Reviewed by:
Dr. Patricia Núñez de Aysa — Medical expert in Longevity, specialist in Rehabilitation and Traumatology without surgery.
Dr. Joel Cuesta Gascón — Medical expert in sports medicine, rehabilitation, and nutrition.
Last updated: May 2026.
In 30 seconds
- The short answer is no: not everyone needs supplements. But the nuance is relevant, as they are becoming increasingly useful for more people.
- In Spain, 75% of the population has consumed a supplement in the last year, according to recent studies.
- The reason is not a trend: the nutritional quality of food has significantly declined in recent decades (FAO, 2024).
- The most common deficiencies are vitamin D, B12, omega-3, magnesium, iron, and protein. Each has specific risk profiles.
- A good supplement does not replace a good diet, but it can accompany it when the diet falls short.
The correct question is not "are they necessary?", but "in what cases?"
When someone asks if supplements are necessary for everyone, the quick answer is no. But, like almost everything in health, there are many nuances. The more useful question would be: in what situations does supplementation make sense and in which does it not?
It depends on several factors: whether your diet covers essential nutrients, whether you have any underlying pathology, what stage of life you are in, your level of physical activity, your sun exposure, your microbiota... The answer changes for each person.
What the data says: how supplements are consumed in Spain
According to recent studies and data from the FIAB (Spanish Federation of Food and Beverage Industries), supplement consumption in Spain has grown steadily in recent years. Some relevant data:
- 75% of the Spanish population has consumed a supplement in the last year.
- Use is more frequent in women than in men.
- The most consumed products are: multivitamins, magnesium, zinc, calcium, omega-3, and probiotics.
- In the athletic population, consumption is lower in volume but more regular and forms a structural part of their diet.
These numbers reflect something deeper than a trend. They reflect that it is becoming increasingly difficult to cover all essential nutrients with diet alone.
Why today's diet is not like before
The nutritional quality of food has significantly decreased in recent decades. This is not a perception: it is stated by the United Nations Food and Agriculture Organization (FAO) in its 2024 report and multiple subsequent independent studies.
Several factors explain this change:
1. Lifestyle and poorer nutrition
Work stress, lack of time, and lack of sleep favor more palatable, quick, and ultra-processed meals. We eat worse not out of ignorance, but because modern life pushes us in that direction.
2. Rising cost of nutrient-rich foods
Oily fish, nuts, quality legumes, or organic vegetables are more expensive. Food inflation in recent years has shifted consumption towards nutritionally inferior alternatives.
3. Lower nutritional density in foods
A study published in the International Journal of Food Sciences and Nutrition (2022) compares the mineral content of fruits and vegetables in the UK between 1940 and 2019. The conclusion: current foods contain less magnesium, iron, and zinc than their equivalents from 80 years ago. Intensive farming, soil depletion, and commercial varieties selected for yield (not nutrition) explain much of the phenomenon.
4. Changes in environmental exposure
Indoor jobs, less sun exposure, less contact with soil, voluntary restrictive diets or due to intolerance... All of this creates a scenario where deficiencies are more frequent than two generations ago.
When it does make sense to take supplements
It's not about supplementing by default, but about identifying specific situations where supplementation has a solid basis. These are the most common cases:
| Situation | Supplement to consider |
|---|---|
| Strict vegan or vegetarian diet | Vitamin B12 (essential) |
| Low consumption of oily fish or nuts | Omega-3 (EPA + DHA) |
| Low sun exposure, office work, high latitudes | Vitamin D3 (with K2 and magnesium) |
| Insufficient protein intake | Protein (whey or vegetable) |
| Sustained stress, poor rest, cramps | Magnesium |
| Women of childbearing age with heavy menstruation | Iron (with prior analysis) |
| Perimenopause and menopause | Vitamin D3, magnesium, phytoestrogens |
| Pregnancy and lactation | Folic acid, iodine, omega-3 |
| Older adults | Vitamin D, B12, magnesium, protein |
| Athletes with demanding workloads | Magnesium, omega-3, protein, vitamin D |
When it makes NO sense to supplement
It's just as important to know when supplementation is unnecessary:
- When your diet covers essential nutrients and you have no risk factors.
- When seeking a "miracle" to reverse habits that are not being addressed (poor diet, sedentary lifestyle, poor rest).
- When accumulating 10 or 12 bottles "just in case" without knowing what each one does.
- When there are underlying pathologies that require medical prescription and are replaced by supplements without supervision.
- When choosing products without traceability, without declared quality, and at suspiciously low prices.
A supplement is a tool, not a solution. And like any tool, if misused, it gets in the way.
Is supplementation a long-term solution?
It's a legitimate question. The honest answer: it shouldn't be under ideal conditions. Ideally, there would be a varied diet, nutrient-dense foods, sufficient sun exposure, and a lifestyle that doesn't deplete our reserves. But ideal conditions are not real for most people, and it doesn't seem like they will be in the short term.
Given this reality, supplements can play a useful role: covering what the diet doesn't provide, supporting demanding life stages, and helping to maintain daily well-being. Provided they are chosen well.
What to look for in a good supplement
- Scientific evidence behind each ingredient, not just marketing.
- Effective dosages, not symbolic doses to fill labels.
- Absorbable chemical form (e.g., bisglycinate for magnesium, not oxide).
- No unnecessary excipients (titanium dioxide, excessive stearates, sweeteners).
- Manufactured to quality standards (ISO 22000, GMP).
- Traceability and transparency in origin and ingredients.
- Formulation designed by healthcare professionals, not by marketing departments.
At tres60, we formulate each supplement based on the clinical practice of our doctors, with adjusted doses, bioavailable forms, and scientifically-backed combinations. We don't aim to sell 30 bottles. We aim for you to take the one you truly need and feel the effect.
Conclusion
Supplements are not necessary for everyone. But they are useful for many more people than we usually think, because we live in a context that makes it difficult to cover all essential nutrients with diet alone.
The key is not to supplement by default, but to identify your context: what you eat, how you live, what stage you are in, and what risk factors you have. From there, choose what makes sense. And, above all, choose products backed by science, not marketing.
If you have doubts about whether your case needs supplementation, you can take our test, schedule a free medical consultation or write us on WhatsApp: our doctors will answer you at no cost.
Frequently asked questions
Do supplements replace a healthy diet?
No. Supplements complement, they don't replace. A good diet is still the foundation. Supplements fill specific gaps when the diet falls short.
Is it bad to take supplements without needing them?
In most cases, it's not dangerous, but it is unnecessary and an expense. Some supplements (vitamin A, iron, certain fat-soluble vitamins) can be harmful in high doses without a real need.
How do I know if I have a nutrient deficiency?
Some deficiencies are detected with blood tests (vitamin D, B12, iron, ferritin). Others (cellular magnesium, intracellular omega-3) are more difficult to measure and are assessed by symptoms and context. The recommendation: an annual basic analysis and, if in doubt, medical assessment.
Is it safe to take several supplements at once?
It depends on which ones. Magnesium, vitamin D3, omega-3, and vitamin B12 are compatible with each other. Others can interact with medication or with each other. If you are taking several, it's best to consult a professional.
Why are supplements more common now than decades ago?
Because the nutritional density of food has declined, the pace of life doesn't allow for diet care as before, and because we know more and more about micronutrients and their role in health.
Are supplements regulated in Spain?
Yes. Food supplements are regulated by AESAN and must comply with strict European regulations on composition, labeling, and health claims (EFSA). This does not mean that all products are of the same quality: within legality, there are big differences.
References
- Baladia E, Moñino M, Martínez-Rodríguez R, et al. Uso de suplementos nutricionales y productos a base de extractos de plantas en población española: un estudio transversal. Rev Esp Nutr Hum Diet. 2022;26(3):217-229.
- Wienecke E, Gruenwald J. Nutritional supplementation: is it necessary for everybody? Adv Ther. 2007;24(5):1126-1135.
- Bailey RL, Gahche JJ, Miller PE, Thomas PR, Dwyer JT. Why US Adults Use Dietary Supplements. JAMA Intern Med. 2013;173(5):355-361.
- López-Sobaler AM, Aparicio A, González-Rodríguez LG, et al. Adequacy of Usual Vitamin and Mineral Intake in Spanish Children and Adolescents: ENALIA Study. Nutrients. 2017;9(2):131.
- FAO, IFAD, WHO, WFP, UNICEF. The State of Food Security and Nutrition in the World 2024.
- Allen LH. Micronutrients - assessment, requirements, deficiencies, and interventions. N Engl J Med. 2025;392(10):1006-1016.
- Mayer AB, Trenchard L, Rayns F. Historical changes in the mineral content of fruit and vegetables in the UK from 1940 to 2019. Int J Food Sci Nutr. 2022;73(3):315-326.
- Bhardwaj RL, Parashar A, Parewa HP, Vyas L. An Alarming Decline in the Nutritional Quality of Foods. Foods. 2024;13(6):877.
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