Portugal's supplement boom: Why half of adults take them

Half of Portuguese adults now rely on dietary supplements, survey finds

More Portuguese Consumers Turning to Dietary Supplements

More and more Portuguese people are taking dietary supplements. According to a survey conducted by consumer rights organization DECO PROTeste and released in November 2025, one in two Portuguese adults aged 18 to 74 has used supplements in the past two years. Vitamins, proteins, and minerals top the list of preferences, with respondents citing increased energy, combating fatigue, boosting immunity, and improving athletic performance as their main reasons for taking them. But do we really need them?

Who Might Benefit Most?

Though sold in pharmacies, dietary supplements are not medicines—they are not intended to cure, treat, or prevent diseases or symptoms. Instead, they are classified as food products, which is why they are also available in supermarkets and online stores. Science confirms that certain supplements can offer therapeutic or preventive benefits, but their effects are not universally advantageous.

"Groups with specific or heightened nutritional needs—such as the elderly, pregnant and breastfeeding women, infants and children, individuals with chronic inflammatory or autoimmune conditions, those on restrictive diets or with poor nutrition, and people with limited sun exposure—are most likely to benefit from supplementation," explains nutritionist Ana Afonso Martins. "As we age, the body's natural production of antioxidant nutrients declines, which can weaken cellular protection. From the age of 40, reinforcing support with selenium, zinc, and coenzyme Q10 may be beneficial," she adds.

For healthy individuals, "a balanced diet may be sufficient," but it "doesn't always guarantee optimal micronutrient levels," notes Bernardo Pessoa, a general practitioner specializing in integrative and sports medicine. "In certain circumstances, supplementation can help prevent deficiencies and optimize physical and cognitive performance," he says.

According to nutritionist Ana Carolina Soares, the goal of supplementation in healthy people is to prevent deficiency-related conditions (such as scurvy or rickets), enhance metabolic function, and promote cellular longevity. "In an ideal world—with a perfect diet, restful sleep, no stress, and adequate sun exposure—supplements might be unnecessary."

Common Nutritional Deficiencies

Even those with a balanced, varied, and complete diet may still experience nutritional gaps. As Ana Afonso Martins points out, several factors can undermine nutrient intake, including soil and food quality, impaired nutrient absorption, drug interactions, and insufficient sun exposure.

Iron, magnesium, vitamin D, selenium, and omega-3 fatty acids are among the most common deficiencies in the population, experts say. "Vitamin D is particularly difficult to obtain through diet alone, as it primarily depends on sunlight-induced skin synthesis. Omega-3s, meanwhile, require regular consumption of fatty fish, which is often lacking in modern diets," explains Bernardo Pessoa.

The Risks and Myths of Supplementation

However, "supplements are not a substitute for a healthy diet—they are meant to complement it," stresses Ana Afonso Martins, who emphasizes that the need for supplementation should be assessed by a healthcare professional to avoid self-prescription, overuse, or health complications. When taken without proper guidance, supplements can pose risks, including toxicity, significant adverse effects (often due to overdosing), and interactions with medications, which may compromise their efficacy and safety.

There are even a few myths surrounding dietary supplements that need to be debunked. One of them, explains nutritionist Ana Carolina Soares, is the belief that supplements can replace the consumption of fruits and vegetables. This is false because "supplements lack the fiber and the complex phytonutrients found in whole foods." Another misconception is the idea that "if it's natural, it can't harm you"—but as Soares points out, "the fact that a substance is natural does not rule out side effects or interactions with conventional medications." She also notes that, contrary to popular belief, not all supplements are created equal.