Good morning, my name is Stelios Pantazis, I am a doctor, I specialize in medical nutrition

and metabolic disorders and today I would like to say a few words about vitamin D.

Something that my patients, my clients and the people who to me keep asking

is: "How is it possible that everyone is deficient in vitamin D?"

Anyone who has had a vitamin D test tells me, "Do you know what? Stelio,

I was tested for vitamin D and I'm deficient. "I tell him," Okay, you're not telling me something new.

Anyone who takes a vitamin D test and does not take vitamin D supplements is deficient.

And everyone always asks me, "Why? Why are we all deficient in vitamin D?"

"What is this thing? This vitamin that is so necessary and does not exist anywhere?".

The answer is simple.

First of all, vitamin D is extremely important, which is why it is also called vitamin

since the first component of the word is vital, that is, important for health

so it is necessary to take it in part from

our diet. However, it is partly synthesized in our skin.

Now this is where the problems begin.

In order for Vitamin D to be synthesized in the skin, our skin must be exposed to intense sunlight

to an extensive part of our skin, daily, or at least very systematically

and secondly, after the exposure we should not wash.

Now, this thing is almost impossible!

Or at least it's impossible 360 ​​days a year.

In other words, one needs to be exposed to the sun all the time wearing only, say, one's swimsuit,

e.g. during the summer. During this time ona has to be exposed to sun extensively for this to happen, and this

is not danger-free, and at the same time not wash almost all day

Then indeed, the vitamin D that will be produced will be sufficient for a few

days. We can say that if we go on vacations 2 weeks at the seaside we will produce enough

Vitamin D to store in the body us for a long time, but not for the whole year.

If there is sun outside and I am in the office, dressed, covered in clothes, the sun

is filtered through the windows and so no vitamin D is synthesized at all!

When I'm in the car and it's sunny outside and I'm in the car with clothes or even wearing a

short-sleeved, again vitamin D is not synthesized and certainly not in sufficient quantities

In fact, when the color of the skin darkens from sun exposure, production

of vitamin D is decerased once again.

So in no case can we say that from sun exposure we can

have sufficient vitamin D synthesis.

So it means that we need to get a lot of it from our diet.

That sounds reasonable. But here the problems begin.

Because vitamin D, as synthesized in humans from sun exposure, is also synthesized in the

foods we eat.

Both plants and animals produce vitamin D when exposed to the sun.

Vitamin D3 is produced by mammals and vitamin D2 by plants.

Both are sufficient and usefull for us.

The problem is that most of the plants we eat are produced in greenhouses

therefore, they do not synthesize a sufficient amount of vitamin D because ultraviolet radiation does not pass

in the greenhouse in order to increase the production of vitamin D in plants, and

on the other hand, concerning mammals used for food, they are most of the time they are protected in stables.

So they are also not exposed to the sunlight in order to produce vitamin D.

The result is that all of our foods, both plant and animal, are poor in vitamin D.

The result is that we are deficient and forced to take it as a nutritional supplement.



That's why the guidelines recommend 2-4 thousand units of vitamin D3 every day for everyone.

Thank you very much!