Vitamin D supplements proven to help protect against flu – but do you still need them if you live in Spain?

By Lottie Verrier • Published: January 21, 2026 • 13:46 • 2 minutes read

Vitamin D vs. Flu: Shocking Study Results! Do YOU ...

Vitamin D lowdown Credit: Shutterstock / Anna Gawlik

New research out of the UK suggests that taking vitamin D supplements regularly throughout the winter months can help significantly reduce the risk of catching the flu or other respiratory nasties. This finding, while not exactly groundbreaking, has certainly re-ignited the conversation around the "sunshine vitamin," and it raises a really interesting question for those of us basking in the Spanish sunshine: does living in a sun-drenched country like Spain mean we can skip the supplements?

Vitamin D, as many of us know, is manufactured in the skin when it's exposed to UVB rays from sunlight. It’s absolutely crucial for all sorts of bodily functions, from regulating our immune systems to keeping our bones strong and our muscles working properly. Spain, with its famously sunny climate, *should* be a vitamin D production powerhouse, right? Well, not exactly. Surprisingly, numerous studies have consistently shown that vitamin D deficiency is actually quite common in southern Europe, including right here in Spain. I’ve seen it myself in friends and family!

Researchers are calling this the “vitamin D paradox”: plenty of sunshine, but surprisingly low average blood concentrations among the population. What gives?

The problem is multifaceted. For starters, modern life has us spending far less time outdoors than our ancestors did. Many of us work from home or in offices, often missing out on those crucial peak daylight hours. And when we *do* venture outside, we’re often slathered in sunscreen (which is important, don't get me wrong!) or covered up in long sleeves, all of which drastically reduces our skin's ability to produce vitamin D. It's a tricky balance to strike.

And let's not forget about winter. Even here in sunny Spain, the sun sits lower in the sky from late autumn to early spring, meaning those UVB rays are significantly weaker. Combine that with shorter days, cooler temperatures, and the tendency to wear more layers, and suddenly our vitamin D levels can plummet just as flu season kicks into high gear. It's a perfect storm, really.

Vitamin D isn't a direct flu-killer, of course. Instead, it plays a vital role in how our immune system responds to infection. Immune cells rely on adequate vitamin D to activate the necessary antimicrobial responses and keep inflammation under control.

Extensive reviews of various clinical trials suggest that taking regular, low-dose vitamin D supplements can indeed lower the risk of acute respiratory infections, especially in individuals who are starting out with low levels. It seems the benefits are greatest when supplements are taken consistently, rather than in large, infrequent doses. And again, during those darker, colder winter months, that extra boost becomes even more valuable. So, don't assume sunshine means sufficiency – get your levels checked!

Living in a sunny place definitely has its perks, but it doesn’t automatically guarantee you’re getting enough vitamin D. A simple blood test, recommended by many doctors, can tell you whether or not you need supplementation. If you *are* deficient, a modest daily supplement during the winter might be just what you need to support your immune health alongside other preventative measures like washing your hands regularly and getting enough sleep.

Euro Weekly News, known as the PEOPLE’S PAPER, is the leading English language newspaper in Spain. It's FREE and covers the Almeria, Axarquia, Costa Blanca North, Costa Blanca South, Costa del Sol, Costa Calida, Mallorca and beyond, supporting and inspiring the individual.