Keeping in mind that sunlight on the skin, absent any sunscreen of course, will use cholesterol in the body to make D3....interesting connection is that I have read many places PWP have low cholesterol. Can they not make enough D3 of their own, because they don't have enough cholesterol to make it, assuming they get out in the sun enough? I have not read of many parkies with high cholesterol, but am willing to be educated. Most statistics, if you can call them that, are that PWP have low D3 as well as low cholesterol.

The darker our skin is naturally, and the older we get, the longer exposure we must have to direct sunlight in order to make D3. I don't know how much time in the sun is enough time, but if you sunbathe like my grandma did, who was from "the old country", you'll roll up your sleeves and pant legs and sit in the sun a couple of times a day for 15-20 minutes, longer in the winter for some reason. She lived 30 days shy of 100, without any major disease. She never used sunscreen in her life and believed the sun was healing. Oddly, she never had any issue with skin cancer, either.

If you also take D3 supplements you may not need as much sun, but I would think the D3 we make naturally would be superior to canned D3, assuming the body can make it....a good excuse to eat a fatty steak and fries.