Going back to basics - what actually are vitamins and minerals?

For most of us vitamins and minerals are that vague group of compounds that we dimly remember from school as being somehow essential for our health, but that are most frequently sighted in the supplement aisle of our local pharmacy, or on the back of that expensive anti-aging cream you bought promising miracles…

But why do we need them? What do they do? And what’s the deal with supplements?

THE MICRONUTRIENT NEED TO KNOW

Everything we eat broadly falls into one of two camps in Nutrition World. The macro nutrients (fats, carbohydrates, and proteins), and micro nutrients, aka vitamins and minerals. Here’s a quick run-down of the need-to-know:

·       There are 13 vitamins, and 17 minerals that we know we need as part of our daily diets.

·       Vitamins and minerals are called micronutrients because we don’t need them in large amounts, like we do the macronutrients. Instead, we need them in such small amounts that they’re often quite hard to visualise. A microgram anyone?!

·       They’re essential because our bodies can’t make them in large enough quantities themselves, so we have to get them from our diet.

·       They’re not a source of energy or fuel and contain no calories. Instead our bodies use micronutrients as co-factors and co-enzymes to help them carry out the day-to-day grind of running a human body. DNA replication? Metabolising food for energy? Forming your bones and skeleton? All done with a helping hand from various vitamins and minerals.

·       Minerals are different to vitamins (and in fact, most living things) as they are inorganic substances found in rocks and ore that have slowly worked their way into our diets via soil and plants. They are single elements, so copper, iron, and so on.

·       Vitamins in contrast are organic compounds, so contain carbon, meaning that they’ll burn if you for whatever reason choose to set fire to your food.

·       Fun fact – because of this, mineral amounts in food were originally measured by combusting food in a furnace and measuring the resulting ash, while vitamins proved much harder to identify and are largely 20th century discoveries.

A bit of history and more on the confusing name situation

The term ‘vitamin’ (from ‘vital amine’) was coined by Casimir Funk in 1912 when he isolated thiamine, or vitamin B1. It was an unusual name even then, but has stood the test of time despite the fact that not all vital substances turned out to be amines (an amine is an organic form of nitrogen). However, Funk was not the only researcher working on the unknown substances we know today as vitamins. Funk actually built on the work of several scientists, including Eijkman, whose work in Indonesia on chickens in the 1870’s led him to identify the fantastically named ‘beriberi’ disease as a deficiency illness and not - as was thought at the time – a bacterial one. So although citrus (ie. Vitamin C) had been used for centuries by sailors to ward off the dreaded scurvy, vitamin B1 or thiamine actually pipped everyone else to the post in being the first vitamin officially discovered.

Because little was known about their chemistry, the naming of the individual vitamins initially presented a problem. As the vitamins became differentiated, they were designated by letters of the alphabet, usually in order of their discovery. The substance originally known as vitamin B became further subdivided into many chemical substances that were called vitamin B1, B2 and so on. As the chemical identity of the different vitamins was established, chemical names gradually replaced the earlier designation for specific chemical compounds found to have vitamin activity. However, the letter system is used in referring to groups of closely related substances that show common vitamin activity. For example, we talk of ‘vitamin A’ and ‘Vitamin E’ activity when really these are groups or families of chemically related compounds.

THAT’S GREAT, BUT HOW DO I KNOW HOW MUCH OF EACH MICRONUTRIENT TO TAKE?

In the UK, the recommended intakes for vitamins and minerals is called the RNI. That’s the Reference Nutrient Intake if you really want to know, more commonly referred to as the RDA (Recommended Dietary Allowance) on food and supplement labels. This is calculated so that if we hit the RNI for any micronutrient, 97.5% of the population will have had enough.

That said, one size does not fit all in terms of how much each of us needs of any vitamin or mineral. How much you need depends on your age, gender, health status, and whether you’re pregnant or breast-feeding. The A to V lists the requirements for healthy adults over the age of 19 in the UK, but if that’s not you then take a look at this guide from The British Nutrition Foundation, or The Institute of Medicine if you’re in the US.

And what about supplements?

While a balanced diet is all most of us need to get the right amounts of vitamins & minerals, the problem is that a typical diet these days is actually not all that balanced, and often low in foods such as fish, dairy, and anti-oxidant rich fruit and veg.

In the UK, only 30% of adults meet the “5-a-day” recommendation according to data published by the government in 2014, and average consumption of oily fish was well below the recommended one portion (140g) per week in all age groups. And the trend is a global one. In 2011, the Journal of Nutrition published a report entitled “Foods, fortificants, and supplements: where do Americans get their nutrients?” Without supplements, and enriched and fortified products, the authors estimated that 100% of Americans would fail to meet the average requirements (EARs) for vitamins D, E, C, A, B1, B6 and B9.

The problem however,  is that isolating vitamins and minerals and serving them up in supplements as megadoses, is not a sure-fire route for attaining good health either. In fact, several randomised controlled trials (the most reliable type of experiment) have shown that the antioxidant micronutrients can actually act in very different ways to how we’d expect when taken in large amounts as synthetic supplements.

While there absolutely is a role for supplements in certain circumstances, the fact remains that most people who take supplements are precisely the ones who least need them. According to research by the Food Standards Agency (FSA) in 2008, nearly a third of people in the UK take some vitamin, mineral or dietary supplement on most days, and about 15% of us report having taken a “high dose” supplement in the last 12 months. Supplement companies are big bucks in other words.

So what should I do?

Although a varied and balanced diet is the recommended way to get your micros, this isn’t always possible. The two big exceptions?

·       Vitamin D. Everyone in the UK should take a daily dose of 10 Ug a day, as this vitamin is hard to get in adequate amounts from diet alone (unless you fancy eating 10 eggs everyday), and there ain’t enough sunshine most of the year for us to soak it up that way.

·       Vitamin B12. This vitamin is only found in animal products. So vegans will need a supplement.

At the A to V I believe your best bet is to eat a varied and healthy diet, avoid taking megadoses of anything, and consult credible sources such as dieticians, your GP, or the BDA and BNF websites if you think you should be taking a supplement.

Additional references

Fulgoni, V.L., Keast, D.R., Bailey, R.L. and Dwyer, J., 2011. Foods, fortificants, and supplements: where do Americans get their nutrients?. The Journal of nutrition, 141(10), pp.1847-1854. Available here.

Klein, E.A., et al., 2011. Vitamin E and the risk of prostate cancer: the Selenium and Vitamin E Cancer Prevention Trial (SELECT). Journal of the American Medical Association, 306(14), pp.1549-1556. Available here.

NHS Choices. (2011) Supplements, who needs them? A behind the headlines report. Available here.