The Vitamin Paradox: why both health and illness boost our misplaced trust in supplements

Supplementing diets with vitamin pills has become a popular practice, but the evidence behind their effectiveness is increasingly shaky.

NS

Sign Up

Get the New Statesman's Morning Call email.

It was the humble vitamin that eventually tarnished the reputation of Nobel Prize-winning chemist Linus Pauling. In the Seventies, towards the end of his long and broad-ranging career, Pauling became obsessed with the effect of taking dietary supplements – Vitamin C, specifically. Having pioneered prestigious research into everything from DNA structure to nuclear disarmament, the highly-respected scientist's legacy fell flat when he was first introduced to the world of vitamins by a fellow chemist.

This chemist held the notion that ingesting 3,000mg of Vitamin C per day would be an effective way of extending your lifespan by decades. Pauling was sold. He reported feeling healthier, upping his daily dose as a way to combat illness, and wrote a book called Vitamin C and the Common Cold. His book encouraged the public to follow in his footsteps by taking 3,000mg of Vitamin C per day (an amount far higher than the daily recommended dose). His clout and reputation in the science world led millions to follow his vitamin protocol.

In the Seventies, his claims grew wilder. According to Pauling, increased Vitamin C intake would not only cure the common cold, but also cancer, writing that, “my present estimate is that a decrease of 75 per cent can be achieved with Vitamin C alone”.

At this point, many major scientists stopped backing Pauling, understanding just how damaging his advice could be to both their reputations and the health of the public.

Scientists took to disproving Pauling’s theory on Vitamin C by undertaking a number of wider studies. One such study saw scientists at the University of Maryland administer vitamin C to volunteers infected with a common cold virus, just as prescribed by Pauling in his book. The results? None of the volunteers recovered from the cold. A larger study gave 3,500 volunteers Vitamin C, to no effect. It has been a recurring trend, with study after study showing little change to people’s health when given the vitamin.

For scientists, Pauling’s idea that Vitamin C could cure cancer had to be challenged. A study done by the Mayo Clinic saw Vitamin C given to 150 cancer patients, again, to no effect. Repeated studies also demonstrated this, with some in fact showing that taking the supplements could even increase the risk of mortality. A study in 2004, which involved around 170,000 people taking vitamins A, C, E and beta-carotene, showed that the vitamins seem to “increase overall mortality”.

Vitamins and minerals, when ingested via food, are a crucial part of a healthy diet. The UK’s Eatwell Guide today gives recommendations of calorie intake, dietary composition and hydration, and serves as a day-to-day nutrition guideline for the average male or female adult hoping to lead a relatively healthy life. Recommended daily allowances for vitamins and minerals generally find themselves attached too, offering everyone the chance to plan their diets with pinpoint precision.

With the rise of chronic illnesses such as obesity and the increasing prevalence of heart disease, concerns have emerged that these daily recommendations are incomplete, obsolete and in need of reform.

In response, hoards have taken to their local pharmaceutical stores, raiding the shelves for bottles containing supplementary vitamins in the hope that loading up on them will provide a health safety net: A, B, C, D, E, multivitamins, ZMA’s, calcium, and iron are just some of the many adopted. Some go as far as saying that “a synergistic blend of essential nutrients” will make you an Ultra Man or Ultra Woman.

Logic dictates that the more you supplement your diet, the healthier you will inevitably be. Logic in this case, however, seems a little flawed, and it’s this so-called logic that was perpetuated by Pauling.

For a number of different countries, vitamin supplements were introduced in the early 1900s, at a time when diseases related to vitamin deficiencies (for example, rickets) were prominent, necessitating the introduction of supplements to fill the void created by limited sources of fruits and vegetables. With time, recognition of the consequences of vitamin deficiencies meant a number of organisations and food companies went to work to fortify foods, ensuring that a typical diet was never lacking in essential vitamins and minerals.

Vitamin deficiency diseases now occur at a reduced rate of incidence; when everything from your cereal and milk to your bread and butter is fortified, there should be less of a concern about whether you are reaching your daily vitamin and mineral quota.

However, the success of food fortification has led to hyperbole about the effectiveness of vitamin supplements, exaggerating claims about their benefits to encourage an increased uptake, while taking advantage of people’s beliefs that a few pills offer a quick-fix, cure-all solution to their ailments.

For those who continue to support vitamin supplementation in the face of evidence, the antioxidant property they have is touted as a reason to continue taking them. The theory goes that antioxidants are needed to balance the oxidation that occurs within cells – oxidation being a potentially negative thing if it isn’t counterbalanced as cell-damaging by-products called “free radicals” are formed. By taking vitamins, you’d be at a reduced risk of damage from free radicals, according to the proponents of the supplements.

Dietary recommendations of fruit and vegetables are there partly to contribute to this balancing act of free radicals versus antioxidants. Vitamins and minerals assimilate much more effectively when sourced from food, and so it is likely that additional supplementation on top of this causes a severe imbalance.

Vitamin supplements cannot significantly protect against disease and they certainly can’t remedy cancer. It is worth noting that though most supplements are ineffective, a recent phenomenon of vitally low Vitamin D levels among Europeans and North Americans has meant that supplementing with pills can create a positive change.

To really make progress and improve public health, it is crucial that myths are dispelled, and we begin to place a little less faith in magic cures and a little more faith in the food we eat.