Most of us are familiar with the well-established benefits of vitamin D. If you’re not, you may want to brush up on them by reading our previous article on the sunshine vitamin. Now, let’s proceed to learning the secret relationship between vitamin D, the immune system, and allergies in adults and children.
Does vitamin D have anything to do with your immune system?
Yes. Vitamin D is a well-known immunomodulator. An immunomodulator is a substance that regulates your immune response to something which can cause an allergic reaction (like dust or pollen). It normalises your response for optimal functioning. It is quite amazing.
For vitamin D and its active metabolites to exert its effects, there has to be a receptor for it. The vitamin D receptor is the one who acknowledges the presence of vitamin D in your body, meets with it and welcomes it into your system. These receptors aren’t just located in your skin, bones, and gut. Guess what? They’re also located in your immune cells.
Whenever there’s a meet and greet between vitamin D and its receptors on your immune cells, partying (activation) happens. When the partying starts, your immune cells are able to function at their very best. We’re not just referring to one type of immune cell here. It’s really a family affair because lymphocytes, macrophages, dendritic cells, and others are all invited to the party.
Vitamin D Deficiency May Lead to More Allergies in Children
Numerous research studies have pointed out that children from industrialised countries like New Zealand, Australia, the Republic of Ireland, and the United Kingdom develop more allergies than non-industrialised nations. They also found that children from Westernised countries spend approximately 90% of their time indoors (significantly less sunlight). Five percent of adults in New Zealand have vitamin D deficiency, with a further 27% below the reference range. Australian adults have a similar situation with more than 30% of them low in vitamin D. If vitamin D intake isn’t topped up with supplementation, it could lead to serious health consequences. The researchers have hypothesised that there may be an important link between vitamin D deficiency and the development of childhood allergies. Interesting, huh?
Let’s get back to the partying (activation) of immune cells and vitamin D. Sometimes, we can’t avoid the arrival of a gate crasher. The gate crasher can be viewed as a foreign substance which can elicit an allergic reaction. Immune cells present at the party who have been activated by vitamin D can confront or kick out this gate crasher (who wasn’t invited). But imagine what could happen if your child doesn’t have enough vitamin D-activated and responsible immune cells to kick out this gate crasher? This is what happens when your child has a vitamin D deficiency. Not enough responsible immune cells attend the party. The end result? More gate crashers and allergies. Vitamin D deficiency leads to a poor immune response to allergies. Your child’s immune system sends the wrong type of immune cells and perpetuates the allergic response.
Can vitamin D supplementation during pregnancy prevent the development of allergies in children?
Pregnant mums may want to increase their vitamin D supplementation to decrease the incidence of childhood asthma and allergies when their babies are born. A mother with an optimally functioning immune system will give her unborn baby lots of immunoglobulins (preformed antibodies to respond well to those gate crashing foreign substances). This can help modulate her baby’s allergic response when he or she grows up.
What about adults with established allergies?
Adults with established allergies can also benefit from vitamin D supplementation. Studies have shown that vitamin D may decrease the frequency and severity of allergic symptoms among adults with known allergies. Not only that, but vitamin D plays an important part in maintaining a healthy balance of Th1 and Th2 immune cells which need to be in the right balance to prevent allergic reactions.
Other Uses of Vitamin D
Vitamin D supplementation can also enhance immune defenses against skin infections. People who have vitamin D deficiency, have fewer activated proteins on the surface of their skin to fight bacteria and viruses. These proteins are collectively called antimicrobial peptides. The best of these antimicrobial peptides is cathelicidin. You see, cathelicidin and vitamin D share a special bond. Cathelicidin needs vitamin D to regulate it so it can get rid of bacteria and viruses from your skin.
Also, supplementing with vitamin D showed great promise in decreasing the severity of symptoms in asthma, atopic dermatitis, and other skin infections.
Vitamin D may even alter intestinal flora helping to prevent issues with intestinal permeability. Which in turn could prevent food sensitivities. Another area correlated with vitamin D levels, is lung function. Vitamin D deficiency appears to be a contributor to poor lung function.
While the connection between the health of your immune system and your vitamin D levels is still being investigated, it’s clear that they work hand in hand and need each other. So just make sure you’re getting plenty of the sunshine vitamin, regardless of whether you’re pregnant, a child or a full grown adult.