In some of more alternative or holistic health circles, people have long said that most multi vitamin complexes are a waste because the body doesn't assimilate these forms of nutrition well at all. In fact, they are mildly not helpful because what the body cannot use, absorb or assimilate, it has to get rid of, and most people's bodies already have high waste product overload and so the elimination system and organs don't need any extra work in that area. (our poor livers, kidneys, etc)
I don't do it because i eat mostly vegetarian, but from a purely health perspective, a tip to boost nutritional absorption and assimilation when eating nutritionally dense foods like a spring mix salad, green drink, or the like. Put some gelatin in it.
Funny enough, a psychic named Edgar Cayce recommended this some 90 years back. It wasn't until the 60's that medical research started to discover that something like the above is actually a great, effective practice. Reason being, is that after the body has broken down the foods and extracted the nutrients, it tries to combine it most often with amino acids to pass through the gut into the blood stream. Amino acids are the ideal substance to make these "chelated" nutrients.
Gelatin is concentrated, relatively pure source of almost free form amino acids, it's a great booster supplement that makes the above process easier, faster and more efficient which ultimately leads to one absorbing and using more of the nutrition (especially minerals).