A balanced diet is essential for everyone anyway, but as we career head first into autumn and winter with a global pandemic still on our hands, it’s more important than ever that we stay as healthy as possible in order to support our immune systems.
Whether there is a direct link between outcomes of Covid-19 and vitamin D status is yet to be scientifically verified, but what we do know is that reports say 1 in 5 of us in the UK are deficient in the vital nutrient and when it comes to our immune systems, vitamin D is our best friend. Dr Selena Langdon tells us that ‘one of vitamin D’s most important roles is keeping your immune system strong, so you’re able to fight the viruses and bacteria that cause illnesses.’
Additionally, ‘a number of studies have found that taking vitamin D supplements at a dosage of up to 4000 IU daily may reduce your risk of respiratory tract infections.’ In other words, doing everything you can to help support your health during the pandemic is never going to be a bad thing.
So how much vitamin D do we need and how do we get it?
According to NICE guidelines, the basic minimum requirement for those aged 4 and over is 400 IU of vitamin D per day all year round. ‘However, this is such a small amount,’ says Dr Langdon. ‘A more beneficial dose is 4000 IU.’ There are two ways to get vitamin D in you: sunlight and diet.
Vitamin D from sunlight
It’s fairly commonly known that the most effective way to get our vit D topped up is through our skin soaking it up via the sun’s UVB rays, which is why many of us end up with a deficiency during the winter. Dr Langdon says that the body can still make vitamin D when outside on a cloudy day, but it will take longer to produce a reduced amount, making it a less effective solution for vitamin D production during the autumn and winter.
Vitamin D from food
Therefore, during the winter, it’s a good idea to try to incorporate as many foods that contain high levels of vitamin D as possible. These include oily fish, fish liver oil, eggs, pork chops, fortified foods such as milk, soya, tofu, cereals and orange juice and some mushrooms.
The top five oily fish with the highest levels (based on the usual serving size) are: salmon fillet, smoked white fish, swordfish fillet, rainbow trout fillet and canned sardines.
The varieties of mushrooms that are the richest sources of vitamin D include chestnut, portobello, white button, shiitake, chanterelle and morel. Interestingly, although mushrooms contain the weaker version of vitamin D (D2 as opposed to D3, which is almost twice as powerful), the reason they contain it at all is because, like our own skin, they absorb it from sunlight. This means that if you leave mushrooms on a sunny windowsill for about 20 minutes prior to cooking, their vitamin D content will increase further, according to nutritionist Lily Soutter.
However, it’s worth noting that to get Dr Langdon’s recommended 4000 IU a day, you’ll be hard pushed to reach that through food alone. For example, one large scrambled egg would provide approximately 44IU per serving, she explains. That’s a lot of eggs to eat to reach 4000 IU.
This is where a supplement comes into its own, as you know exactly how much vitamin D you’re getting, making any sunlight or enriched foods you consume an added bonus. These can be found at any pharmacy or health food shop, such as Holland & Barrett.