Preparing Your Skin for the Sun: Nutrition, Hydration and Protection

📌 This article is Part 2 of our series on the sun. Part 1 is here: What the Sun Really Does to Your Body →

Sun protection is often reduced to a single gesture: sunscreen. But the way the skin responds to the sun does not depend only on what we apply on top of it.

It also depends on its internal state: its lipid barrier, hydration level, antioxidant reserves, nutritional status and repair capacity.

Preparing the skin for the sun does not mean making it "invincible" against UV rays. No diet, supplement or antioxidant replaces seeking shade, wearing protective clothing or using appropriate sun protection when necessary.

But skin that is better nourished, better hydrated and better supported is better able to manage part of the oxidative stress generated by exposure.

The skin also prepares from the inside

The skin is a living organ, constantly renewing itself. It contains lipids, proteins, water, pigments, antioxidant enzymes, immune cells and repair systems.

When it is exposed to UV rays, it does not remain passive. It produces melanin, activates defense mechanisms, mobilizes antioxidants, triggers inflammatory signals and repairs part of the cellular damage.

But these mechanisms require resources.

A diet low in protein, essential fatty acids or micronutrients can weaken the skin's response. Conversely, a diet rich in polyphenols, healthy fats, protein and minerals better supports the terrain.

It is a complementary lever.

Carotenoids: supporting the skin's antioxidant defense

Carotenoids are natural pigments found in many colorful fruits and vegetables. They gradually accumulate in the skin and contribute to its antioxidant defense.

They do not block UV rays, but they help neutralize part of the free radicals produced after exposure.

Lycopene is one of the most studied carotenoids for the skin. It is mainly found in red and orange foods such as tomatoes, watermelon, red bell pepper and pink grapefruit. Its absorption depends greatly on the food matrix: it is generally better absorbed when consumed in a meal containing fat, and certain processed or heated forms may be more bioavailable than the raw food alone.
Beta-carotene is found in carrots, sweet potatoes, squash, apricots, mangoes, melon, spinach and other leafy greens. It contributes to the skin's antioxidant defense and may help support a more golden complexion.
Lutein and zeaxanthin are known for their role in the retina, but they are also present in the skin. They are found in spinach, kale, Swiss chard, broccoli, eggs and leafy greens.
Astaxanthin, a red-orange pigment produced by certain microalgae and found in wild salmon, trout, krill and some shellfish, is also studied for the skin. Data suggest potential interest for oxidative stress, elasticity and certain markers related to photoaging.

Supplementation, however, requires more caution: high-dose beta-carotene is not recommended for smokers, former heavy smokers or people exposed to asbestos.

The goal is to regularly increase, through food, the plant pigments that support the skin's antioxidant capacity.

Polyphenols: strengthening the response to oxidative stress

Polyphenols are plant compounds found in green tea, berries, grapes, citrus fruits, cacao, coffee, aromatic herbs, spices and extra-virgin olive oil.

They have well-documented antioxidant and anti-inflammatory effects. Some studies suggest they may help support the skin's resistance to UV-induced stress, especially when consumed regularly.

Fatty acids: supporting the skin barrier

The skin is not only a surface. It is also a barrier.

This barrier depends partly on the quality of the lipids that make up cell membranes and the skin's hydrolipidic film.

Omega-3s, found in sardines, mackerel, anchovies, herring, wild salmon, walnuts, chia seeds and flaxseeds, contribute to inflammatory balance and membrane quality.

They may help support the quality of the skin barrier, hydration and recovery, especially in people with dry, inflammatory or reactive skin.

Conversely, a diet very low in healthy fats can make the skin more fragile: tightness, dryness, sensitivity, slower recovery.

Hydration: a basic but often underestimated factor

Hydration is often treated as generic advice. And yet, in summer, it becomes central.

Heat, sweating, sea salt, chlorine, alcohol and long days outdoors increase water and mineral losses. Dehydrated skin is more fragile, more uncomfortable, more reactive and recovers less well.

Hydration is not only about water. It also depends on:

sodium, potassium and magnesium intake;
consumption of water-rich fruits and vegetables;
alcohol intake;
sweating;
physical activity;
sleep.

In summer, athletes, children, older adults, pregnant women and people who sweat a lot need to pay particular attention to hydration.

Skin that feels hot, tight, stings, becomes uncomfortable or marks more easily does not only need cream. It often needs to be hydrated from the inside.

Protein: giving the skin the materials it needs to repair

We talk much less about the role of protein when we talk about sun exposure. And yet, the skin is a constantly renewing tissue. It needs amino acids to produce collagen, elastin, keratin, enzymes, transporters and repair proteins.

A diet too low in protein can weaken the quality of the skin, hair and nails, especially during periods of stress, training, calorie deficit or insufficient recovery.

The aim is:

enough protein at each meal;
enough vitamin C for collagen synthesis;
enough zinc, copper and iron if deficient;
enough total energy.

Skin that needs to repair requires building materials.

Supplements: useful only when the terrain justifies them

Supplements can be useful in certain contexts, but they should not become a false sense of security.

What may make sense depending on the terrain:

Beta-carotene may be interesting as a short-term course before a period of high exposure, especially if the diet is low in colorful fruits and vegetables. But it is not suitable for everyone, especially smokers and former heavy smokers.

Vitamin D remains highly individual. In summer, it may become less necessary for someone who is regularly exposed to the sun, but it remains relevant in cases of darker skin, low exposure, northern latitude, older age, obesity or documented deficiency.

Zinc may be useful in cases of deficiency, inflammatory skin, acne, slow wound healing, fragile immunity or insufficient dietary intake. But prolonged zinc supplementation can disrupt copper balance. It should therefore be targeted.

Polypodium leucotomos is a plant extract studied in oral photoprotection. Some data suggest potential interest as a complementary support, particularly for the inflammatory response to UV rays or certain pigmentary terrains. The study data remain preliminary.

The real question is not: which supplement should I take before going into the sun? The real question is: what terrain needs support?

Sunscreen: choosing protection properly

Sunscreen is a protective tool. It reduces UV exposure, especially when it is well chosen, applied in sufficient quantity and reapplied properly.

But it should not be thought of as perfect armor.

First, SPF mainly concerns protection against UVB rays, and therefore the risk of sunburn. To also protect against UVA rays, you need to choose a broad-spectrum sunscreen.

Then, effectiveness depends heavily on real-life use. Many people do not apply enough, forget certain areas, do not reapply after swimming or sweating, or believe that a high SPF allows them to stay much longer in the sun. That is not the case.

For prolonged exposure, you need to combine:

shade;
clothing;
hat;
sunglasses;
hydration;
broad-spectrum SPF 30 minimum sunscreen;
reapplication every two hours, and after swimming or sweating.

SPF, UVA, UVB: what the label really means

A good product should protect against UVB rays, which are largely responsible for sunburn, but also against UVA rays, which are more involved in oxidative stress, skin aging, pigmentation spots and deeper damage.

That is why you should choose broad-spectrum protection, ideally SPF 30 minimum when exposure is prolonged, repeated, or happens during the strongest hours.

SPF, or Sun Protection Factor, indicates the level of protection against UVB rays, the rays most involved in sunburn. It measures the ability of a sunscreen to delay the onset of a burn compared with unprotected skin. SPF 30 filters about 97% of UVB rays, compared with about 98% for SPF 50, when properly applied. To also limit the impact of UVA rays, which are more involved in skin aging, pigmentation spots and deeper damage, you need to choose broad-spectrum UVA + UVB protection.

Sunscreen filters: which ones to prioritize?

There are two main families of sunscreen filters:

Mineral filters, mainly zinc oxide and titanium dioxide, act mostly on the skin's surface by scattering, reflecting and absorbing part of UV radiation. They are generally better tolerated by sensitive skin and are the preferred option for people who want to limit exposure to controversial organic filters.
Organic filters, often called "chemical" filters, absorb UV rays and convert them into less harmful energy. They often have a lighter, more transparent texture.

The issue is that some of these filters do not remain only on the surface of the skin.

Several studies have shown that some organic filters can enter the bloodstream after repeated application. This does not mean that all chemical sunscreens are "toxic." But it does mean we cannot dismiss the question either, especially when safer and better-tolerated alternatives exist.

Some filters raise more questions, particularly because of their absorption, potential endocrine effects, persistence in the environment or impact on aquatic ecosystems. The ingredients to watch or limit, especially for children, during pregnancy, on hormonally sensitive terrain or reactive skin:

| Watch / limit | Why? | | --- | --- | | Oxybenzone / benzophenone-3 | Controversial filter due to its potential endocrine effects and environmental impact. | | Octinoxate / ethylhexyl methoxycinnamate | Filter discussed for its potential endocrine effects and impact on aquatic ecosystems. | | Homosalate | Filter reassessed for safety questions and potential endocrine disruption. | | Octocrylene | May raise concerns in reactive skin; also discussed for environmental impact and certain by-products. Degradation into benzophenone, a substance classified as possibly carcinogenic, can occur over time, especially after prolonged opening. So be careful with old sunscreen tubes containing it. | | 4-methylbenzylidene camphor | Controversial filter, particularly for its potential endocrine effects when present. | | Parfum / fragrance | Fragrance is often underestimated. In summer, the skin is already exposed to heat, UV rays, salt, chlorine and sweat; fragrance can increase the risk of irritation, skin reactions or photosensitivity. | | Sprays and powders | Coverage is often less even; inhalation risk, especially near the face. |

In practice, the best reflex is to look for a sunscreen with:

| Prioritize | Why? | | --- | --- | | Broad-spectrum UVA + UVB | To cover both UVB rays, responsible for sunburn, and UVA rays, more involved in skin aging, pigmentation spots and deeper damage. | | SPF 30 minimum | Sufficient in most situations if the sunscreen is properly applied and reapplied. | | Mineral filters | Often better tolerated, especially for sensitive skin, children, pregnancy or reactive terrains. | | Zinc oxide | A mineral filter of interest for broader protection, especially against UVA rays. However, nanoparticle formulations present safety questions distinct from larger-particle formulations. Nanoparticles may be more likely to cross the skin barrier and may therefore present more potential concern. | | Fragrance-free | Lower risk of irritation or reaction on already exposed skin. | | Cream, lotion or stick | More precise and more even application than a spray or powder. |

If you only have a conventional sunscreen on hand and you are in full sun, use it. Sunburn is an immediate and well-documented risk.

But if you are buying a product, you might as well choose a cleaner, simpler, fragrance-free formula with better-tolerated filters and real UVA/UVB protection.

Finally, no sunscreen should make you feel like you can stay in the sun indefinitely. Even with a good SPF, exposure still needs to be adapted. The most reliable protection remains a combination of shade, hat, sunglasses, clothing, hydration and sunscreen when exposure is prolonged or repeated.

Sunscreen is not permission for overexposure. It is one layer of protection among others.

Protecting hair and nails too

Summer does not only stress the skin. The sun, salt, chlorine, heat and repeated washing also weaken hair and nails.

Hair can become drier, more brittle and duller. The scalp can also burn, especially along the part, on fine hair or thinning areas.

The basics are simple:

protect the scalp with a hat;
rinse hair after the sea or pool;
avoid harsh washing;
maintain sufficient intake of protein, zinc, iron, omega-3s and vitamin D if deficient.

Hair loss, significant breakage or brittle nails often require looking deeper: iron, thyroid, hormones, inflammation, stress, sleep and energy intake.

Biomarkers: what to look at?

Certain markers can be useful when the terrain justifies it: persistent fatigue, fragile immunity, inflammatory skin, hair loss, brittle nails, history of deficiency, low sun exposure, digestive issues, pregnancy, perimenopause, intense training or current supplementation.

The first marker to look at remains 25-OH vitamin D. It is the reference marker for assessing vitamin D status, whether it comes from the sun, food or supplementation.

Ferritin may be relevant in cases of fatigue, hair loss, heavy periods, intense training or a diet low in iron. It is an important terrain marker for energy, recovery, skin, hair and nails.

Zinc can be interesting in cases of inflammatory skin, acne, slow wound healing, fragile immunity, hair or brittle nails. It should not be supplemented blindly over the long term, because excess zinc can disrupt copper balance.

Biotin (vitamin B8): deficiency is rare, but it is involved in hair loss and brittle nails.

The omega-3 index, or more broadly an erythrocyte fatty acid profile, can be useful for assessing EPA/DHA status and omega-3/omega-6 balance. It provides information on an important aspect of the terrain: cell membrane quality and inflammatory balance. The omega-6/omega-3 ratio can provide a general indication, but it should be interpreted with caution. When available, the omega-3 index or the AA/EPA ratio are often more informative.

hs-CRP can provide an indication of systemic inflammation; it can help identify whether the terrain is inflammatory.

To finish

Preparing your skin for the sun also starts from the inside: with a diet sufficiently rich in plant pigments, polyphenols, healthy fats, protein, water and minerals.

But this never replaces appropriate external protection when exposure is prolonged, repeated, or occurs in a more intense context: shade, clothing, hat, sunglasses and broad-spectrum sunscreen if needed.

The goal is not to hide from the sun or to expose yourself without limits. The goal is to strengthen the terrain, choose exposures more intelligently, and enjoy the sun without paying an unnecessary cost.

The information in this article is provided for educational purposes only and does not constitute medical advice. It does not replace consultation with a qualified healthcare professional. Consult your doctor before making any significant changes to your supplementation, especially in cases of pregnancy, medical treatment, chronic disease, history of cancer, current or past smoking, or before interpreting biological results.

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