We all probably know Vitamin D and that your skin produces Vitamin D when exposed to sunlight. It is often advised that (in spring and summer) we do not need Vitamin D in the form of supplementation, but is that really true?

Absorption of vitamin D

Let's look at how Vitamin D is absorbed. When the sun is shining outside and the sun strength is at least 4, the skin can absorb Vitamin D through the UV rays. It is important to go into the sun with bare arms, legs and face for at least 20 minutes without sunburn on your skin. Sunburn blocks the absorption of Vitamin D, so when you apply sunscreen you absorb little to no Vitamin D.

Most of the Dutch are at work a lot, don't get outside much, apply sunscreen when the first rays of sunlight arrive which makes the chance of getting Vitamin D deficiency very high.

In the fall and winter months, the sun power is below 4 which means you do not absorb Vitamin D, therefore, especially in the winter months, it is recommended to take Vitamin D in a supplement form.  

Vitamin D advice

Our advice is to take Vitamin D in supplement form all year round, provided you get outside in the summer months (July & August) with a minimum UV index of 4 without sunburn, are sure you are not Vitamin D deficient or if you go on vacation to a sunny country, otherwise there is a good chance that you will become deficient in the long run and may cause symptoms.

In fact, Vitamin D is involved in important processes such as:

1. Vitamin D contributes to normal blood calcium levels.
   2. Vitamin D contributes to the maintenance of normal bones.
   3. Vitamin D contributes to the normal absorption/use of calcium and phosphorus.
   4. Vitamin D plays a role in the cell division process.
   5. Vitamin D contributes to the normal function of the immune system.
   6. Vitamin D contributes to the maintenance of normal teeth.
   7. Vitamin D contributes to normal muscle function.
   8. Vitamin D is required for normal growth and development of children's bones.
   9. Vitamin D contributes to normal immune system function in children.

So what about nutrition?

Although vitamin D is primarily produced by exposure to sunlight, you can also find it in certain foods. Oily fish such as salmon, mackerel and tuna are excellent natural sources of vitamin D. Eggs, mushrooms and fortified dairy products also contain vitamin D.

In short, our advice is to eat foods rich in Vitamin D regularly, go outside for at least 20 minutes every day, and take Vitamin D in supplement form when this fails.