This post is more of a reply to soylent.ca's sales and the fact that the recipe the girl from popsci was using was made by a biochemistry student not a nutrition store snake oil sales man or a copycat DIY
people should be extremely careful with all of these DIY formulas. someone becoming ill from an overdose due to miss labeling from the manufacturer or personal error in measurements seems like something that is just waiting to happen. Also this DIY being done by people with no experience in the medical field and lack of knowledge in general chemistry, biology and laboratory topics is dangerous.
If anyone is really committed to their own health and wants to undertake an endeavor such as this one, i would highly recommend reading some basic books.
I would recommend any chemistry book that covers nomenclature, basic units of measurements, conversions and stoichiometry.
This is a textbook i have come across, its cheap and has a fair bit of information. It is written in a way that someone with no experience in chemistry is able to understand. The mathematics used in it is limited to pre calculus although the extent required for the concepts above is very basic algebra.
Along with that, i would highly recommend that people read and understand the implications of material safety data sheets.
Manufacturing tolerances and 3rd party testing results of manufacturing standards is something worth looking into for all suppliers.
Rob recommended these biochemistry book,
I like this textbook
http://www.amazon.com/Lehninger-Principles-Biochemistry-David-Nelson/dp/1429222638 -- from my first class solely on biochemistry,