>In fairness to researchers, it can be difficult to run a randomized clinical trial for vitamin D supplements. That’s because most of us get the bulk of our vitamin D from sunlight
And how hard is it to make such controlled studies on prison populations (where both sun and food intake is also a known value)? Make it voluntary and give some incentives for those wanting to participate. Can study supplement effects for one or even five years, it's not like they're going anywhere.
That's also a question I have when I hear about diet studies. What's easier than doing such in prison populations? Make it as voluntary as it's for people outside, and there's no ethical issue. We're talking like checking the effect of this or that food or diet style, which they can let different people chose their own. They already eat what they're given anyway, that would be an improvement.
> And how hard is it to make such controlled studies on prison populations (where both sun and food intake is also a known value)?
Very hard. Not impossible, but even something as low risk as a dietary study with Vitamin D supplements would come under very heavy scrutiny and likely be rejected.
Prisoners are considered a vulnerable group with diminished autonomy so there is no such thing as “voluntary as it's for people outside“ in prison. Full stop. The Nuremberg Code, Belmont Report, and Declaration of Helsinki all explicitly spell that out.
Even ignoring the obvious “ethical issues” that have been settled since the Nazis, they’re also legally protected. See 45 CFR 46 Subpart C [1]. Even if the experiment got past the academic ERBs, the HHS ones will likely shut it down.
[1] https://www.hhs.gov/ohrp/regulations-and-policy/regulations/...