I still wear a hat, or cover up entirely if I will be out all day, but the fern based pills like helicare or solaricare or whatever seem to prevent me from burning, or even reverse a mild burn if I take it fast enough. I have no idea if it is preventing dna damage that would lead to cancer. But I get a little tan by the end of the summer. And I've never done that before. My dermatologist recommended it so it must be fine...
Judging by the amount of people that are Vitamin D deficient according to the medical community, makes me really wonder if the medical community would think twice about giving you tips that make you continue being vitamin D deficient. It doesn't seem to be important to them.
AFAICT there is no scientific evidence of people actually getting vitamin-D deficiency from sunscreen use.
Even with really powerful sunscreen, every second you're exposed some portion of those UV-B wavelengths are still getting through to catalyze the production of Vitamin D.
According to one study [0] on a sunny summer day in Spain you could have 25% of your skin exposed and only need 7 minutes for that day's vitamin-D needs. (Obviously longer in dimmer conditions and wintertime, but those aren't the times people are going to slather sunscreen everywhere either.)
Because there are other seasons, climate types, latitudes, skin colours, and there are a ton of people who rarely, if at all go outside, especially those who have panic, stress, or anxiety disorders.
Also, of course, there is a variability between people how much vitamin D they can produce, but we have no real clue about the causal connections there, but so far it seems that it’s way less important than other factors generally speaking, especially in the context of “many people”.
To add to this, you should also be getting regular (like twice a year) blood draws done to check where all your nutrient levels are. This way, you can decide which supplements and how much.
Through this, I've learned that my Vit. D supplement works. My multivitamins work, and my B12 supplements work. My previous iron supplement was not working, and I was able to make a change to a different product. Then, six months later, a blood test showed my iron levels back in the normal range.
Honestly, I love comments like this to remind me that HN posters have massive blind spots in knowledge that most people would assume are almost common knowledge for an adult. But beyond that, in the face of seeing 90% of the answer presented in front of you by the prior commenter, where you could basically infer that there must be some be some benefit to taking both, instead of googling it prior to a comment, you reply back with a snide comment assuming the prior poster is a total fool.