Harvard Health has recently published an article which discusses treatments for COVID-19 on what helps, what doesn’t help and what’s a potential therapeutic.¹ At Gr8 Health, we believe that physical exercise, adequate sleep, well-balanced diet, and hydration are all important aspects of maintaining good health and preventing disease. Complementary health can support the conventional medicine model in encouraging the individual to take charge of their health to improve health outcomes throughout their life. Despite what path you decide to take when it comes to protecting yourself against COVID-19 or its potential long-term side effects, arming yourself with a robust immune system will always be beneficial.

What increases the risk of serious adverse effects of COVID?

Some people are more likely than others to become severely ill with COVID-19, including older adults, certain ethnic groups, pregnant women, and those with medical conditions. People who have Type 2 Diabetes, heart conditions, liver disease, or are overweight or obese have increased risk of hospitalization and mortality.² Lifestyle, metabolic disorders and immune status all seem to have an enormous impact on the severity of, and recovery from, COVID-19.³ Data shows that as Body Mass Index (BMI) increases, so does the risk of diagnosis of COVID-19, complications and mortality.⁵ Therefore, it is important to consider the impact that lifestyle and dietary choices may have on individual health outcomes. With this, it is important to note that systemic health and social inequalities have a large part to play in increasing risk.⁴

Having a well-balanced diet is a key determinant in improved immune function against infection in general, with poor nutrition significantly weakening the immune system.³ There are many nutrients involved in immune function, such as vitamin C, zinc, and Vitamin D that we can receive through improved dietary and lifestyle practices.⁶

Vitamin D and COVID-19

Vitamin D plays a key role across many systems of the body, with one of it’s key functions being to modulate the immune system. Vitamin D and its metabolites can stimulate antimicrobial proteins and enhance autophagy, combat pathogens, and reduce viral infections. Vitamin D also mediates immune T-cell responses which can reduce inflammation.⁷

Low levels of serum Vitamin D enhances the risk of both upper and lower respiratory tract infection, with blood levels of >95nmol/L of Vitamin D significantly reducing the rate of acute viral respiratory tract infections.³ Research has found that there is increased prevalence of people who are in hospital with severe COVID-19 that have Vitamin D deficiencies. ⁸ Although, the risk factors for development of severe symptoms from COVID are the same as for those developing vitamin D deficiency (i.e. poor diet, diabetes, liver/kidney disease), which must be considered.⁸

From a quick review, current research has mixed results. One systematic review concluded that blood vitamin D status can determine the risk of infection, serious complications, and mortality from COVID-19.⁹ Pooled analysis in another systematic review found that those who were vitamin D deficient had an 80% increased risk of infection compared to those who have sufficient Vitamin D levels.¹⁰ Although, studies measuring the benefit of supplementation with those who have active COVID-19 infection remain inconsistent and insufficient.⁸

Harvard Health made the following statement:

There is some evidence to suggest that vitamin D might help protect against becoming infected with, and developing serious symptoms of, COVID-19. We know, for example, that people with low vitamin D levels may be more susceptible to upper respiratory tract infections. One meta-analysis found that people who took vitamin D supplements, particularly those who had low vitamin D levels, were less likely to develop acute respiratory tract infections than those who didn’t.Vitamin D may protect against COVID-19 in two ways. First, it may help boost our bodies’ natural defense against viruses and bacteria. Second, it may help prevent an exaggerated inflammatory response, which has been shown to contribute to severe illness in some people with COVID-19.

• Harvard Health, 2021

Therefore, although supplementation of Vitamin D may not cure COVID-19 infection, maintaining your levels year-round is not only beneficial for multiple body functions, it also improves immune responses to reduce risk of infection, serious complications, and mortality.

Naturopathic principles state that prevention is greater than cure. Optimising your Vitamin D status can be a simple (and easy!) tool to boost your immune system, thereby potentially reducing risk of COVID-19. Furthermore, the British Journal of Nutrition also suggested that ensuring nutritional adequacy can also optimise vaccine efficacy, particularly in vulnerable populations.¹¹

How to improve Vitamin D levels

Luckily for us, our bodies manufacture its own vitamin D when it’s exposed to sunshine. The amount of sun exposure needed depends on your skin colour, where you live and the time of year. As a general guide, it is best to expose your face, arms, hands, or legs for:

• 10 minutes in summer
• 5-20 minutes in spring and autumn
• 30 minutes in winter

Dietary sources of Vitamin D are limited and includes fatty fish such as salmon, tuna, sardines, and mackerel. There are small amounts in grass fed beef, cheese, and egg yolks. It is important to note, Vitamin D is a fat-soluble vitamin, which means a diet low in fat may reduce its absorption.

Vitamin D is stored in the body for around 2 months. Therefore, the Vitamin D you stocked up during the summer months will start fading away as the shorter and colder months roll in. Since it is hard to get adequate Vitamin D from food alone, you may want to consider supplementation.

Before supplementation, it may be useful to speak to your GP to order a blood test to determine your current levels of Vitamin D. The reference ranges for Vitamin D are 50-150, although ideally you would want them to be above 100nmol/L.³ A daily supplement for most adults* of 1000IU to 2000IU is likely a safe and effective in improving vitamin D status. You can find our range of Vitamin D supplements here.

No content on this site, regardless of date, should ever be used as a substitute for direct medical advice from your doctor or other qualified clinician. *Before taking any new supplement please consult with a health care provider for dosage, interactions with medications and health risks.

¹ https://www.health.harvard.edu/diseases-and-conditions/treatments-for-covid-19

² https://www.cdc.gov/coronavirus/2019-ncov/need-extra-precautions/people-with-medical-conditions.html

³ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8287001/

⁴ https://www.cdc.gov/obesity/data/obesity-and-covid-19.html

⁵ https://www.obesityevidencehub.org.au/collections/impacts/impact-of-obesity-on-covid-19-outcomes

⁶ https://www.health.harvard.edu/blog/do-vitamin-d-zinc-and-other-supplements-help-prevent-covid-19-or-hasten-healing-2021040522310

⁷ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7461279/

⁸ https://www.cochranelibrary.com/cdsr/doi/10.1002/14651858.CD015043/full

⁹ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7800698/

¹⁰ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7973108/

¹¹ https://www.cambridge.org/core/journals/british-journal-of-nutrition/article/optimising-covid19-vaccine-efficacy-by-ensuring-nutritional-adequacy/5F25F117DED5141638554BAAFC66E1FF