Whilst there is currently little treatment for COVID-19, preventative measures such as wearing a mask, washing hands, and social distancing are helping to stop the spread of this virus. Another way you can help protect yourself from COVID-19 is to pay attention to your immune health, which is your body’s primary defence against infection and disease. Research evidence mounts that vitamin D plays vital roles in the correct function of our immune system and has been shown to help protect against upper respiratory illnesses.¹

Vitamin D

Vitamin D is a fat-soluble vitamin that is now understood to have wide-ranging effects on the body. There are two main forms: vitamin D₃ (cholecalciferol) and D₂ (ergocalciferol). Vitamin D₃ is synthesized in the skin by sunlight, and both vitamin D₃ and D₂ can be obtained from dietary foods, fortified foods, and food supplements. Dietary sources of vitamin D are found in oily fish such as mackerel and salmon, egg yolks, beef liver and some dairy products.²  However, it is recognized that dietary intake of Vitamin D is often not optimal and measurement of serum 25(OH)D concentrations is the best way of estimating vitamin D status. All adults living in the UK have been advised to take a daily supplement containing 400 international units (10 micrograms) of vitamin D throughout the year, including in the winter months.³

Does Vitamin protect against COVID-19?

Currently, medical research is investigating if a deficiency of vitamin D is related to the risk of contracting COVID-19, and we will have to wait for further evidence of this suspected link.  Other research has examined if Vitamin D deficiency is linked to the severity of COVID-19 once contracted, which concluded that there was evidence to support this theory. This is especially concerning given that many people are deficient in vitamin D, especially older individuals who are most at risk of developing severe COVID-19-related complications¹

What can we do?

 Though recommendations on what constitutes an optimal vitamin D level vary, the guidance indicates that vitamin D levels should be above 50 ng/mL in the UK. Depending on your blood levels of vitamin D, further supplementation above the recommended standards may be necessary. However, it can be challenging to estimate your vitamin D levels without testing and so it is advisable to seek advice from your healthcare practitioner regarding this and supplementation recommendations.

1. Mohan, M., Cherian, J. J. and Sharma, A. (2020) ‘Exploring links between vitamin D deficiency and COVID-19’, PLoS pathogens. Public Library of Science, 16(9), pp. e1008874–e1008874. doi: 10.1371/journal.ppat.1008874.
2. Elorinne, A.-L. et al. (2016) ‘Food and Nutrient Intake and Nutritional Status of Finnish Vegans and Non-Vegetarians’, PloS one. Public Library of Science, 11(2), pp. e0148235–e0148235. doi: 10.1371/journal.pone.0148235.
3. https://www.nhs.uk/conditions/vitamins-and-minerals/vitamin-d/