Does Sunscreen Block Vitamin D? Here’s What Science Says

We’ve all heard it: you need sunshine for vitamin D, but you also need sunscreen for protection. So what happens when these two essential health needs seem to clash? It’s a question that comes up time and time again, and honestly, it’s a valid concern.

Vitamin D is crucial for strong bones, a healthy immune system, and even your mood. But here’s the sunny truth: your SPF isn’t stealing your vitamin D.

At PoolBar, we’re all about that skin health, inside and out, so let’s break down what actually happens when you apply sunscreen and step into the sunshine.

Before getting into how sunscreen fits in, it helps to know how your body actually makes vitamin D. When sunlight hits your skin, UVB rays start a natural process that helps your body produce vitamin D3, the form your body can turn into usable vitamin D through the liver and kidneys.

UVB rays are the key players here. These are different from UVA rays, which go deeper into the skin and are linked to premature ageing and long-term damage.

Your body needs UVB exposure to kickstart vitamin D production, which is why sun exposure is considered a primary source of this essential nutrient. Learn more about the differences between UVA & UVA rays in our blog post.

How much vitamin D your body makes depends on several factors: how much skin is exposed, the time of day, the season, where you live, and your skin tone.

People with darker skin naturally have more melanin, which provides extra protection from the sun, but also means they may need a bit more sunlight to make the same amount of vitamin D as someone with lighter skin.

Now for the main event: does sunscreen actually block your body’s ability to make vitamin D? The answer is no, but it’s a bit more nuanced than that.

Under perfect, controlled conditions, sunscreen can block the UVB rays your body needs to produce vitamin D. These studies usually involve applying the exact recommended amount evenly, reapplying on schedule and using the sunscreen exactly as instructed.

In that scenario, yes, it can limit vitamin D production. That’s where the concern first came from and in theory, it is scientifically true.

Multiple studies examining actual sunscreen users have found that people who wear sunscreen daily maintain normal vitamin D levels. How is this possible?

SPF 50 sunscreen blocks approximately 98% of UVB rays, which means around 2% still reaches your skin. This tiny amount is perfectly safe and doesn’t compromise your protection, it’s actually enough to support vitamin D production.

Rest assured, your sunscreen is still doing its job, keeping your skin protected while letting your body maintain essential vitamin D levels. If you want to learn more about what SPF means and how it’s measured, read more in our blog post.

Application is imperfect. Research consistently shows that most people apply only 25-50% of the recommended amount of sunscreen. We also miss spots, apply it unevenly, and often forget to reapply every two hours. Follow our easy 4 step guide on how to apply mineral sunscreen for maximum protection here.

Some exposure happens anyway. Unless you’re applying sunscreen to every inch of exposed skin and reapplying religiously throughout the day, some UVB rays are getting through and providing Vitamin D.

Research published in the British Journal of Dermatology has found that even people who use sunscreen every day don’t have lower vitamin D levels than those who skip it. So while the lab theory makes sense, the real-world data says sunscreen isn’t stopping your vitamin D.

Many experts suggest that 10 to 15 minutes of sun exposure on your arms and legs, a few times per week, can help maintain vitamin D levels for people with lighter skin. Your morning coffee walk? It counts.

However, this varies based on individual factors. Someone with darker skin may need 30 minutes or more sun exposure to produce the same amount of vitamin D.

Your location matters too, if you live further from the equator, winter sunshine may not be strong enough, regardless of sunscreen use. Time of day plays a role as well, with midday sun being most effective for vitamin D production.

The key takeaway? A little sun goes a long way, and you should still wear sunscreen. Everyday activities like walking, commuting, or sitting by a window often give you enough exposure to keep your vitamin D topped up, without skipping protection.

You don’t have to rely on the sun alone for your vitamin D. Dietary sources like fatty fish (salmon, mackerel, and sardines) are naturally packed with it. Fortified foods like milk, orange juice, cereals, and plant-based milks, also help top up your levels.

Supplements are widely recommended by healthcare professionals, especially for people who live in areas with limited sunshine, work indoors, or have darker skin.

Vitamin D3 supplements are readily available and highly effective. Most adults need around 600-800 IU daily, though your doctor may recommend more based on your individual needs and blood test results.

This is why dermatologists and health organisations consistently recommend this approach: protect your skin from sun damage, and get your vitamin D from food and supplements. It’s a win-win that doesn’t require you to choose between skin cancer prevention and nutritional health.

If you’ve got a blood test coming up, it’s worth checking your vitamin D levels. Here’s a simple guide to what your numbers mean:

• Below 30 nmol/L = Deficient. Time to chat with your doctor about supplements.
• 30–50 nmol/L = On the low side. Your bones and overall health could use a little boost.
• 50+ nmol/L = Sweet spot. Your vitamin D is in a healthy range.
• 125+ nmol/L = Too much. More isn’t always better, and high levels could have side effects.

Here’s the bottom line: 1 in 5 people will get skin cancer by age 70, and up to 90% of cases are preventable with proper sun protection. That’s why wearing SPF every day isn’t optional, it’s essential.

Vitamin D deficiency can be addressed with diet and supplements, but skin damage and cancer from the sun are permanent. Every sunburn or unprotected day adds up over time. Ensure that you are using a broad spectrum sunscreen of at least SPF 30 or higher, to keep your skin protected.

Health authorities like the Skin Cancer Foundation all agree: the benefits of sunscreen far outweigh any small effect on vitamin D. No expert recommends skipping SPF to get your daily dose.

If you’re worried about your vitamin D levels, the safest move is a quick blood test and, if needed, supplements. That way, you’re protecting your skin and supporting your health.

So, does sunscreen block vitamin D? In a lab, yes, but in the real world, there’s no need to worry. You can wear SPF every day and still maintain healthy vitamin D levels through short bursts of sun, a vitamin-rich diet, and supplements if needed.

Sun protection isn’t about avoiding the sunshine, it’s about enjoying it safely. Whether you’re lounging by a pool in Palm Springs or strolling through London, your skin deserves reliable coverage.

That’s why PoolBar’s mineral sunscreens use zinc oxide for broad-spectrum protection, keeping your skin safe while letting you soak up life’s sunny moments.

Ready to protect your glow? Explore our PoolBar SPF collection and find your perfect sun care routine.