Vitamins: friend, foe or fable?

‘You’re looking sickly, you need some sunshine!’, ‘Eat some oranges, that will hold off the cold.’ We’ve all heard it before and although these ideas might sound a bit like old wives tales, it turns out there’s some basis to this ‘health advice’ and it all comes down to vitamins. So what are they really? Vitamins are very small molecules that help your body function, but they also help to protect you from getting sick.

Fruit and vegetables: a great source of vitamins. Sourced via Flickr.


How does my body protect me from getting sick?

An important feature of being strong and healthy is immunity to infection. I think we can all agree that most days we enjoy not having a sniffly nose, a sore throat or diarrhea from bugs that are we are constantly exposed to every day at home and at work (yes they’re all over your phone too). For this we have to thank our immune system – the body’s army against infection. When your immune system is working well, millions of white cells in your blood and throughout your body are happily defending you by destroying dangerous bugs (while the red ones are busy carrying oxygen). What we are understanding more these days through studying the function of these cells is that there are many different types, and every organ in your body contains specialised cells which have been taught how to fight and kill particular bugs. For example, the cells in your skin are good at recognizing and killing Golden Staph, a well known bacteria found commonly in hospitals that can live on your skin and infect through cuts or scratches. In contrast immune cells in your stomach and intestine are very good at destroying dangerous strains of E.coli – a bacteria that commonly makes people sick because it contaminates food or water sources.


So how do vitamins help?

Well the trick here is how your immune cells know which parts of the body are under attack from which bug and guess what gives them some pretty good clues? Vitamins. Recent research has shown that a type of white blood cell called a dendritic cell can sense Vitamin A in the gut from all the fruits and vegetables you eat and this tells the cell it will need to be good at fighting bugs like E.coli, where as dendritic cells in the skin love swimming around in Vitamin D which is produced by your skin when you are outside and exposed to warming rays of sunshine. The skin dendritic cells understand Vitamin D as a signal that Golden Staph might pop up at any time and to be ready to fight it. This education of immune cells by the vitamins in their environment is a very powerful way that your body has learnt to defend against the many different bugs that you encounter every day.

Cartoon representation of a dendritic cell: image via Flickr


So what happens if you’re not providing your body with the vitamins to teach your cells how to fight? Well, they really struggle to defend your body as well as they should; it’s like leaving your army without a commander and this can leave you more vulnerable to infections from bugs that you normally wouldn’t even notice because your cells kill them before they make you sick.

So eat some extra veggies for lunch today and go for a walk in the sun this afternoon to give your personal army a little boost!!