As the colder and less sunny seasons approach, the issue of vitamin D often comes to the fore. And with good reason: this vitamin, often called the ‘sunshine vitamin’, plays an essential role in maintaining our overall vitality. Far beyond simply promoting bone health, it contributes to the balance of our immune system, our mood, our energy levels, and also many more subtle metabolic functions.
However, despite its importance, a large part of the population is deficient in vitamin D, sometimes without even knowing it.
In this article, I invite you to discover why vitamin D is so valuable, the reasons why we are often deficient in it, and how to support it naturally on a daily basis.
What role does vitamin D play in the body?
Vitamin D acts as a conductor in our body. It is involved in many physiological processes that are essential to the body’s overall balance.
Bone and mineral health
Vitamin D facilitates the absorption of calcium and phosphorus in the intestines, allowing them to be properly absorbed into the bones and teeth. This role as a mineral mediator is essential for maintaining strong bone structure and preventing demineralisation. Even a moderate deficiency can weaken bone mass and promote disorders such as osteopenia or osteoporosis.
Immune system support
It also plays a role in modulating the immune response. By activating certain defence cells, vitamin D helps the body to respond better to infectious agents and regulate inflammatory processes. An adequate intake therefore contributes to improved resistance, particularly during periods of reduced sunlight when the natural defences are often under greater strain.
Emotional balance and vitality
Vitamin D also contributes to emotional stability and overall energy levels. It influences the synthesis of certain neurotransmitters involved in mood regulation, such as serotonin. Insufficient levels can therefore lead to low mood, lack of energy or sleep disorders, particularly during the winter months.
Metabolic and hormonal functions
Finally, vitamin D acts on several metabolic pathways: it is involved in hormone regulation, muscle function, cardiovascular health and glucose metabolism. These multiple interactions explain why it contributes to the harmonious functioning of the body as a whole.
Why our vitamin D requirements are often poorly met?
Despite its importance, a large proportion of the population has vitamin D levels below the recommended levels. Several factors related to our lifestyle and individual characteristics explain this now very common situation.
Modern lifestyle
Our current habits considerably limit our natural exposure to the sun, the main source of vitamin D synthesis. Between indoor work, transport, sedentary leisure activities and prolonged use of screens, our skin is rarely exposed to direct sunlight for long enough.
The influence of the seasons and latitude
Skin production depends heavily on the time of year and geographical location. In certain latitudes, between October and March, the sun’s rays are too low to allow for effective synthesis. The further away from the equator, the longer this ‘solar break’ period lasts, which explains the frequent drop in vitamin D levels at the end of winter.
Individual characteristics
Certain profiles have increased needs or lower synthesis:
- elderly people, whose skin produces less vitamin D;
- pregnant or breastfeeding women, whose needs increase;
- people with dark skin, as melanin acts as a natural UV filter;
- those suffering from digestive disorders (malabsorption, coeliac disease, Crohn’s disease, etc.);
- overweight or diabetic individuals, as vitamin D is fat-soluble and can be “stored” in fatty tissue;
- individuals with kidney weakness, limiting the conversion of vitamin D into its active form.
Why our vitamin D requirements are often poorly met?
Maintaining healthy vitamin D levels depends on several simple and complementary factors.
Get reasonable exposure to the sun
The main source of vitamin D is still skin synthesis under the effect of UVB rays. Exposure of 15 to 30 minutes per day, with your arms and face uncovered, is often sufficient in spring and summer. Ideally, you should aim for the sunniest hours of the day (between 11 a.m. and 3 p.m.), while avoiding prolonged exposure, which can damage the skin.
Focus on a suitable diet
In terms of food, natural sources of vitamin D are relatively rare. However, it remains a valuable source of support.
It is found in oily fish (salmon, mackerel, sardines, herring), cod liver, egg yolks, certain mushrooms and fortified products. Combining these foods with sources of good fats (olive oil, nuts, avocado) promotes better absorption.
Consider targeted supplementation
When sun exposure and diet are no longer sufficient, supplementation may be recommended, particularly in autumn and winter or depending on the results of a blood test.
It is recommended to choose vitamin D3, which is more bioavailable than D2, ideally from a natural source (plant-based or derived from lanolin). To optimise its absorption, co-supplementation with magnesium and vitamin K2 is particularly beneficial: magnesium promotes the active conversion of vitamin D, while K2 directs calcium to the bones rather than soft tissues.
Finally, regular blood tests allow the dose to be adjusted according to individual needs, as excessive supplementation is also undesirable.
Vitamin D therefore plays an essential role in the overall balance of our body.
So why not start today by assessing your intake, adjusting your routine and making this vitamin a real ally for your everyday health?