When you think of vitamin D, the first thing that comes to mind is probably sunshine. But are there also vitamin D foods we should be eating to boost our intake?

Since our bodies create vitamin D – responsible for keeping our bones, teeth and muscles healthy – from direct sunlight on our skin when we’re outdoors, this super-important vitamin has become associated with long summer days, exposed limbs and beach holidays.

While the NHS says that most people should be able to make all the vitamin D they need from sunlight during the spring and summer months in the UK (all importantly, even when wearing sunscreen), it’s another story once autumn and winter roll around.

This is where diet comes into play, and it becomes more about what you put into your body than onto it. From vitamin D-rich foods to powerful vitamin D supplements that optimise your intake, you can get your fix even in the darkest of months.

What is vitamin D, and why is it so important?

“Vitamin D is best known for supporting bone, muscle and immune health – and a big part of that is because it helps us to absorb and use calcium properly,” says Kirsten Humphreys, nutritional therapist at Bare Biology. “Research is also exploring links between vitamin D and other areas like mood, skin health and metabolic health. That science is still ongoing, but it highlights why vitamin D remains one of the most studied and most valuable nutrients there is.”

Because of modern lifestyles and the distinct lack of sunshine in the UK, vitamin D deficiency is relatively common – especially in autumn and winter. In fact, UK government data suggests around one in six adults and nearly 20% of children have low levels. And the impact can be huge.

“When Vitamin D is suboptimal, our whole system becomes more fragile,” says Rhian Stephenson, a nutritionist, naturopath, and the founder of supplements brand Artah. “You can see this in so many aspects of health, from mood and energy to more frequent infections and poor recovery. You can be doing everything right with diet, exercise and sleep, but if your Vitamin D levels are insufficient, it will be a struggle to feel your best.”

How much vitamin D should we be getting?

According to the NHS, everyone from the age of one year needs 10 micrograms (400 IU) of vitamin D a day, and a vitamin D level of 50 nmol/L is deemed “sufficient”. This includes pregnant and breastfeeding women, and people at risk of vitamin D deficiency. However, both Rhian and Kirsten are keen to stress that while public health recommendations are in place to prevent deficiency, higher levels could be beneficial to optimise vitamin D’s broader hormonal and immune actions.

“Some experts argue (and some research suggests) that higher levels, around 75 nmol/L and above, may provide additional support for areas such as immunity, bone strength, and muscle function,” Kirsten says. “But in nutritional therapy settings, we’re usually aiming for optimal health outcomes, not just ‘enough to avoid deficiency’.”

And if you’re already low in vitamin D, you might benefit from a higher dosage in order to catch up. “For this, it’s more common to see doses between 1000-4000IU, which is the safe upper limit,” adds Rhian.

Which foods are rich in vitamin D?

While vitamin C can be found in everything from oranges to potatoes, vitamin D is a little harder to come by in your everyday diet.

“There are almost no modern foods that are naturally dense in vitamin D, however, you can find it in oily fish and fish liver oils,” Rhian notes, although she adds that “farmed fish has lower vitamin D levels than wild fish.” Other sources that include vitamin D to a lesser extent include egg yolks and certain wild or UV‑exposed mushrooms, Rhian says.