Vitamin D. From vitamin to hormone!

With the arrival of daylight saving time we will be able to enjoy more hours of daylight in the day, but despite this, if we have not done our homework in the winter months (with fewer hours of sunlight) we may present a deficiency of a vitamin as multifaceted as vitamin D, it can even be found also known as hormone D. For the topic we bring today, it is interesting.

At SMART NUTRITION we want to talk to you about the importance of vitamin D in relation to sport and in particular in Crossfit, why it is so important, where we can get it, if it is necessary to supplement it and also offer some advice and tips to optimize its levels in our body.

What is vitamin D?

It is a fat-soluble vitamin that is essential for our body. We have two options for obtaining it. These are sun exposure and food. Thus, there are two forms of vitamin D that are mainly interesting for us, which are known as vitamin D2 or ergocalciferol and vitamin D3 or cholecalciferol.

The main difference is the way to obtain it:

While we get vitamin D2 from plant-based foods, we get vitamin D3 from animal-based foods and sun exposure. We can also use functional or enriched foods, as well as supplements or drugs.

Although they may be structurally different, their effect on the body is identical. Virtually all the pre-vitamin D that we obtain to carry out all the reactions that will lead us to the active form of vitamin D is obtained from sun exposure to ultraviolet B rays. It is in the skin where we obtain vitamin D3 or pre-vitamin D through cholesterol precursor molecules (7-dehydrocholesterol), which through its passage through the liver first to obtain 25-hydroxy-vitamin D and later through the kidneys, we obtain the active form of vitamin D or 1,25-Dihydroxy-vitamin D. In summary, it is known as "vitamin D metabolism" (reference) .

Vitamin D acts through VDR receptors and what is striking is the number of these receptors that are distributed throughout the body, which makes vitamin D a very complete molecule of action, acting on calcium and phosphorus homeostasis and on the immune system to muscular systems and cardiac muscle. All these action targets have a very close relationship with sports performance (reference 1) (reference 2) .

Regarding the main way of obtaining vitamin D, the recommendations indicated by some studies seem not to be achievable by a large part of the population , mainly due to the pace of life.

If our work is indoors, we travel by car or public transport and most of the year we do the WOD inside the box or indoors, it is very likely that our vitamin D levels are not optimal as we spend much of our time in the shade or exposing ourselves through a glass or window.

Given the multiple functions that vitamin D has in our body, we should pay special attention to our blood levels and consider reinforcing them with a supplement, especially if we also practice sports regularly where vitamin D needs may be greater than in the general population.

How do we know our vitamin D levels?

Through a blood test we can know the levels of its inactive form or precursor (25 hydroxyvitamin D) to estimate vitamin D levels. We could establish a sufficiency range between 30 and 60 ng/ml measured in blood, with a recommended range for athletes of 40-50 ng/ml.

Where do we find it?

The main dietary sources of vitamin D are found in dairy products, oily or fatty fish and, to a lesser extent, in eggs. We also have enriched foods available, such as yoghurts or milk, which are interesting. Given its fat-soluble nature, it is advisable to take this into account to optimise vitamin D treatments and also its absorption, trying to ingest sufficient amounts of lipids in the diet and paying attention if they are reduced due to calorie restriction or nutritional preferences.

After all the tests we have seen, it is likely that many of us need a vitamin D supplement to reach an adequate status and benefit from this super vitamin.

How much vitamin D do we need?

The recommended daily intake of a vitamin D supplement is around 2,000 international units (IU) per day. Research conducted in northern Spain (reference) opens up the possibility of increasing this dose to 4,000 IU/day, accompanying the treatment for 8 to 12 weeks for subsequent blood testing.

It is important to take into account the diet and accompany the supplementation with meals with a certain amount of fatty acids (we could take advantage of the main meals of the day).

In addition to supplementation, everything in our power is recommended. As the main way of obtaining vitamin D is the sun, depending on our skin tone, the area where we live and our needs, daily exposure without sun cream during the time we spend outdoors may be enough, or we can try to take responsibility for spending more time in the sun and doing regular and gradual exposure and not binge on the sun in summer. We can also choose to do some WOD outdoors, take advantage of active rest days to expose ourselves or practice our mobility in the sun.

At SMART NUTRITION we can help you to optimise your vitamin D levels and make the most of its potential, as well as to build a solid nutritional base that covers all individual requirements and needs at any time of the season.

We provide a fully personalized service both in person and online. Please do not hesitate to contact us through our social networks or website.