Vitamin D, sunscreens and summer: a guide to not missing and absorbing an essential vitamin

We live in a country with an average of 2,500 hours of sunshine per year, but it is very likely that you or someone close to you have recently been told that you are deficient in vitamin D. And it is that a large part of the Spanish population has low levels of this essential vitamin, especially if we compare them with those of citizens of northern European countries.

According to experts, there are several reasons, but if you want to achieve good levels of vitamin D this summer without putting yourself at risk from solar radiation, I invite you to continue reading.

Why is vitamin D important?

It is a vitamin that directly influences the health of our bones, so low levels can cause serious health problems.. Its main function is to strengthen our bone structure and regulate the concentration of minerals in them, so we can say that it is essential to have healthy and strong bones.

Which has benefits?

Having adequate levels of vitamin D in the blood is essential for the health of our bones, but it is not its only function, although it is the main one.

It also helps strengthen our defense system, the immune system, serves to regulate the levels of phosphorus and calcium within our body, essential for good muscle contraction and the propagation of nerve impulses, and contributes to good skin health.

What are the consequences of a lack of this vitamin?

Recommended blood levels of vitamin D for the average adult are between 20 and 50 nanograms per milliliter.

A lack of this vitamin can cause osteoporosis and our bones end up like Gruyère cheese, osteomalacia and our bone structures become soft and deformed, bone and back pain, fatigue, worse wound healing…. or even cavities.

Last year several investigations were even published that link its deficiency with dementia or chronic inflammation.

Do sunscreens prevent us from synthesizing vitamin D?

At the moment there is no very clear and generally valid answer.

It had always been believed by various epidemiological studies that sunscreen prevented the synthesis of vitamin D, but in 2019 a study was published in the British Journal of Dermatology that refuted this statement.. They concluded that it is possible to use sunscreen to prevent sunburn and skin cancer without affecting vitamin D synthesis.. The problem is that the group of people who were the object of the study were light-skinned (phototype 2-3) and these individuals produce vitamin D more easily, and the protection factor used was very low, specifically SPF 15.

We would need new studies to be carried out with people of different phototypes and more protective sun creams in order to have an answer that serves the population in a general way.

How can we sunbathe to get this vitamin?

Just fifteen minutes of exposure to the sun on the face and arms, about three times a week, are enough for our body to synthesize vitamin D.

But that ultraviolet radiation from the sun is dangerous for our skin, so to minimize the risks as much as possible, we will have to do this brief exposure to the sun in order to get the vitamin before eleven in the morning or after six in the evening.. At these hours the UV index is lower but sufficient. And simply with that little outing to run an errand in the street first thing in the morning will be enough to synthesize it.

If we are going to sunbathe or expose ourselves to it outside of those hours or for more than those fifteen minutes, we must never forget the sun protection cream.

What parts of the body absorb vitamin D best?

The face, arms and legs. Type B ultraviolet radiation from the sun is what allows us to transform the dehydrocholesterol in our skin into that vitamin D. Once synthesized, our body will store it in the liver and in fatty tissues to use it as needed.

Vitamin D and diet

It is estimated that around 85% of the synthesis of this vitamin will come from our exposure to the sun, but the remaining 15% comes from an adequate and varied diet.

Some of the foods that provide us with this vitamin D are eggs, fatty fish such as sardines, salmon or tuna, or fortified foods such as milk, cereals or yogurt.