Sunscreen does reduce vitamin D, but don’t skip it.

Yes, it does—technically. Sunscreen blocks UVB rays, which are the ones your skin uses to make vitamin D. But the practical effect is small for most people.

The reason: you’d have to apply sunscreen perfectly and completely to block all UVB. Nobody does that. Miss a spot, sweat it off, forget to reapply—your skin still gets some exposure. Studies show that regular sunscreen users generally maintain adequate vitamin D levels.

And the trade-off isn’t even close. Skin cancer is real. Vitamin D deficiency is easy to fix with a supplement or a few minutes of unprotected sun before you apply sunscreen (if you really want to optimize). The sun is not a reliable vitamin D delivery system anyway—it depends on latitude, season, skin tone, and time of day.

Stop worrying about this. Wear sunscreen. Take a vitamin D pill if you’re concerned. The perfect amount of sun exposure for vitamin D is about the same amount that gives you a sunburn, and that’s not a good game plan.