturers Always Unreliable?

Another common myth is that any study funded by a dietary supplement manufacturer is biased a priori. The authors propose a more balanced approach.

The key factors are study design, randomization, adequate sample size, prior registration of the clinical trial, independent statistical analysis, and reproducibility of results.

In modern science, transparency of the research process is becoming one of the main criteria for the quality of evidence. Registration of studies before patient recruitment begins significantly reduces the risk of selective publication of positive results.

Can a Complete Diet Fully Replace Supplements?

In theory, a balanced diet can provide the body with most of the necessary nutrients. In real clinical practice, however, this is not always the case.

Even people with a varied diet often have insufficient intake of certain vitamins and micronutrients. The risk of deficiencies increases with restrictive diets, vegetarianism and veganism, reduced caloric intake, intense physical activity, and older age.

Interestingly, even dietary patterns considered exemplary (the Mediterranean and Japanese diets) do not always provide optimal intake of all nutrients.

This does not mean that supplements should be taken on a mass scale. Rather, the point is the rational use of dietary supplements to correct confirmed or probable deficiencies, not their uncontrolled use.

From Universal Recommendations to Evidence-Based Personalization

Modern nutritional science is gradually moving away from universal approaches. Whereas the key question used to be “does this supplement work?”, today it is being transformed into: “for which patients is it effective?”

Answering this question requires complex studies that take into account genetics, metabolic profile, microbiota, age, sex, lifestyle, and chronic diseases.

In the future, wearable digital devices, artificial intelligence, and large clinical databases will be used increasingly widely. This will make it possible to move toward truly personalized prevention.

At the same time, the authors emphasize that technological development does not replace the need for high-quality randomized clinical trials.

A Personalized Approach in Health Preservation Strategy

Modern science on dietary supplements is undergoing a profound transformation. New studies show that many traditional assumptions need to be reconsidered. Supplements should be viewed neither as a universal preventive tool nor as products without a scientific basis.

Their effectiveness is determined by a combination of factors: nutritional status, genetics, microbiota, lifestyle, and product quality. Adherence to the principles of evidence-based medicine, transparency of funding, and quality control remain essential.

A rational approach involves critical evaluation of the evidence, individualized selection of nutritional support, and the use only of products whose efficacy and safety have been confirmed.

As personalized medicine continues to develop, the role of dietary supplements is likely to grow. However, they should remain part of a comprehensive strategy for preserving health, not a substitute for it.

References

1. Gahche JJ, Kerstetter JE, Bailey RL, Jacquz EF, Dwyer JT. The evolution of dietary supplement science: from essential nutrients to personalized nutrition. Journal of Nutrition. 2024.

2. Antonio J, Antonio B, Aragon A, Bustillo E, Candow D, Collins R, et al. Common questions and misconceptions about dietary supplements and the industry – What does science and the law really say? Journal of the International Society of Sports Nutrition. 2025;22:2534128.