Dietary supplements have quietly become part of everyday life for millions of people — from multivitamins and vitamin D to herbal products, immunity boosters, and protein powders. Their popularity has grown steadily over the past two decades, but the COVID-19 pandemic gave the supplement industry an even bigger push.

People were worried about the virus, which was novel, as the name suggested, as the vaccines were not yet widely available, and many wanted to “boost” immunity, so they turned to supplements for protection. Sales rose in several parts of the world, even though little evidence showed that most of these products could prevent or treat COVID-19.

That surge also raised an important question: if supplements can help in some situations, can taking them unnecessarily be harmful? Research shows that while certain supplements have established benefits for specific deficiencies and conditions, others can cause side effects, interact with medicines or, when taken in excessive amounts, even become toxic. The growing supplement culture raises a simple but important question: who actually needs them, and when are we taking more than our bodies need?

We'll break a few myths. We speak to Dr Aijaz Ilmi, Senior Consultant & Head, Preventive Wellness & Metabolic Diseases

Pacific OneHealth

Myth #1: Everyone should take them

No, they are not for everyone.

“Supplements make sense when there is a demonstrated deficiency, predictable nutritional gap, or medical reason for increased requirements.

Examples include iron, vitamin B12, or vitamin D deficiency; pregnancy-related folate needs; restrictive or vegan diets; malabsorption disorders such as coeliac disease, gastrointestinal disease, or surgery. Certain medications and particular stages of infancy and childhood,” Dr Aijaz Ilmi says.

A trained medical provider can evaluate patients through blood tests or their medical history.

People with restricted diets may need more supplements. Vegans, for instance, often need vitamin B12 and may also need nutrients such as iron, calcium, zinc or vitamin D. Those who have had bariatric surgery or are taking GLP-1 drugs may also need extra nutrients because they are eating less.

Pregnant women are generally advised to take prenatal supplements containing folic acid, while older adults may need additional vitamin B12, calcium or vitamin D. Certain supplements also have established roles in conditions such as osteoporosis and age-related macular degeneration.

For everyone else, a good-quality multivitamin is unlikely to cause harm when taken appropriately, but it may simply be unnecessary. If your diet is varied and balanced, most of the nutrients your body needs should ideally come from food.

Myth #2: If they are natural, they are safe

Dr Ilmi says no. “Arsenic, tobacco and poisonous mushrooms are natural too.

Herbal and plant-based supplements contain active compounds that can cause allergic reactions, liver injury and gastrointestinal symptoms, or interact with medicines such as anticoagulants, diabetes and blood-pressure drugs, and sedatives.

Children require particular caution because dosing, product purity and long-term safety data may be limited. Supplements also do not necessarily undergo the same pre-market testing for efficacy and safety as prescription medicines,” he says.

“Herbal” describes an origin; it does not certify safety.

Unlike medicines, dietary supplements are regulated as food in the US and are not routinely tested by the FDA for safety, effectiveness or contents before they reach the market. Same is true in India as well. That means the quality and actual dose can vary between products. Some supplements have even been found to contain contaminants, including heavy metals and toxins.

Supplements can also interfere with medicines. Vitamin K, for instance, can reduce the effectiveness of some blood thinners, while St John’s wort can interact dangerously with antidepressants. The safest approach is to tell your doctor about everything you take—including supplements—so they can check for potential interactions.

Myth #3: You can take them and not worry about your diet

Dr Ilmi says that, for most healthy people, food comes first.

A varied diet provides protein, essential fats, vitamins, minerals, fibre and thousands of bioactive compounds in combinations no multivitamin can reproduce.

Supplements are useful when food alone cannot reliably meet requirements—for example, with confirmed deficiency, restricted diet, malabsorption, pregnancy, specific infant needs, certain chronic diseases or medications, or another clearly identified increased need.

Children illustrate the principle. Vitamin D recommendations depend on age and intake, and some breastfed infants need iron based on age and circumstances. These are targeted recommendations—not a reason to give every child a cupboard full of gummies.

Myth #4: More is better

More is not necessarily better when it comes to supplements. In some cases, taking a higher dose than the body needs may do more harm than good.

Certain nutrients can accumulate or cause problems when taken in excessive amounts. Too much vitamin B6, for instance, can damage nerves. High doses of omega-3 supplements have been linked to an increased risk of irregular heart rhythms in some people, while excessive vitamin A can harm the liver. Too much vitamin D can also have adverse effects, including an increased risk of fractures.

Doses depend on factors such as age and sex.

Another issue with taking several nutrients together is that the body may not absorb all of them efficiently. Minerals such as iron and calcium can compete with each other for absorption. The body also has limits on how much it can absorb at one time.

Myth #5: They can fix everything

Some supplements do have solid evidence behind them. Magnesium, for instance, can help relieve constipation, while creatine supports the muscles’ energy supply. Omega-3 supplements to complement what she gets from food.

But the evidence is much weaker for many popular products. Research says Melatonin, for example, may help people fall asleep slightly faster — by an average of just four minutes.

More importantly, supplements should not replace proper diagnosis or proven treatment.

Dr. Ilmi says one needs to follow a cycle. Food first- assess risk- test when indicated-identify the gap-replace what is missing-Use the right dose-Reassess.

“Supplements can be excellent medicine when they correct a genuine need. Without one, they may produce expensive urine—or occasionally, expensive problems,” he says.

“ Don’t supplement because an advertisement found you. Supplement because your biology gives you a reason,” he adds.