Optimal Sun Exposure

When UVB shines on us, our skin produces vitamin D. Vitamin D is important in preventing heart disease and cancer, and gives us strong bones.

On the other hand, too much UVR may cause skin cancer.

So, how much sun exposure is optimal?

When UVB shines on us for 15 minutes, our skin can produce enough vitamin D that our health needs. So, 15 minutes sun exposure per day is optimal. It strikes a good balance between producing enough vitamin D and avoiding skin cancer.

For those 15 minutes, I think it is better to let the sun shine on our body (arms, legs, torso), instead of on our face. Sun damage is cumulative. Our face gets sun exposure all year round. So, over our lifespan, our face gets more sun exposure cumulatively than any other part of our body.

And for those 15 minutes, sunscreen should not be applied on the body, because the sunscreen will block UVB and interfere with our vitamin D production.