Some people, especially those with darker skin living outside the tropics during winter months, find it impossible to maintain the recommended blood levels just by eating good food. While overdosing can be dangerous, that would take a pretty extreme amount of supplementation for most people.

If you want to go the "natural" route then you need to have significant direct sunlight exposure.

Doesn't have to mean tanning for half an hour. But more than walking to your car.

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.