Vitamin D – A key nutrient for your health and sporting performance

Vitamin D: a pillar of bone health

Vitamin D, also known as the sunshine vitamin, belongs to the family of fat-soluble vitamins, meaning it dissolves in fats. This distinguishes it from water-soluble vitamins, such as group B or vitamin C, which dissolve in water.

Once produced or absorbed, vitamin D circulates in the blood, bound to a specific protein, Vitamin D Binding Protein (VDBP), which carries it first to the liver, then to the kidneys, where it is converted into its active form, 1,25-dihydroxyvitamin D.

Naturally synthesized by the skin under the action of UV-B rays, this vitamin plays a key role in bone health, as it promotes calcium absorption in the intestine and ensures good bone mineralization, thereby limiting the risk of premature osteoporosis or stress fractures.

So you see, if you want to act preventively against these risks, having a good vitamin D status is essential…. Much more so than trying to increase your calcium intake by eating large quantities of dairy products, as we all too often hear advertised! These products are certainly rich in calcium, but also in phosphorus, which upsets the balance between these two minerals and encourages calcium precipitation, disrupting its absorption.

Key player in muscle function and recovery

Researchers have discovered that our bodies have vitamin D receptors all over the place, including in our muscles. This means that this vitamin plays a direct role in their proper functioning.

When you’re training hard, or even when you’re injured, vitamin D becomes a real ally, helping your body to repair damaged muscle fibers by stimulating particular cells that can be thought of as “muscle stem cells”. Vitamin D also supports the work of the mitochondria, those little “power plants” that produce the energy your muscles need to recover and regain their strength.

Clearly, a good level of vitamin D is essential for good muscle recovery and for keeping muscles strong and resistant throughout training sessions.

Your immunity’s ally

Vitamin D also plays an essential role in protecting your body from infection. A veritable conductor of the immune system, it influences the activity of nearly 2,000 genes involved in cell growth, protein production and defense against pathogens.

In concrete terms, vitamin D acts as an immunomodulator : it stimulates key immune response cells, supports the production of natural anti-microbial molecules and promotes lymphocyte maturation. In short, it helps your body react better to microbes without triggering excessive inflammation.

Maintaining a good level of vitamin D gives your body the means to better defend itself, recover more quickly after intense effort and preserve your health throughout the sporting season.

How to optimize your rate in winter?

For your skin to produce vitamin D efficiently, it needs to be exposed to UVB rays of a specific wavelength, between 290 and 315 nanometers. These rays are most prevalent between April and September, when the sun is sufficiently “near”.

On the other hand, during autumn and winter, even when the sun is shining, it’s too low on the horizon to allow sufficient vitamin D production. And for those who say to themselves: “Yes, but I’ve had my fill this summer”, remember that vitamin D reserves are short-lived, covering only 2 to 3 weeks after the last effective exposure.

It’s also important to know that your ability to produce this vitamin depends on a number of factors: time spent in the sun, pollution levels, use of sunscreen, skin color and age. These parameters should always be taken into account when assessing your vitamin D status.

So, first of all, I’d advise you to have your vitamin D levels tested , so that you know your status and can then adjust your intake. Healthy standards are between 70-150 µg/L.

A daily intake at a physiological dose is more appropriate than a high consumption once a month in the form of ampoules. Choose lichen-derived vitamin D3 in drop form (or even microencapsulated).

In the event of a biologically-objectified deficiency, provide 75 IU/kg per day, without exceeding 5,000 IU per day (1 IU = 0.025 µg) for 3 months, then have the plasma dosage checked again, as it can vary considerably from one individual to another.

To supplement this intake, certain foods such assmall oily fish (sardines, herring and mackerel) are particularly rich in vitamin D. In addition to this vitamin, they also provide a significant quantity of omega-3, essential for your health.

Key points to remember

Much more than just a vitamin, vitamin D is a real pillar of your overall health and sporting performance. It supports your bones, strengthens your muscles, boosts your immunity and promotes recovery after exercise. Yet our modern lifestyles and lack of exposure to the sun mean that it is often overlooked as a nutrient.

Adopting the right reflexes, getting reasonable exposure to the sun in summer, monitoring your levels by taking a blood test in early autumn, and supplementing if necessary with food sources or suitable supplements, will help you maintain your health, energy, strength and good immunity over the long term.

In short, taking care of your vitamin D levels means investing in your health today and your performance tomorrow.