Is vitamin D good for the immune system?
You may have heard of vitamin D from various health campaigns and medical professionals, but do you know what it really does for you? Understanding this can help you to take better care of your body – and knowing what can impact the effectiveness of your immune system is just as important.
Keep reading to learn more about vitamin D and its role within the body.
What is vitamin D?
Vitamin D is one of several important nutrients that are needed within the human body. That’s why they’re called vitamins, because they’re vital to your health.[1]
This particular vitamin is predominantly generated in the body when we spend time in sunlight, though you can get some vitamin D from certain foods, such as oily fish, red meat, eggs and fortified breakfast cereals. Because of this link to the sun, you may be more at risk of a deficiency of vitamin D during the winter months when there are fewer hours of daylight and we tend to stay indoors for longer.[2]
Interestingly, we humans aren’t the only creatures to make and use vitamin D. Lots of animals and plants do as well – though their vitamin D can be slightly different from our own. Animals produce a form of vitamin D known as D3, which is the same kind we have. Plants, on the other hand, produce vitamin D2.[1]
Both of these kinds of vitamin D are available as supplements, and it’s not a bad thing to take a D2 supplement. However, vitamin D3 is typically more effective, and so may be preferable.[1]
What does vitamin D do?
Vitamins aren’t the only nutrients that help the body to run as it should, and sometimes these nutrients can have interlocking purposes. For example, calcium and phosphorus both have key roles to play in keeping the teeth, bones and muscles healthy. One role that vitamin D plays is to allow us to absorb and use these substances more efficiently, essentially boosting the positive effects they can have.[1,2]
There is also some research to suggest that low levels of vitamin D can make you more vulnerable to upper respiratory tract infections like the flu and the common cold. The study, which analysed data from over 19,000 people, found that a higher proportion of people with low levels of vitamin D had had a recent infection when compared to those with high vitamin D levels. In simpler terms, those who had low vitamin D levels were more likely to have suffered a recent upper respiratory tract infection.[3]
This is important because minor illnesses such as these can have a big impact on people’s lives even if the infection itself isn’t particularly dangerous. After all, nobody likes feeling ill. But this research suggests that having higher levels of vitamin D may reduce your risk of infection.[3]
Of course, this is only one study, and the medical community is far from certain about the effects vitamin D can have on the immune system. While standing outside in the sun can have its benefits,[4] there’s no guarantee it will stave off a cold if you feel a sore throat coming on.
So what should you do if you start to feel the symptoms of a sore throat? Well, you can treat a sore throat at home with Chloralieve honey and lemon throat lozenges, which contain an anaesthetic to numb pain and two antiseptic compounds to help fight off the infection. If you don’t feel better after a couple of days or you have any other concerns, speak to your GP.[5]
If you don’t have an upper respiratory tract illness or you just want to know what you should do about your vitamin D levels in general, then the advice is simple. It’s recommended that most people should take a vitamin D supplement from October through to April, since it’s harder to get enough vitamin D naturally during the colder months.[2]
You can also speak to a healthcare provider to learn whether you’re likely to be at a greater risk for vitamin D deficiency. This can happen if you stay indoors a lot, you mostly wear clothes that cover all your skin when outdoors or if you have dark skin. Fortunately, supplements are available to help you keep your vitamin D intake at the appropriate level all year round.[2]
Resources:
[1] – https://www.cuimc.columbia.edu/news/whats-deal-vitamin-d
[2] – https://www.nhs.uk/conditions/vitamins-and-minerals/vitamin-d/
[3] – https://www.nih.gov/news-events/nih-research-matters/low-vitamin-d-levels-associated-colds-flu
[4] – Mead, M Nathaniel. “Benefits of sunlight: a bright spot for human health.” Environmental health perspectives vol. 116,4 (2008): A160-7. doi:10.1289/ehp.116-a160 Available at: https://pmc.ncbi.nlm.nih.gov/articles/PMC2290997/
