This will be short and sweet because I don’t want to dilute the point. Since early days with Covid-19 there has been suspicion around a certain nutrient playing a very protective role for people around the virus. This was based on the characteristics of people who well becoming really unwell, and unfortunately some passing away, and those who were getting milder symptoms (https://www.thelancet.com/journals/landia/article/PIIS2213-8587(20)30183-2/fulltext). Suspicions have been recently supported by the results of a small but high quality study in Spain. (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7456194/).
Adequate vitamin D levels may protect us from becoming very unwell with Covid-19.
Vitamin D is a nutrient, and for most of us, we will get most of the vitamin D we need through making it ourselves when sunlight hits our skin rather than from our diet (https://pubmed.ncbi.nlm.nih.gov/11700831/). Thus, having adequate vitamin D levels depends on us getting enough sun exposure. In Melbourne we know that almost half of us will have low vitamin D levels by the end of winter (https://pubmed.ncbi.nlm.nih.gov/11700831/). It makes me sit back and wonder if there is any relationship between the very place in Australia that is still struggling with Covid-19 and the place where winters are long and cold (excepting the amazing island of Tassie which has done well during Covid-19).
The key question is how do we balance getting enough sun exposure for adequate vitamin D levels while still being Sun Smart? Osteoporosis Australia have updated their guidelines to answer exactly this question and it can be found at: https://www.osteoporosis.org.au/new-recommendations-sun-protection-and-vitamin-d They recommend that when the UV rating is 3 and above, the sun protection is the priority, while at lower ratings, sun exposure for vitamin D may be helpful. Another great resource is the SunSmart App, which you can download on your phone for daily notifications around UV levels and getting enough vitamin D.
For many of us, particularly those of us who really prioritise being Sun Smart, or spend a lot of time indoors or covering by clothing, and those of us with darker pigmented skin, vitamin D supplements may be a good option. Most vitamin D supplements in Australia are effective because they are made from cholecalciferol. There are occasions where supplementation of any nutrient isn’t considered safe, so a quick chat to your GP or Dietitian is a good place to start (https://www.thelancet.com/journals/landia/article/PIIS2213-8587(20)30268-0/fulltext).
In summary, adequate vitamin D levels seem to be protective around the Covid-19 virus and you can get there through sun exposure at Sun Smart low UV levels or perhaps through vitamin D supplements.
Enjoy the emergence of the warmer weather and I hope you stay safe.