Researchers from Technological University Dublin (TU Dublin) and Trinity College Dublin (Trinity) have found that taking Vitamin D supplements may enhance resistance to respiratory infections such as Covid-19, or limit the severity of the illness for those that do become infected. Dr Daniel McCartney (TU Dublin) and Dr Declan Byrne (St. James’s Hospital and School of Medicine, Trinity), co-authors of the article published in the Irish Medical Journal on Friday, recommend that adults living in Ireland take 20-50 micrograms of vitamin D per day.

Historically, humans received most of their vitamin D from sunshine during the summer months, with diet contributing only very modest amounts in relation to overall needs. In recent decades, sun exposure has decreased, and many people in Ireland may consequently have low blood levels of vitamin D, with older adults, especially likely to be vitamin D deficient.

Speaking about the findings, Dr Daniel M. McCartney, Lecturer in Human Nutrition & Dietetics, Technological University Dublin, said, “Vitamin D deficiency is prevalent in Ireland, especially in older people, nursing home residents and hospital inpatients, and may significantly increase the risk and severity of viral respiratory infections, including Covid-19.

Supplementing a healthy diet with 20-50 micrograms per day of vitamin D represents a cheap, safe and potentially very effective protection for Irish adults against Covid-19.” Dr Declan G. Byrne, Clinical Senior Lecturer, St James’s Hospital and School of Medicine, Trinity, says these recommendations are important while we await development of a vaccine and trial evidence of effective drug treatment for Covid-19. “Our findings call for the immediate supplementation of all hospital inpatients, nursing home residents and older Irish adults with vitamin D. Our findings also suggest that vitamin D supplementation in the broader adult population, and particularly in frontline healthcare workers, may further help to limit infection and flatten the Covid-19 curve.”

The Irish Society for Clinical Nutrition and Metabolism (IrSPEN) welcome what they see as sensible advice for those at risk and the Irish Pharmacy Union (IPU) is publishing them to their 2,300 members working in the nation’s 1,800 plus pharmacies. Existing national and international guidelines from health authorities also already advise that older adults should supplement their diet with vitamin D.

Supplementation at the recommended 20-50 micrograms of vitamin D per day is a short-term measure to specifically address the risk of Covid-19 infection over the coming 3-6 months. It is advised that those who intend to supplement at doses above 20 micrograms per day after this period, should do so only under the supervision of their doctor.


Read Irish Medical Journal publication here

A Healthcare Professional summary of – Optimisation of Vitamin D Status for Enhanced Immuno-protection against Covid-19 – is available here.