Why vitamin D is one of the best supplements to help win the war against winter bugs

In the UK, the National Institute for Health and Care Excellence (NICE), suggest that around 10 million people maybe deficient in vitamin D.  So why is it important, how do you get it and how do you know how much to take?

Why vitamin D?

We need vitamin D for our immune system to function in the right way.  This is because immune cells have vitamin D receptors on them and when it is absorbed into the cells it acts as an immune modulator, providing a protective effect against infections and supressing the replication of some viruses.  These immune cells are mostly in the gut and it is thought that vitamin D may also support the integrity of the lining of the gut.  There is also a suggestion that vitamin D may provide protection against other conditions and you can read more about that here.  In other studies, vitamin D deficient individuals were found to be at higher risk of COVID-19 infection as compared to vitamin D sufficient patients.

How do I get vitamin D?

Our bodies cannot make vitamin D without sunlight and food (but only in small amounts), and in supplements.  Vitamin D is fat-soluble, which means you need to eat fat to absorb it.  Foods include oily fish, organic dairy, beef liver, mushrooms exposed to sunlight, tofu, fortified milk products, fortified cereals and eggs but we  have to eat an enormous amount to get anyway near the recommended minimum amount like 3kg of cheese, several cans of tuna and 8 eggs!.  In the summer when our skin is exposed to sunlight, 90% of our total vitamin D comes from sunshine and we are likely to be making enough.  However between October and end April (when our shadow is longer than our height in the sunshine), we need to find it elsewhere.  In food and supplements, there are two types of vitamin D; D2 which is found in plants and D3 found in animal products.  Our body makes D3 which is its preferred form, so it is important if you supplement to purchase in D3 form.  Fortified foods are usually supplemented with D2.

How do I know how much to take?

An optimum level of vitamin D is between 75nmol/L and 100nmol/L.  You can get an at-home test for £29 https://www.vitamindtest.org.uk/ and you can calculate how much you may need here.  

Did you know that NHS and Public Health England recommend that anyone over 12 months old should take a supplement at a minimum of 400iu of vitamin D per day from October to March which, by the way is barely enough to maintain current levels? Did you also know that the US which is at a lower latitude than the UK (except Alaska), recommends higher amounts and with an upper tolerable limit?

It is always better to tailor the dose to suit you by testing your current levels, however if you are unable to take a test, a top up dose over the winter is 2,000-3,000 iu’s as a daily food supplement is sufficient and at this level is unlikely to lead to a too high a level unless your D3 is already too high, which is rare.  Note this is much higher than the NHS recommendation.  There are infant and junior supplements at a smaller dose also available.  BetterYou offer good quality highly absorbable supplements.  Unless you are taking blood thinners, I would always recommend taking vitamin D3 with vitamin K2.  This is because the current research shows that vitamin K2 ensures that the calcium transported by the vitamin D is absorbed by your bones where it is needed.

Tracking your vitamin D absorption via sunlight.  There is a wonderful free app for this – it is for the summer than winter https://dminder.ontometrics.com/

Lack of sleep, stress, sugar, alcohol poor diet can deplete your immunity and no amount of supplementation can compensate for poor lifestyle.  So always consider supplementation as part of a wider lifestyle approach to winter wellness.