Sunscreen and Vitamin D - What the Headlines Missed

You may have seen headlines claiming that daily sunscreen use causes Vitamin D deficiency.
It is a topic that sparks debate every summer, but as is often the case, the truth is more nuanced.

Here is what the science really says.

The headlines got it half right

Yes, sunscreen can influence Vitamin D production - but the story doesn’t stop there.
A new Australian study by Giblin et al recently explored this question, and while it was well designed, context matters.

A well-run study - but context matters

First, credit where it’s due: this was a strong study, and the researchers deserve recognition for tackling an important public health question.

The trial included participants from across Australia’s east coast - from sunny Townsville to cooler Hobart. Almost half lived in lower-UV regions like Melbourne and Hobart, and about two-thirds were women. Around ten percent said they never burn, likely reflecting darker skin tones more prone to Vitamin D deficiency.

That diversity matters. It means the study paints a broad picture of the population - but not necessarily of you.

We all have unique combinations of skin type, lifestyle, genetics, and sun exposure. So while the study offers useful data for national guidelines, it doesn’t predict how daily sunscreen use will affect your individual Vitamin D levels.

What the study actually found

The trial followed roughly 600 people. Half were asked to apply sunscreen every day; the rest continued their usual habits. Researchers measured everyone’s Vitamin D levels before and after summer, and again the following winter.

By the end of the study, the sunscreen group had only a 17% higher rate of Vitamin D deficiency. Importantly, about one-third of participants were already deficient before the study even began - meaning most of the difference came from people who started at a lower baseline, not because of sunscreen use itself.

So, what does this mean for you?

Vitamin D levels are shaped by many factors - where you live, how much time you spend outdoors, your skin tone, and even genetics. It’s rarely a one-size-fits-all story.

Population-level research helps guide public health advice, but it doesn’t always mirror the needs of the individual. What’s true on average might not apply to you. That’s why good medicine always looks at the person - not just the data.

Don’t ditch your sunscreen

Here’s the takeaway the headlines missed:
Even the study’s authors cautioned that their findings should not be used as a reason to stop wearing sunscreen.

Sunscreen remains one of the most effective defences against UV-related skin damage and visible ageing - not to mention serious conditions like melanoma. A small, seasonal variation in Vitamin D is manageable; unprotected UV exposure is not.

At Actaskin, we believe in balance. Protect your skin daily. Get a little safe sun exposure when you can. And if you’re concerned, ask your GP for a simple Vitamin D test - it’s quick, inexpensive, and provides peace of mind.

Reference

Giblin, L. et al. Effect of Daily Sunscreen Use on Vitamin D Concentrations: A Randomized Clinical Trial.
JAMA Dermatology, 2025.