I was tested recently and my doctor said I had dangerously low Vitamin D. It was so low they were going to proscribe high dose supplements. I eat very healthy, mostly salads and a bit of dairy and fish here and there. I bet a lot of people didn't get enough sunlight during covid. Also people with darker skin need more sun exposure to get enough. (Among Black people in snowy climates something like 70% of the population have a Vitamin D deficiency)

If you take over-the counter supplements and follow the instructions you're unlikely to overdose.