Posted on

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.