What is vitamin D
Vitamin D is a fat-soluble vitamin. It is also known as the sunshine vitamin, as it is synthesized when the skin is exposed to sunlight. Vitamin D plays an important role in bone metabolism, muscle function and the immune system.
|Fat-soluble: something that is soluble in fats.|
Vitamin D and cholesterol
Yes, it's thanks to cholesterol and the sun that our body synthesizes vitamin D. More precisely, the sun's UV-B rays react with 7-dehydrocholesterol (a cholesterol derivative present in our bodies) to form vitamin D.
So it's good to remember the importance of cholesterol in our bodies, as it's one of the factors that enables us to synthesize vitamin D.
How does vitamin D work?
Vitamin D helps control the amount of calcium and phosphate you absorb from food.
Calcium is essential for healthy bones. Phosphate is needed for healthy bones, teeth, muscles, nerves and basic bodily functions.
Vitamin D comes in two forms:
- Vitamin D2 (ergocalciferol) is naturally present in certain plants.
- Vitamin D3 (cholecalciferol) occurs naturally in animals and is produced by the skin when exposed to sunlight.
The amount of time you need to spend in the sun depends on where you live, how much time you spend outdoors and the pigmentation of your skin.
You can cover your vitamin D needs with either form. But D3 is generally preferred, as it is better absorbed by the body, more effective and destroyed less rapidly than D2.
Vitamin D offers numerous health benefits.
Strengthens bones and musclesBones
Vitamin D ensures the proper absorption of calcium, an essential element for bones. In the presence of a vitamin D deficiency, the body cannot assimilate calcium from food and must take it from our bones.
This can lead to the following pathologies:
- Bone fragility
Calcium is an essential element for muscles. It helps muscle proteins to perform the work of contraction.
This means that vitamin D deficiency leads to calcium deficiency, and consequently to muscle loss.
In short, vitamin D is important for strong bones and muscles, increasing bone density and muscle mass.
Strengthens the immune system
Vitamin D boosts immunity and helps fight infection by regulating the activity of immune cells that trigger antiviral and antibacterial responses.
It activates and stimulates the innate and adaptive immune systems.
Innate immune system: Immediate defense, first barrier against infectious agents
Adaptive immune system: second barrier, the body recognizes infectious agents and acts accordingly.
Research has shown that it can help prevent:
- Acute respiratory infections
Vitamin D is active in the regulation of the well-being hormone serotonin.
That's why a course of D can reduce fatigue and anxiety.
Improves heart function
Vitamin D also plays a role in cardiovascular health. It keeps the heart and blood vessels in good working order. A deficiency could lead to..:
- Metabolic syndrome
And in return, an adequate level of vitamin D:
- Healthier blood vessels
- Stroke prevention
What are the best food sources?
Although produced by our bodies when our skin is exposed to the sun, we can find vitamin D3 in our diet.
Here is a non-exhaustive list of foods that can provide vitamin D3:
- Cod liver oil
- Fish such as herring, mackerel, sardines, salmon, trout and tuna
- Dark chocolate
- Whole milk
Is supplementation the solution?
Food supplements are the easiest way to get enough vitamin D3 every day. To avoid mistakes when choosing your supplements, we invite you to consult our article on "How to choose dietary supplements"..
Indeed, it can be difficult to get enough vitamin D3 from the sun alone, especially in winter.
Eating foods with a high dose of D3 can be difficult, so taking vitamin D3 in dietary supplement form can be beneficial.