COVID-19 + Vitamin D: The science behind the hype

COVID-19 + Vitamin D: The science behind the hype

We explain the role Vitamin D actually plays in our health and what you can do to support its immune-boosting benefits.

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With so much information flying around from both credible and less credible sources, it's important to base our health decisions on facts. Our founder Jules addressed Vitamin D and its role in protecting our health on Sky News, speaking live to Gamal Fahnbulleh for The Early Rundown.

There is some evolving data (at the time of publishing this article) that shows a pattern between those suffering with severe COVID-19 symptoms and Vitamin D deficiencies. As with most COVID-19 research, the data is new and therefore not 100% reliable due to the presence of many other variable factors, like diet and underlying conditions.

At last count, Vitamin D insufficiency (where levels are below the optimum supply) affects almost half of the globe’s population, with an estimated 1 billion people worldwide across all age groups and ethnicities having a Vitamin D deficiency (where levels are significantly below the optimum supply). Those most at risk from Vitamin D deficiency are people with darker skin, a US study found that 41.6% of adults in the US are deficient. This number goes up to 69.2% in Hispanics and 82.1% in African-Americans. Often referred to as a pandemic in itself, deficiency can lead to a host of health problems, with research supporting the possible role of vitamin D against cancer, heart disease, fractures and falls, autoimmune diseases, influenza, type-2 diabetes and depression.

The British Medical Journal published a study in 2017, finding Vitamin D supplementation to help protect against acute respiratory tract infection. Although similar findings that support this are recommended to be approached with caution, this study has been sourced to tenuously suggest that it may effectively save us from coronavirus; however it’s important to consider established facts and not just the mostly assumed relationship between Vitamin D and this new specific disease.

Vitamin D is an essential vitamin which impacts multiple functions in your body. Unlike any other vitamin, it actually functions like a hormone and every single cell in your body has a receptor for it. In addition to its vital role in brain function and helping to prevent depression, Vitamin D plays a critical role in our immune response; it has anti-inflammatory properties and is crucial for the "activation" of immune defences. It is proven to enhance the function of immune cells, including T-cells, that protect your body against disease-causing pathogens. It’s also essential in regulating the absorption of key minerals such as calcium and magnesium. 

Vitamin D occurs in certain foods, like fatty fish and fortified dairy products, though it's very difficult to get enough from diet alone. Reports show that almost 70% of vegans and 40% of meat-eaters have low levels of Vitamin D. Our bodies make Vitamin D from cholesterol when we’re exposed to sunlight, hence it’s “sunshine vitamin” nickname, but lack of time outdoors (especially during lockdown) and other factors prevent this being a totally adequate source for most people.

Supplementing diet and sunlight exposure with Vitamin D is recommended by Public Health England and the NHS. Vitamin D is more than just one vitamin; it’s a family of nutrients that share similarities in chemical structure. In your diet, the most commonly found members are vitamin D2 (which can be found in mushrooms and fortified breakfast cereals) and D3 (found in oily fish, liver, egg yolks and butter). While both types help you meet your vitamin D requirements, the liver metabolizes vitamin D2 into 25-hydroxyvitamin D2 and vitamin D3 into 25-hydroxyvitamin D3. These two compounds are collectively known as calcifediol.

Calcifediol is the main circulating form of vitamin D, and its blood levels reflect your body’s stores of this nutrient. For this reason, vitamin D status can be determined by measuring your levels of calcifediol. Most studies show that vitamin D3 is more effective than vitamin D2 at raising blood levels of calcifediol, with one study in 32 elderly female patients finding that a single dose of vitamin D3 was nearly twice as effective as vitamin D2 at raising calcifediol levels.

Based on this research, you may want to consider supplementing with Vitamin D3 to effectively raise your blood levels of calcifediol, not just during the coronavirus pandemic, but for general health and wellbeing year-round.

And what else can you do during this time? Like a shield of armour, DEFENCE DROPS use a blend of adaptogenic herbs and immunomodulating extracts with naturally antibacterial, antiviral and antifungal properties to support your immune response at first signs of illness or at times when exposure to pathogens is higher, like in enclosed public places. For general health maintenance, our medical advisor Dr. Tiffany suggests the fundamental tools of health in addition to supplementing with Vitamin D and C: “Prioritizing eating 7-9 servings of fruits and vegetables a day to load up on immune-boosting antioxidants is key. Ensuring you are getting at least 7 hours of sleep every single night so that your body can rest and detox is essential.”


Our VITAMIN D sublingual spray uses Vitamin D3 to provide over 300% of Vitamin D RDA in 3 sprays. We have created this to supplement the primary sources of Vitamin D, diet and sunlight exposure, to ensure our immune system gets the amount it needs as recommended by official health bodies.