I don't think the gulf is as significant as you're making it sound based on "30 seconds of googling". I had a pretty severe vitamin D deficiency a year or two ago and the (high-IU) prescription my doctor wrote for me was D2. I asked him if I could just buy OTC D3 pills and take more of them, and his response was "yea that's fine, if anything those are more bio-available".

This medical professional's nonchalance about the difference is in pretty stark contradiction to your bizarre claim that they "aren't doing even shallow research into nutrition". There's a million possible reasons they may have decided not to optimize solely for bio-availablility, just as my doctor did.

I don't think it's a bizarre claim at all. The ingredients just don't look like the recommendations of nutritionists, dieticians, or researchers focusing on nutrition. Nothing aiming at human health would have soy protein (59% bioavailability) and maltodextrin (absorbed by your body as fast as glucose but doesn't need to be listed as a sugar) as the first two ingredients. Why oh why are these two of the most common ingredient all over the bar and shake industry? Could it be because they are dirt cheap?

I was responding specifically to the vitamin D claim, since that was the evidence you presented to make your fairly-extreme claim (and one that I happened to have some personal knowledge about).

Even in general though, I don't see why the only thing to optimize for is as much bioavailability as possible. People care about things like cost too. (Though this opinion of mine is a lot less strong than my reaction to your initial claim)

I skimmed the paper you linked to and if I understood it correctly D2 has lower bioavailability than D3.

Is that the primary difference?

That's one important takeaway. But we don't actually know what (synthetic) D2 and (food derived) D3 are doing differently in the body. This is exacerbated by: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4210929/

That there's this much nuance just with this one ingredient is a microcosm of the overall flaw in Soylent's approach.

Optimizing for just the legible dimensions of a poorly understood domain will not result in good outcomes.

For mealsquares we take consilience seriously and combine the inside and outside view (see: reference class forecasting) on human nutrition to try to establish reasonable confidence intervals around nutrition models, and even then we aren't stupid enough to think or claim that mealsquares are just as good as fish, fruit, and vegetables.

>> Optimizing for just the legible dimensions of a poorly understood domain will not result in good outcomes.

Thank you. This one sentence can replace all my responses to the original post.

Wow, the NIH paper now has me asking if this might also be a public health problem.