The importance of vitamin D in supporting the immune system

Researchers from The Irish Longitudinal Study on Ageing (TILDA) have released a crucial report which shines a light on the role of vitamin D and unveils shocking levels of deficiency in older people in Ireland. The team, based at Trinity College in Dublin, concluded that Vitamin D supplementation was necessary for those over the age of 50 and those currently shielding. They also highlighted a range of studies showing vitamin D plays a role in the prevention of respiratory infections, boosting the immune system response to infections and reducing the need for antibiotic use. 

The study, titled Vitamin D deficiency in Ireland – implications for COVID-19, used data from wave 1 of The Irish Longitudinal Study on Ageing (TILDA), which started back in 2009. This was a prospective study of 8,172 adults aged 50 years and older in Ireland living in the community – not in care homes or hospitals. The participants were personally interviewed and their answers on their socio-demographic status, physical, mental and behavioural health recorded. 72% of the participants consented to a health assessment and of those, 91% submitted a blood sample for vitamin D level assessment (5,382 people). 

The data revealed that of those aged 55+ years in the Republic of Ireland, 1 in 5 are vitamin D deficient during the winter and 1 in 12 during the summer. This rises to nearly 30% of those aged 70+ and 47% of those aged 85+. These are the age groups considered to be ‘extremely medically vulnerable’ to adverse health outcomes of COVID-19 and have been advised to participate in ‘cocooning’ (known as ‘shielding’ in the UK) during the pandemic.

The researchers also considered the findings of a range of medical studies into the role of Vitamin D in immune function and immune response to infection. One such study in 2017 carried out by Vanherwegen AS, Gysemans C, Mathieu looked at regulation of immune function by vitamin D and its use in diseases of immunity.

Principal Investigator of TILDA Rose Anne Kenny comments:

“We have evidence to support a role for Vitamin D in the prevention of chest infections, particularly in older adults who have low levels. In one study Vitamin D reduced the risk of chest infections to half in people who took supplements. Though we do not know specifically of the role of Vitamin D in COVID infections, given its wider implications for improving immune responses and clear evidence for bone and muscle health, those cocooning and other at-risk cohorts should ensure they have an adequate intake of Vitamin D.”

The researchers concluded that adults aged over 50 should take Vitamin D supplements, and not just in winter, but all year round if they don’t get enough sun.


Altruvita’s high quality Vitamin D supplement is from cholecalciferol and provides around 500% of the adult daily requirement for health.

Can Vitamin D help you right now?

As governments around the world battle the COVID-19 pandemic, public health measures that can reduce the risk of infection and death in addition to lockdowns and social distancing are desperately needed. Here at Altruvita we’re constantly reading about the latest clinical trials and studies looking at the impact of micronutrients, nutrition and vitamin deficiencies on health.

An article published by a team based in the US and Hungary reviewed the roles of vitamin D in reducing the risk of respiratory tract infections, knowledge about the epidemiology of influenza and COVID-19 and how vitamin D supplementation might be a useful measure to reduce risk. 

Vitamin D is already known to reduce risk of infections through several mechanisms. Those mechanisms include lowering viral replication rates and reducing concentrations of pro-inflammatory chemicals that produce the inflammation that injures the lining of the lungs, leading to pneumonia.

Evidence supporting the role of vitamin D blood levels in reducing risk of COVID-19 infection includes that fact that the outbreak occurred in winter, a time when vitamin D concentrations are lowest. Note that the number of cases now in the southern hemisphere near the end of their summer are low (for example in Australia, New Zealand and South Africa). Cases have been higher than in areas which are most likely to have vitamin D deficiency.

Vitamin D deficiency has been found to contribute to acute respiratory distress syndrome (ARDS); and that case-fatality rates increase with age and with chronic disease comorbidity, both of which are associated with lower 25(OH)D concentration. 

According to national surveys in the UK, across the population approximately 1 in 5 people are thought to have low vitamin D levels and are deficient (defined as serum levels below 25 nmol/L). Patients with levels 25 nmol/L to 50 nmol/L are classed as insufficient.

The UK has been lucky to enjoy sunny weather since the start of the lockdown, an end to the heavy rain of the winter just gone. Those of us who are lucky enough to be able to get out in our gardens or take a daily walk outside are now getting an opportunity to soak up some sunshine. Between late March/early April and September, the majority of people aged 5 years and above will probably obtain sufficient vitamin D from sunlight when they are outdoors, alongside foods that naturally contain or are fortified with vitamin D.

However, the authors of the review suggest that the goal should be to raise 25(OH)D concentrations above 100-150 nmol/L, which is way higher than just obtaining sufficient levels (anything over 50 nmol/L). The only way to achieve this fast enough during the peak of the this pandemic is to do everything – get out in the sun, eat vitamin D rich foods and take a supplement.

Some studies have reported that vitamin D supplementation reduced the risk of influenza, whereas others studies did not. To reduce the risk of infection, the authors of this paper advised that people at risk of influenza and/or COVID-19 consider taking 10,000 IU/d of vitamin D3 for a few weeks to rapidly raise 25(OH)D concentrations, followed by 5000 IU/d. For treatment of people who become infected with COVID-19, higher vitamin D3 doses might be useful. Randomised controlled trials and large population studies should be conducted to evaluate these recommendations.

Vitamin D supports the immune system.* Explore Altruvita’s Vitamin D supplement and the rest of our Immune Support range – just click hereOur Vitamin D is from cholecalciferol and provides around 500% of the adult daily requirement for health.

* EU REGISTERS ON NUTRITION AND HEALTH CLAIMS

Reference:

Grant WB, Lahore H, McDonnell SL et al. Evidence that Vitamin D Supplementation Could Reduce Risk of Influenza and COVID-19 Infections and Deaths. Nutrients. 2020 Apr 2;12(4). pii: E988. doi: 10.3390/nu12040988.