How to Improve your Immune System with a Vitamin D3 Supplement
Improve your Immune System with a Vitamin D3 Supplement

How to Improve your Immune System with a Vitamin D3 Supplement

Has there ever been a time when the function of your own immune system has been more important to you than now? As we learn more about the Covid-19 pandemic, and look closer at the data we are realising that individual immune system function, and even a vitamin D3 supplement, really matters:

“Despite difficulties in comparing data across nations, mortality from COVID-19 is clearly higher in some countries than in others. Many factors could have a role in this disparity, including differences in proportion of elderly people in a population, general health, accessibility and quality of healthcare, and socioeconomic status. One mostly overlooked factor that could influence outcome of COVID-19 is the relative vitamin D status of populations.”

Vitamin-D and COVID-19: do deficient risk a poorer outcome? Fiona Mitchell, May 20, 2020, The Lancet.

The vitamin D3 supplement example 

In the wake of Covid-19, suddenly we have been forced to stop and think, often for the first time, about how well our own immune system would cope if we contracted the virus. Would we be ok? How about our family and friends? How can we tell, and how can we improve our body’s own defences. Determining our vitamin D3 status is certainly a good place to start, and if we discover we are deficient (in the case of Covid-19 it has been suggested that below 25 nmol/litre may be an additional risk factor), a vitamin D3 supplement should be first on our list. In fact, we really shouldn’t wait to be anywhere near deficient, as it is now so simple to test our own D3 level and many health benefits can result by maintaining a vitamin D3 level between 70-100 nmol/litre all year round, and often taking a vitamin D3 supplement is a great way to maintain this.

How does our immune system work?

Many cells and organs work together to protect us from invasion from foreign substances such as viruses, bacteria, parasites and unhealthy cells (known as antigens). The cells within our immune system are known as white blood cells, and there are two main parts to our immune system as follows:

  1. The Innate immune system – Our first line of defence against invasion. Includes our skin, hair, cough reflex and certain chemicals and cells. Phagocytes are an example of innate immune cells and their role is to engulf invading organisms. Natural killer cells are another example, and their role is to quickly attack invaders such as a virus. The main function of the innate immune system is to act immediately to prevent the spread of invasion throughout the body.
  1. The Adaptive immune response – (Also known as acquired immunity). The adaptive immune response is the body’s specific response to invasion. There are two kinds of cell that make up the adaptive immune system; B lymphocytes and T lymphocytes. Lymphocytes begin life in our bone marrow and either remain there to mature into B cells, or they travel to the thymus gland to mature into T cells. B lymphocytes serve as our body’s intelligence system, locating their targets and sending out defences to lock onto them. They make antibodies, which are specialised proteins designed to lock onto specific antigens. That way, if that antigen reappears later in life, the antibodies are ready and waiting. T lymphocytes are like the soldiers, and they destroy any invaders that the B lymphocytes locate. The main hallmark of the adaptive immune system is the capability of rapid lymphocyte expansion through cloning. This way, the two types of lymphocytes can expand from a few cells to millions, each designed to fight the same pathogen. The adaptive immune response is not immediate, but is long-lasting, highly specific, and sustained via memory T cells. 

How does the immune system respond to viruses?

Viruses require our cells in order to produce their own proteins. Viruses can only replicate inside cells and are usually very simple in structure, consisting of just two components; proteins and nucleic acid. Depending on their nucleic acid, viruses are classified as either DNA or RNA viruses.

Our immune response to a viral infection is carried out by lymphocytes. However, the number of lymphocytes that initially recognise a virus is very small. This is particularly true for a new virus such as Covid-19, which we have never encountered before. After a viral infection, what follows is a race between our adaptive immune system (B and T lymphocytes) and the invading virus, which is seeking to replicate itself within our cells. It can take several days before we have enough lymphocytes to fight back against a viral infection. In the early stages of a viral infection, we rely on our innate immune system to fight back to slow the spread of the virus. This is critical to allow our lymphocytes to multiply. After 3-4 days, there are enough lymphocytes to fight back against the virus, with our B lymphocytes locating virally infecting cells, and our T lymphocytes destroying the invading virus. 

The problem with chronic inflammation 

Inflammation is the body’s normal physiologic attempt to defend us against foreign invasion such as from a virus, bacteria or after an injury, so that repair can take place. Short lived inflammation is an essential and healthy response by our body, without which we would not be able to repair. However, the problems start to begin when inflammation persists and becomes chronic. In today’s world, chronic inflammation is such a prevalent problem that most chronic diseases have now been linked to it. Chronic inflammation can occur in the presence of an ongoing injury or infection, or if our immune system is unable to adequately fight back and overcome a foreign invasion.

Functional Medicine and a vitamin D3 supplement can help boost your immune system 

Pharmacology focuses on the consequences of injury and inflammation once it occurs in the body. Functional Medicine takes a different approach; It works upstream by addressing the underlying conditions that can initiate or aggravate an inflammatory response. This way, inflammation within the body can be dampened down before it becomes a persistent problem by identifying and avoiding exposure to specific triggers. Through Functional Medicine, we can also make appropriate modifications to an individual’s diet and lifestyle, plus appropriate supplementation, such as introducing a vitamin D3 supplement.  

Why the Wahl’s protocol can help you improve your immune system

If you feel that your immune system may be causing your symptoms, I would highly recommend reading the Wahl’s protocol by Dr Terry Wahls. It is one of the best books about health that I have read, and one that many of my clients have already found extremely helpful. The great part about the Wahls’ Protocol is that it is easy to follow, and is broken down into three levels depending on the severity of your symptoms. In my experience, the vast majority of individuals can gain tremendous benefit from just following the first level. 

Links to the Wahl’s Protocol book (1) and the very useful Wahl’s Protocol cookbook (2) are below. 

The Wahl’s Protocol 

Through her own experience of being confined to a wheelchair for four years due to multiple sclerosis, Dr Wahls utilised her clinical expertise to devise the ‘Wahl’s Protocol’, a diet and lifestyle plan that she used to reclaim her health and leave her wheelchair far behind. The Wahl’s protocol guides the reader through different levels of change, according to their symptoms. It emphasises the importance of removing the foods that can upset our immune system, and replaces those foods with the high quality nutrients and proteins that our immune system requires to function well. 


“Using clear language, Dr. Wahls teaches how our food and lifestyle choices create health or disease depending on our choices. For anyone suffering from autoimmune or other chronic health problems, this book will be life changing.”

Mark Hyman, M.D. #1 New York Times bestselling author of The Blood Sugar Solution.

Sam’s chosen daily supplements, nutrients and foods to improve immune system function (and combat inflammation):

Vitamin D3 2000-5000 iU – (My number 1 choice is a Vitamin D3 supplement by Metabolics. Claim 10% discount with the promotional code 201697 – I suggest copying and pasting).

Vitamin D3 is one of the most important and powerful nutrients for supporting the immune system. Extensive research has shown that it can help reduce the risk of virus infection.

Vitamin C 500-1000 mg  Vitamin C may help to prevent infections, including those caused by bacteria and viruses. 

Vitamin A 10,000 iU – Short term vitamin A use can be extremely helpful in supporting the body’s ability to fight infections, particularly with regard to respiratory infections.

Zinc 30 mg –  Zinc plays a significant role in boosting immunity and reducing the number of infections we experience. It can also help when taken within 24 hours of symptom onset.

Selenium – Selenium is a key nutrient for immune function, and is also an antioxidant that helps boost our defences against bacteria and viruses.

Raw Honey – Raw honey has antioxidant properties, and also some antimicrobial effects making it helpful for coughs and sore throats. 

Curcumin 1000 mg daily   Curcumin is a potent anti-inflammatory and antioxidant and as a result, this list would not be complete without it.

Quercetin 500 mg (3x daily) – Quercetin has been shown to have antiviral effects and also acts as an antioxidant and anti-inflammatory.

Garlic – Garlic supplements may help to reduce the severity of viral upper respiratory infection and also play a role in the prevention of virus infection. 

Probiotics – Research has shown that good quality probiotics can help decrease the number of respiratory infections we experience, ands can be particularly helpful in children.

If you are looking to strengthen your immune system against the threat of infection there is a great deal you can do, such as introducing a vitamin D3 supplement. To learn more about how Functional Medicine could help you, please do not hesitate to contact me. Alternatively, you can arrange your