Best is probably none, just don’t over due the sun. There was a meta study a few years back, our sunscreen usage keeps going up, but so does our skin cancer rate. The main theory is that sunscreen probably doesn’t block the part that causes cancer, but by keeping you from getting burned is does prevent your body’s early warning system that tells you to get out of the sun before you get cancer.
With a quiet sun, has anyone undertaken a recent sunlight exposure study, which accounts for a reduced amount of UV consequent the reduction of sunspots?