Sun protection

UV rays work before the skin turns red

Ultraviolet is invisible. UVB plays a major role in sunburn, while UVA penetrates deeper into the skin and contributes to solar aging. This distinction remains a shortcut: both families can contribute to cellular damage and skin cancers. Not burning therefore does not mean that exposure has no effect.

Over the course of exposure, UV rays promote oxidative reactions and changes in the structures that support the skin. The complexion may become less uniform, spots more present and wrinkles more marked. Aging also depends on age, genetics and other factors: sun protection reduces a preventable part of this damage.

SPF measures protection, not authorized time

SPF compares the UV dose needed to cause redness with and without product, under standardized testing conditions. It mainly concerns protection against UVB.

The test uses an amount of two milligrams of product per square centimeter of skin. In practice, we often apply less and less regularly, which lowers the protection obtained. Dividing the amount does not simply calculate a new SPF. This is why a generous and even application is as important as the choice of the number printed on the tube.

Mineral does not mean mirror

Organic filters, which absorb UV rays, are often opposed to mineral filters, which reflect them like a mirror. This image is misleading: zinc oxide and titanium dioxide also protect mainly by absorbing ultraviolet rays. Reflection and dissemination exist, but do not alone explain their effectiveness; they also play a role in the white appearance that certain formulas leave on the skin.

Both families serve to limit the amount of UV rays that reach the skin. The result depends on the associated filters, their concentration and the complete formulation, not just the “mineral” or “organic” category. To choose, return to concrete criteria: UVA and UVB protection, tolerance, comfort and ease of applying a sufficient quantity. The product that is right for you is not necessarily the one that looks most natural.

Why tanning is not a substitute for protection

Melanin helps protect the skin, and naturally dark skin does not react to the sun quite like very light skin. This does not make UV harmless. Acquired tanning is a response to exposure and does not provide sufficient protection to continue without precaution. UV cabins are also not a protective preparation before the holidays.

A self-tanner can color the skin without a tanning session, but this coloring does not constitute sun protection, unless protection is explicitly indicated on a product and used according to its instructions. Supplements presented as a preparation for the sun do not replace clothing or cream. In the Australian skin aging trial, beta-carotene supplementation did not show an overall benefit on this criterion.

And vitamin D in all this?

UVB allows the skin to produce vitamin D, which explains the common question: would protection prevent you from getting enough? In practice, the synthesis varies depending on the season, latitude, age, pigmentation and lifestyle habits. Dietary intake and, when indicated, supplementation can also help meet needs without seeking harmful exposure.

It is therefore not necessary to schedule tanning sessions or get sunburned for vitamin D. If you have little exposure, have a risk factor for deficiency or are wondering about your intake, talk to a health professional. The answer can be adapted to your situation; it is not just a universal number of minutes in the sun without protection.