Jackmannii, I would however take the position that the packaging of real foods that we evolved eating is likely to be superior. (“Likely” as a default, but not necessarily.) This is not thinking that nature is designed to benefit us, but that we evolved to thrive within the real world eating real foods (i.e. we are the puddle that formed a shape to fit the hole, not the other way around).
dzero, I think we can agree on your last post and I perhaps reacted a bit strongly. Vitamin D deficiency right now is the trendy thing in medicine. That it is involved with much more than had been previously understood is pretty solidly established, but what should be the level to label someone as deficient, what role diet and/or supplements and what role moderate sun exposure should play, and whether or not supplementation has an impact on a wide variety of conditions, are all very much works in progress, and subjects of very active debate. Many are very wary, having lived through hype with A, C, and E, only to find that supplements were more likely causing harm than good.
Maastrricht, please note that your first cite confirms my point that a doctor even having someone consider B12 shots is a reason to suspect you may be dealing with a quack. Basically the role of B12 shots was historically for pernicious anemia, an autoimmune disorder which leads to poor absorbtion of B12 and shots may still used initially for that I believe. About one in 7,500 get pernicious anemia and most of those people are over 60. So while I admit as a pediatrician I don’t see any of them, I’d still call one in 7,500 rare enough to be rare. Other than that one condition B12 shots are given, generally, by quacks.
For some reason your other links are not working for me. But I accept your statement of what they say. And? 5-10% do not get RDA. Probably worse for D and E and a few others. Many eat lots of crap and not enough real food. How often does that lack of recommended target intake cause problems and does how does that inform on the question of the superiority of getting vitamins from real foods in a varied diet?
I’ll also refer to this WebMD review. Yes, specific conditions (like pernicious anemia, celiac, inflammatory bowel diseases, or bariatric surgery) and lack of dietary sources can result in B12 deficiency. The rest (the vast vast majority) of us “get more than enough B12 from eating meat, eggs, milk, and cheese.”