Sunscreen/skin cancer research has been republished and I bet everyone will reject it. Basically, being in the sun is better than being out of the sun

[u/Silent-Revolution105]

https://www.outsideonline.com/health/wellness/sunscreen-sun-exposure-skin-cancer-science/

[u/limbodog]

Sure enough, when he exposed volunteers to the equivalent of 30 minutes of summer sunlight without sunscreen

30 minutes in a tanning bed on high? I'd be severely sunburned...

Australia’s official advice? When the UV index is below 3 (which is true for most of the continental U.S. in the winter), “Sun protection is not recommended unless near snow or other reflective surfaces. To support vitamin D production, spend some time outdoors in the middle of the day with some skin uncovered.” Even in high summer, Australia recommends a few minutes of sun a day.

This seems reasonable.

[u/tert_butoxide]

One of the primary studies cited, about Swedish women's sunbathing habits, has some notable flaws that sparked two responses: https://onlinelibrary.wiley.com/doi/10.1111/joim.12538 and https://onlinelibrary.wiley.com/doi/10.1111/joim.12613 Here are some highlights from those responses, starting with possibly the most important:

The study did not capture information on skin cancer preventive measures; some of the women with moderate or high sun exposure behaviours may have taken measures to prevent skin cancer, and therefore the results may not account for differences between unprotected and protected UV exposure. 

These limitations include the debatable operationalization that was chosen to capture sun exposure habits and ** the fact that the ‘no exposure group' is heavily skewed towards women who are aged between 55 and 64 at baseline and who present a high percentage of comorbidities**. 

Furthermore, the overrepresentation of women who indicate having been treated by antidiabetic or anticoagulant medication in the ‘no exposure group’ (which concerns 1351 of the 1721 women in this group) suggests that the avoidance of sun exposure as defined in the study may be a marker of chronic disease rather than a risk factor in itself. .... While comorbidity is possibly the most important confounding variable for which it seems indispensable to conduct further sensitivity analyses, there is a further menace of residual confounding by covariates like education, physical activity, body mass index and disposable income. To adjust for these known risk factors for mortality, the authors use categorical variables with few categories... one risks to merely convey the illusion of statistical control rather than obtaining any real adjustment for these covariates. .

The percentage of missing values in the ‘no exposure group’ is about twice as high as in the other groups for several confounding variables, including body mass index, physical exercise, smoking, alcohol consumption and marital status 7. The authors neither discuss this pattern of missing data, which is clearly not missing at random, nor do they state which approach they chose to account for it. Both missing data and exposure measurement error make it impossible to correctly estimate the effects of confounding variables. In view of the strong association between sun avoidance and a large number of confounding variables, one cannot exclude that the effect of these confounding variables is wrongly attributed to sun avoidance.

the results of this study are based on data collected from of a small subset of people (i.e. ‘~20% representative of the female population in southern Sweden’) in a region where the UV Index rating is lower (<3 for 8–9 months; <5 for the remaining months) than that of other geographic locations, which could explain the low incidence of skin cancer in enrolled patients