For example, vitamin D can be obtained with a walk in some sunshine and fresh air, or just sitting on your rocking chair on your porch. The sunshine provokes vitamin D synthesis in your body.
+++++++++++++++++++++++++++++++++++++++
That would be a “no”, it’s not that easy to get.
If you want the truth about getting Vit D, check this out .... researchers, not supplement sellers. This is pretty much “everything D”, not just in relation to COVID.
Vitamin D for Covid, What’s the Catch? - DarkHorse Podcast Gruff Davies and Linda Benskin
https://www.youtube.com/watch?v=8LFkWiNP1wQ
Dr Ryan Cole says that it’s hard to get D from the sun up North and in most places in winter.