Does vitamin D help the immune system?  Yes it does and in this article we will look at some of the research papers on Vitamin D and its role in helping prevent against infections.  We will also look at how it helps your overall immune health. 

So if you are interested in understanding how vitamin D can help you, keep reading. 

Vitamin D And The Immune System

Vitamin D does seem to have a promoting or boosting effect on the immune system.  It helps the body respond to active infections like viruses, bacteria, and fungus.  It also helps with modulating and balancing the immune system in those people with inflammation and autoimmunity.  Below we will get into a lot more details on how this works.  First a little immune system background. 

There are two different aspects of our immune system one is called the innate immune system and the other is the adaptive immune system.  The innate immune system is a group of cells that initially will detect pathogens and other problematic proteins that our bodies might come in contact with.  This part of the immune system is considered the first line of defense.  This group of cells consist of things like macrophages and monocytes.  These cells will basically engulf any dangerous substance or actual pathogen.  When they engulf the substance they digest it and present pieces of that pathogen or protein.  The cells put the protein on their surface to communicate with the other parts of the immune system what that cell has encountered.  This is called presenting the antigen or antigen presenting.  Vitamin D  enhances this function in macrophages and other innate immune cells. 

In summary, it enhance in the ability of the cells to find and actually engulf any pathogens or potentially problematic thing they see. The net result is enhanced detection and removal of bacteria, viruses, fungi, and other potentially harmful substances. Here is a link to an article describing Vitamin D's role in immune function in more detail. 

The Role of Vitamin D on Adaptive Immune Function

The adaptive immune system is responsible for producing antibodies and different lines of T lymphocytes.  Vitamin D's role in the adaptive immune system is less clear than it is in the innate immune system. This is partially because there are more layers to the adaptive immune system making it herder to study.  Overall vitamin D does seem to have a modulating effect on the various arms of the adaptive immune system. 

The adaptive immune system consists of things like the B cells which produce antibodies.  It also involves the T cells which find, isolate, and kill specific pathogens that are identified by antibodies.  Within the T cells there are different cell lines that can be differentiated.  All T cells start the same, as a basic T cell.  Based on what the immune system is seeing, like immune chemicals, the T cells will differentiate into a different lines of T cells.  The role of Vitamin D is to provide some balance or modulation to the T cell line development. 

With autoimmune disease the balance in T cells is shifted and so are the immune chemicals. This is responsible for the increased inflammation.  Vitamin D can dampen that effect through its effect on other another type of T cell called a T regulatory cell.  Vitamin D enhances these T regulatory cells.  Overall the consensus on vitamin D's role in the adaptive immune response is not as clear.  However it does seem to nullify any excessive inflammation and autoimmune activity that might be going on. 

The Role Of Vitamin D In Infections

An interesting thing to note about the role of vitamin d in helping the immune system, is its role on respiratory tract infections.  There are multiple studies over the years that have looked at this.  A review study looked at the role of vitamin d and preventing or reducing respiratory tract infections in general. 

"It appears that vitamin D may represent a novel and safe indication for preventing respiratory tract infections. In addition daily or weekly doses seem to more to be more efficient than pulse therapy. Individuals with lower levels of vitamin D may benefit more from the supplementation."

They're saying pulse therapy would be like giving a really large dose one or two times versus daily doses or even weekly doses.  Similarly it is better to keep your vitamin d levels within range consistent over time versus always chasing it.  It also makes sense that those with the lowest levels of vitamin D benefit most from supplementation. 

So this leads to the question, what are the therapeutic benefits of vitamin D supplementation, on the immune system, when vitamin D levels are already sufficient?  The data on that is is lacking at this point. 

There does seem to be a benefit in taking vitamin D for immune support in different scenarios like:

• When you are actually low.
• Sort term when you are sick.
• When your body has more inflammation.

As far as the inflammation side, vitamin D is going to get converted and used up quicker.  As a result,  you may need to supplement with vitamin D.  The inflammation is more in reference to having a blood test showing high inflammation.  If you feel a joint pain or something, that doesn't necessarily mean you have inflammation.  Typically if you have autoimmune disease you will have high inflammation. 

The point is you should verify if you have inflammation with a blood test.  Similarly you should be carful with vitamin D supplementation because too much can be harmful.   You can check your vitamin D status.  Once you check and you are low in vitamin D, it is very safe to supplement with.  It appears from multiple research studies and both in humans and test tube studies,  that vitamin D has a positive affect on different immune cells.  Vitamin d has a beneficial effect in preventing cold flus and overall helping the immune system be more balanced. 

That should give you a better understanding of the role of vitamin D in your immune system and health.  If you have any questions on the contents of the article, please ask in the comment section.  If you need help navigating your vitamin D levels, or optimizing your immune health, click on the link below to get started.