Ingredient name: Magnesium
Chemical formula: Mg2+
Amount included in one pouch of Soylent: 414 mg (362 mg in vitamin blend in the form of magnesium oxide (MgO), and 52 mg of magnesium via the remainder of ingredients)
National Institute of Health Recommended Dietary Allowance: 400 to 420 mg daily for males 19 years and older. 310 to 320 mg daily for non-pregnant females 19 years and older.
Quantity in body: Approximately 24 grams. The majority (50 to 60 percent) of magnesium in the body is stored in bones. The remaining quantity of magnesium is found in soft tissue (non-organ and non-bone tissue). Less than 1 percent of the magnesium in the body is in the blood.
Nutrition role: Magnesium is a cofactor (an inorganic compound which activates an enzyme) in hundreds of enzymatic processes in the body. These processes are involved in muscle function, blood glucose control, Adenosine Triphosphate (ATP, a cell's primary source of energy) production and many others. In one such process, protein synthesis, magnesium plays essential roles in 3 of the 5 major stages of protein production. Magnesium's involvement in many metabolic pathways is largely related to its ability to neutralize anion (negative) charges in a compound.
Normally, only 30 to 50 percent of ingested magnesium is absorbed by the body. However, absorption rates can increase or decrease depending on the levels of magnesium already in the body. The Institute of Health's recommended dietary allowance takes into account the magnesium's absorption rates.
Absorption can be affected by the presence of other compounds. Phytic acid, a component of several types of dietary fiber, can decrease magnesium absorption because magnesium may bind to the acid's phosphate compounds, preventing them from being diffused through epithelial cells.
Reason this form chosen: MgO is a stable form of Mg2+ and has the most neutral flavor profile. Magnesium citrate was evaluated as well, but resulted in a strongly unpleasant flavor.
Production details: The magnesium oxide in the vitamin blend is produced by DSM Fortitech.
 Stipanuk, Martha H., and Marie A. Caudill. "Magnesium." In Biochemical, Physiological, and Molecular Aspects of Human Nutrition, 749. Third Edition ed. St. Louis: Elsevier, 2013.
 Nelson, David L., and Michael M. Cox. "Protein Metabolism." In Lehninger Principles of Biochemistry, 1115. 6th ed. New York: W.H. Freeman, 2013.
 Stipanuk, Martha H., and Marie A. Caudill. "Magnesium." In Biochemical, Physiological, and Molecular Aspects of Human Nutrition, 747. Third Edition ed. St. Louis: Elsevier, 2013.
 Ibid, 748.