Vitamin D isn’t usually the first vitamin we think of when we think of our immune health. It’s usually vitamin C, which is found in citrus fruits, berries and kiwi fruits. Vitamin C is crucial for a healthy immune system, but it’s not the only vitamin that supports our immunity.
Vitamin D is also crucial for good immune health. We normally think of the benefits of vitamin D to our teeth and bones, and we’d be right for thinking that, but the immune system also relies on vitamin D to help defend us against illness and disease.
How vitamin D supports a healthy immune system
The immune system is a complex system of cells, molecules, tissue and organs, all with an essential role. It helps to defend us against disease with a smart two pronged attack – a system of ‘seek and destroy’ which seeks out invading pathogens in order to destroy them (carried out by a branch of the immune system called the innate immune system) and a memory bank (carried out by the adaptive immune system) that helps to remember pathogens so that we’re fully equipped to fight them should we come across them again.
Vitamin D helps to modulate our immune response by playing a role in the switching on and off of some of the cells of the immune system called the B cells and the T cells. In doing so, during an immune response, these cells are able to both deal with the threat, and communicate to other cells and molecules that there’s a threat to conquer.
Where do we get our vitamin D from?
We can see that without enough vitamin D, we run the risk of developing an impaired immune system. So, we just eat enough vitamin D rich foods, right?
Not quite.
Unlike all other vitamins, we don’t get much of our daily recommended amount of vitamin D from food. Vitamin D fortified dairy products and cereals, egg yolks, mushrooms (to a certain extent) and fish with edible bones (such as pilchards and whitebait) are good sources of vitamin D, but we’d have to eat an awful lot of these foods to get enough.
Instead, the body manufactures vitamin D after sunlight hits the skin. That’s why it’s commonly called the sunshine vitamin. During the summer, when sunlight levels are high and we cover up less of our skin, we’re generally thought to get enough vitamin D.
But during the colder, darker months from October to March, we’re all thought to be at risk of a vitamin D deficiency. That’s why it’s recommended that those of us living in the Northern hemisphere take a 10mcg daily supplement of vitamin D to make sure we’re not deficient.
Vitamin D and mental health
Vitamin D also plays a role in supporting our mental health too. It’s now thought that Seasonal Affective Disorder, or SAD is linked to low levels of vitamin D, not just low levels of mood boosting sunlight. SAD leads to a low mood, lethargy, poor concentration and other poor mental health symptoms and is often referred to as winter depression.
Feeling stressed and anxious can mean that the immune system becomes compromised, so it’s important to take your vitamin D supplement in the autumn and winter months.
The NHS are now advising that we continue to take 10mcg of vitamin D daily at the moment, since due to the coronavirus pandemic, we’re all staying inside for much longer, so make sure you’re topping up your levels of this immune supporting essential nutrient.
