Updated: Jun 11, 2020
Vitamin D plays an important role in modulation of the immune system responses to respiratory viral infections, vitamin D deficiency is associated with increased risk of respiratory infection.
It is not known whether vitamin D supplementation could be used as an acute treatment in a pandemic like the current one. However we do know that people lacking vitamin D have a weaker innate immune defence against viruses such as SARS-CoV-2.
Vitamin D deficiency has been shown to increase risk of acute respiratory distress syndrome (ARDS) with a very high prevalence of deficiency found in patients with ARDS – (it is the ARDS which puts the COVID patients into the intensive care unit, in need of a ventilator).
Vitamin D deficiency exacerbates inflammation, epithelial damage and hypoxia. Repletion of vitamin D to those who are deficient improves lung function. A large 2019 meta-analysis also showed that there is increased risk in pneumonia for those who are vitamin D deficient.
How much vitamin D should I take?
As a general recommendation - Vitamin D supplementation at 2-5000iu a day for adults is usually appropriate (see link), however ideally it is best to get your vitamin D levels tested by means of a finger prick test in order to establish the vitamin D requirements.
Can I get my vitamin D levels tested?
Vitamin D levels can be ascertained by means of a finger prick test which can be done at home using a kit. The blood sample is sent to the laboratory and the results are usually accessible within 48 hours. The test is around £50.