My doctor added vitamin D test to his patients recurring blood work since the start of COVID, and found out just about all his patients was deficient or near it.

If you don't have a primarily fish based diet or spend hours under direct overhead sunlight every day without a shirt on, you're probably deficient as well.

That's a bit of an exaggeration, Vitamin D does not require hours in the sun:

> Recommendations to Obtain Adequate Amount of Vitamin D.

> Sun exposure to the face, arms, hands, and legs without sunscreen for 5 to 30 minutes at least twice a week or more between the hours of 10 am and 4 pm

Source: https://pmc.ncbi.nlm.nih.gov/articles/PMC8299926/

Now that's for most people: if you live in Alaska then during the winter maybe you need a litle more or something ... but the point is most people just need a little sun, < 30 minutes twice a week.