Why Vitamin C and immunity boosters are not what you need: Liver Doc explains

Do you need a booster?

Here is the part the advertisements never mention: you do not actually want a ‘boosted’ immune system. An immune system turned up too high is exactly what makes people miserable. It is why we get allergies and autoimmune diseases – like an army turning on its own citizens. In severe infections, patients often die not from the germ but from their own immune system overreacting, what is called the infamous cytokine storm. The goal is never to be “louder”, but “smarter and well-regulated.”

Do immune boosters at least do something?

Vitamin C is the patron saint of this myth. Decades of careful trials later, we know better: routine vitamin C does not stop you catching colds and at best shaves a few hours off the one you already have. Zinc and Vitamin D supplements just drain your wallets. If immune boosters worked as advertised, hospitals would stock them next to antibiotics. But instead, supermarkets place them next to the chewing gums and candies at the checkout.

At one point, “natural” quietly stops meaning “harmless.” In America’s drug-injury registry, herbal and dietary supplements went from causing 7% of reported liver-injury cases in 2005 to 20% today – a more than five-fold rise, driven largely by exactly the products marketed for immunity: turmeric and green tea extracts, ashwagandha and multi-ingredient “immunity blends.” By buying an immune booster, you are inside an unlicensed trial you never consented to. Many of these products are unregulated, mislabelled or contaminated; you often have no real idea what is inside your immunity supplement. And the quietest harm is behavioural. Feeling “protected” by an immune booster in a bottle is exactly what the wellness industry wants you to believe, without evidence.

The good news is that you can spot this fraud without a medical degree. Real immunology is specific – it names the cell, the antibody, the pathogen. Marketing is generic and vague: “supports immunity,” “strengthens defences.” Ask one question of any product: boost which part, and measure how? If there is no answer, there is no science. Anything that claims to strengthen your entire immune system against everything at once is selling you a feeling, nothing functional.

How to strengthen your immune system then?

But a genuine, proven way to upgrade your immune system does exist. It is not inside a supplement. It is a vaccine. Vaccines do exactly what every marketed fraud booster pretends to – they teach your adaptive immune system to recognise a specific dangerous germ in advance, and to remember it. Vaccines are among the greatest achievements in human history. Small pox, which killed hundreds of millions, has been wiped off the planet. Polio, which once paralysed hundreds of thousands of children a year, has been pushed to a tiny handful of cases. Measles, diphtheria, tetanus, whooping cough and hepatitis B have been crushed wherever vaccines are used.

The US declared measles eliminated in 2000. By 2025, (no) thanks to “Make America Healthy Again” cultists, with childhood vaccination rates slipping below the safety threshold, America logged its worst measles year in three decades – a live demonstration, playing out in real time, of what “unboosted” immunity actually looks like at population scale.

So, look after your immune system: adequate sleep, eating whole foods, aerobic activity, avoiding tobacco and alcohol and getting vaccinated for age. Your immune system does not need a supplement. It needs a good teacher – and we already invented one, the vaccine.

(The writer is public health activist, clinical scientist in hepatology at Rajagiri Hospital, Kochi, Kerala and author of The Liver Doctor, published by Harper Collins India)