Why Do I Need Vitamin D?

We probably all have an idea where Vitamin D comes from. 'The Sun' you may say, or maybe you think of ads for various dairy products pointing out that these contain Vitamin D.

While both of these are essentially true (your body actually just uses the Sun to turn 7-dehydrocholesterol, a type of cholesterol, into this useful vitamin!) they don't explain why you need vitamin D and they don't help us to know if we are getting enough.

Vitamin D is very important in keeping our bones healthy. It helps absorb calcium, the main building material of our bones, from our gut so we make the most of the calcium we get from our food. Vitamin D also helps us hold on to the calcium we have already absorbed when it works on our kidneys.

Vitamin D is also needed in order for our immune system to function properly. Vitamin D encourages the cells of the immune system to function properly and a deficiency in Vitamin D has been linked with a weaker immune system and a higher chance of a range of diseases called 'autoimmune' diseases. These include conditions such as arthitis and psoriasis.

The fact that vitamin D is important for our immune systems and comes from the Sun certainly can't help all the colds and flus we get during the winter! It is a case of very bad timing that during the winter when we find ourselves stuck inside together, out of the cold, we are getting the least amount of natural vitamin D. This can make us more likely to pick up the bacterial and viral infections we see at this time of year.

It is for this reason that the HSE recomends that most people supplement with Vitamin D from Halloween to St. Patrick's day. 10-15 micrograms is a good marker to aim for but we will be sharing more detailed information on vitamin D supplementation here in the near future.