Professor James Bernard Walsh:

I would add to what Professor Kenny said. The safety of vitamin D is well recognised. She said that we recommend 800 to 1,000 international units. That is what we give to our bone patients but it is recognised by the Institute of Medicine that safe levels can be up to 4,000 per day. This is really to emphasise what Professor Kenny said. In addition to the recent longitudinal study with which Professor Kenny was involved and which she quoted to the committee, we also have the study involving 36,500 people in the Dublin metropolitan area published last August that showed that 70% of people living in the Dublin metropolitan area, Kildare and Wicklow are insufficient or deficient in vitamin D during the winter, which is a significant percentage, and 30% are insufficient or deficient all year round. When it comes to people in the Indian community at whom we have looked, only 17% of them are sufficient and that is the same throughout. They do not change in summer or winter. That is very important.

We know also that some people who develop Covid-19 get neurological problems. We have seen this in young children who have problems walking. Guillain-Barré syndrome was mentioned. There are neuropathies and, as we know, Guillain-Barré syndrome is a post-viral-type neuropathy so there are main neuropathies. This is not to say we have strong evidence that vitamin D affects that but we know the severity of disease with people who get Covid is more severe among those with very low levels of vitamin D. It is important they have vitamin D normalised a long time before they get Covid. One does not shut the stable door after the horse has bolted. We are still waiting for the evidence that this may be of value but we know that people with the severest form of the disease have the lowest levels of vitamin D. We have seen this in the BAME community.