It seems like the barriers to innovation are insurmountable to everyone with the will to try
Why?
When it comes to running studies, you could run a study for the effect of taking Vitamin D in the morning vs. in the evening. Various QS people have found an effect for themselves. The effect should be there. As far as I know there no study establishing the effect. Doesn't seem to be difficult for someone without resources but with a decent amount of time on their hand.
As far as diagnostic tools go, we today have a lot of smart scales and blood pressure measurement devices. As far as I know nobody produced a similarly smart peak flow meter (/ FEV1). Such a device would allow the gathering of more data for a lot of people. More and better data means more opportunities for scientific insight.
On a more theoretical level I think there could be advances in organizing the large pile of biological and medical knowledge we have. I don't think that textbooks and journal articles are good mediums for transferring knowledge between scientists. Protein databases like uniprot contain a lot of information in a way that's easy to query. I think that finding ways to organize less structured biological insights and the evidence for them is an area with a high potential impact.
This thread is for asking any questions that might seem obvious, tangential, silly or what-have-you. Don't be shy, everyone has holes in their knowledge, though the fewer and the smaller we can make them, the better.
Please be respectful of other people's admitting ignorance and don't mock them for it, as they're doing a noble thing.
To any future monthly posters of SQ threads, please remember to add the "stupid_questions" tag.