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This is not a direct answer, but: 1. Uva is the cause of most skin cancer 2. Uvb generates vitamin d and sunburns 3. When uvb is present, you can make suffic
by graeme 6y ago
This is not a direct answer, but:
1. Uva is the cause of most skin cancer
2. Uvb generates vitamin d and sunburns
3. When uvb is present, you can make sufficient vitamin d quite quickly
This would suggest you would want sunscreen for longer exposures, or with much uva exposure. And could get vitamin d from a briefer exposure pre sunscreen.
I can’t say how completely sunscreen blocks vitamin d however.
- dralley 6y agoGiven that sunburn is a response to cellular damage of your skin cells, why would it be the case that the two are de-coupled w/r/t UVA and UVB?
- graeme 6y agoActually, it seems I was wrong. I thought it was just UVA, but uvb also causes melanoma. I’d delete the above comment if I could. The main point that you can get vitamin d from short exposure without sunburn is correct, but I was incorrect on the risk. But he fact I was wrong about uvb and melanoma also makes me think I may be incorrect on the risk of uva during periods without uvb. https://en.wikipedia.org/wiki/Melanoma#UV_radiation https://en.wikipedia.org/wiki/Melanoma#UV_radiation