Ingredient name: dl-Alpha-Tocopheryl Acetate (Vitamin E)
Chemical Formula: C31H52O3
Quantity in one pouch of Soylent: 30 IUs
Institute of Medicine daily recommended intake: 22.4 IUs
Vitamin E is one of the most effective lipid-soluble antioxidants. The body needs antioxidants to prevent a variety of compounds from undergoing undesired oxidations, which - if left unchecked - can cause significant damage to tissue and cells.
Vitamin E stops lipid peroxidation, which is caused when an unpaired electron (also known as a free radical) starts a chain reaction that can break apart and damage a cell's phospholipid membrane. Vitamin E functions by reacting with the electron (and the oxygen- or nitrogen-based molecule that the "free" electron is associated with) which prevents the destructive chain reaction from taking place in the cell membrane. Some data shows that vitamin E reacts with certain type of free radicals 1,000 times faster than the free radicals would be able to react with polyunsaturated fatty acids (a type of lipid).
Unchecked lipid peroxidation has been linked to atherosclerosis, and inflammation. An adequate supply of vitamin E provides cell membranes throughout the body with a defense mechanism for oxidative reactions.
Vitamin E is extremely hydrophobic (insoluble in water) and as such, its absorption mechanism is similar in many ways to other lipids. Some studies suggest that up to 70 percent of ingested vitamin E is absorbed in the small intestine, while others suggest only 50 percent of all consumed vitamin E is absorbed before being excreted.
After absorption in the small intestine, vitamin E, along with other lipids, is transferred to the liver via intercellular space and the lymphatic system.
There are four different types of tocopherols. Of these, alpha-tocopherol is the biologically active version and is highly favored by the alpha-tocopherol transport protein for secretion from the liver into the bloodstream, where it is bound to several types of cholesterol-carrying proteins and transported throughout the body. The vast quantity of the remaining three types of tocopherols (beta-, delta- and gamma-tocopherol) are metabolized in the liver and excreted from the body.
Reason this form chosen
Dl-alpha-tocopheryl acetate is the synthetic form of alpha-tocopherol. While this form has a slightly decreased bioavailability from alpha-tocopherol, this can be overcome by an increase in quantity. Please note that the IUs are compound-specific and account for the reduced bioavailability of the synthetic form of vitamin E.
 Ibid., 251-252.
 Buettner, G.R. "The Pecking Order of Free Radicals and Antioxidants: Lipid Peroxidation, α-Tocopherol, and Ascorbate." Archives of Biochemistry and Biophysics 300, no. 2 (1993): 535-43. http://plk.tn/1bPM0Dh
 Manor, D., and S. Morley. "The Alpha-tocopherol Transfer Protein." Vitamins & Hormones 76 (2007): 51. DOI: 10.1016/S0083-6729(07)76003-X
 Kayden, Herbert J., and Maret G. Traber. "Absorption, Lipoprotein Transport, and Regulation of Plasma Concentrations of Vitamin E in Humans." Journal of Lipid Research 34 (1993): 344. http://plk.tn/1C9xICm
 Stipanuk, Martha H., and Marie A. Caudill. "Vitamin E." In Biochemical, Physiological, and Molecular Aspects of Human Nutrition, 671. Third Edition ed. St. Louis: Elsevier, 2013.
 Absorption rates are taken into account when Daily Recommended Intake levels are calculated.
 Ibid., 671-672.