How to boost your immune system with Vitamin D

What can I do to support my immune system?

There has never been a better time to make sure your immune system is functioning optimally. The immune system is your main line of defence against viruses, and immune health relies on an adequate intake of vitamins and minerals.

While there is not currently a vaccination for COVID-19, there are simple ways you can support your immune system through the diet and supplementation. Vitamins and minerals play vital roles in immune defence and deficiencies in some reduce your body’s ability to fight off infections.

Vitamin D is of particular interest since a deficiency is associated with autoimmune conditions, demonstrating how critical a role it has in the function of the immune system. Additionally, a deficiency confers increased susceptibility to infections with similar symptoms to COVID-19 [1].

What is vitamin D?

Vitamin D is a fat-soluble vitamin often associated with bone health. Vitamin D levels in food aren’t naturally high, so foods like cereals are often fortified with vitamin D. However, it is difficult to get enough vitamin D from our diets alone. 

Fortunately, the body produces vitamin D upon exposure of the skin to the sun between April and September.

Despite this, vitamin D deficiency is one of the most common nutritional deficiencies in the world and one-quarter of the UK population are deficient in vitamin D [2].

How does vitamin D support the immune system?
When a virus enters the body and is recognised by the immune system, macrophages release pro-inflammatory molecules called cytokines. Vitamin D reduces cytokine production and thus decreases the detrimental effect of too much inflammation in the body [3]. 

Vitamin D also increases the production of antimicrobial agents in the body which have antiviral activity meaning they can inactivate viruses such as the influenza virus [4]. 
 Will vitamin D help my immune system?
Vitamin D has long been used to treat infections. Before the widespread use of antibiotics, vitamin D was used to treat tuberculosis. Recent studies have shown that supplementation with vitamin D reduces the risk of acute respiratory tract infections.

The lower your vitamin D levels are to begin with, the greater the benefit of supplementation [5]. Not only does a vitamin D deficiency increase the risk of respiratory tract infections [6], but it may also increase the severity of symptoms. One study even found higher mortality in patients admitted to intensive care units who were deficient in vitamin D, indicating that insufficient vitamin D can affect disease progression [7].

The best way to check you have healthy levels of vitamin D is by a simple finger-prick blood test. Order our home diagnosis kit today for fast results atruchecks.com/test/health-checks/vitamin-d-25-oh.

References
1.    Thomason, J., Rentsch, C., Stenehjem, E. A., Hidron, A. I. & Rimland, D. Association between vitamin D deficiency and methicillin-resistant Staphylococcus aureus infection. Infection (2015) doi:10.1007/s15010-015-0815-5.
2.    The National Institute for Health and Care Excellence. Vitamin D deficiency in adults - treatment and prevention. Clinical Knowledge Summaries (2016).
3.    Helming, L. et al. 1α,25-dihydroxyvitamin D3 is a potent suppressor of interferon γ-mediated macrophage activation. Blood (2005) doi:10.1182/blood-2005-03-1029.
4.    Cannell, J. J. et al. Epidemic influenza and vitamin D. Epidemiology and Infection (2006) doi:10.1017/S0950268806007175.
5.    Martineau, A. R. et al. Vitamin D supplementation to prevent acute respiratory tract infections: Systematic review and meta-analysis of individual participant data. BMJ (2017) doi:10.1136/bmj.i6583.
6.    Ginde, A. A., Mansbach, J. M. & Camargo, C. A. Association between Serum 25-hydroxyvitamin D level and upper respiratory tract infection in the Third National Health and Nutrition Examination Survey. Arch. Intern. Med. (2009) doi:10.1001/archinternmed.2008.560.
7.    Matthews, L. R., Ahmed, Y., Wilson, K. L., Griggs, D. D. & Danner, O. K. Worsening severity of vitamin D deficiency is associated with increased length of stay, surgical intensive care unit cost, and mortality rate in surgical intensive care unit patients. Am. J. Surg. (2012) doi:10.1016/j.amjsurg.2011.07.021.