Vitamin D — How underrated this little helper is?

Especially in times of Covid-19.

Woman from behind wearing a hat
Photo by Jason Blackeye on Unsplash

Vitamin D is a little helper which can be supplemented easily. It helps to improve your immune system. In recent studies it shows how it can affect the course of a disease like Covid-19. Older studies also showed that this applied to the flu as well.

Wow — what a powerful weapon against diseases that thing can be. but how much truth is really behind it?

What is vitamin D and why is it so crucial?

Let us dive into a short explanation about vitamins in general. Strictly speaking is vitamin D not a real vitamin. By definition a vitamin is an essential organic compound of the body. It can’t be produced or sufficiently produced by the body itself. It is directly related to the intake within food.

In case of vitamin D is the body however capable to produce 80–90% if the skin is exposed to enough sunlight. The income by food makes only thus 10–20%. This is very essential when it comes to the natural supply of vitamin D.

The more appropriate term would be prohormone, as the vitamin is directly converted into calcitriol. It is the biological active form of vitamin D. This ingredient has a direct impact on the immune system and harden it against infects. It has also a positive impact on the cardiovascular system. In the end it even has influence on your psyche.

So we can see that vitamin D is capable of protecting us against diseases, because it helps our body to build a stronger immune system.

Why does this now affect how often I get sick?

A current estimate assumes that worldwide, 1 billion people have low levels of vitamin D in their blood. This assumptions also indicates that this deficiencies can be found in all kind of ethnicities and age groups.

So don’t be one of them and if you are keep reading.

Why is that and how can I recognize a deficiency?

As we learned earlier our body produces vitamin D if our skin is exposed to enough sunlight. So it typically depends on how much time you spent outside. In these days this is easier said than done. Our modern lifestyle doesn’t really do its part.
For example I work from 9–5 in an office. In this time range I’m barley outside and catch sunlight. Especially in winter when the days are shorter anyway. In my case it was clear to me that my vitamin D levels could be lower than recommended.

If you don’t want to rely on just your belly feeling, you can arrange a blood test with your doctor. Then you can be really sure.

Supplementing vitamin D properly?

Sure the best way to supply your body with this crucial vitamin, is by catching a good amount of sunlight every day. Even if your skin is covered it can produce enough vitamin D. If you can build a routine around getting outside more often, you will most likely have no problem whatsoever.

It is already enough here to spent 30 minutes in midday sunlight.

As I said this isn’t that easy in winter days. But we can help ourselves by using vitamin D supplements. You can order a yearly ration for about 20 bucks. The only advice I can add here is that it is advisable to look after a supplement which includes vitamin K2 already.

I know it sound odd — another vitamin for taking in the first one.

But vitamin K2 is essential when it comes to supplementation, because it activates proteins which makes vitamin D for the body usable. Without this extra vitamin our body can’t benefit from the pure vitamin D supplementation itself. So see vitamin K2 as a kind of courier.

The National Institute of Health recommends a daily intake in between 600 and 800 IU (International unit).

Sure it would be desirable that everyone get access to those for free. But our society needs a little bit more enlightenment about this topic. In the UK for example 2.5 million people will be offered free supplements this winter. They try to address issues in context of Covid-19. In my opinion that should be done worldwide. But let’s see why this is so.

Let’s talk about Covid-19

A lot of recent studies showed that the deficiency of vitamin D can have a direct impact of the course of Covid-19. It also affects mortality in a dramatic way.

In one of the first studies conducted in Spain they found out that nearly 82.2% of the diagnosed people suffered from a deficiency in vitamin D. The group without being diagnosed with Covid-19 there was just a deficiency of 47.2%.
Another retrospective study performed in France showed even a connection in mortality. The control patients had no intake of vitamin D supplements before or after the diagnose. This group had a mortality of 55.6%.
The other group got a supplementation of 80.000 IU in total before and after the diagnosis. This group just had a mortality rate of 17.5%.

These examples show positive effects on patients during a course of Covid-19. There are a bunch more studies that showed similar results. There is even an internet site that only deals with this specific topic ( They collect all studies that are related to Covid-19 and vitamin D.


It is always advisable to take care of your health. In this case we can do something proactively. Taking care of our vitamin D blood levels.

Covid-19 showed us once more that it can be very important to life healthy. Diseases will always have the most impact on the weak and old. So we have to care more about them. Carrying can also mean that we start to give them advise on certain topics.
We already know how important it is and we have to communicate about it even more.

Thanks for reading. Stay safe and healthy.


System Engineer @Fraunhofer on that behalf I’m interested in state of the art tech. Otherwise I’m totally into martial arts and fitness.

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