The bioefficacy of an oral glutathione supplement formulation is determined by its bioavailability and absorption of the active ingredient in the body
10.1007/s12031-018-1091-5 72
L-carnitine forms the transport system that moves fatty acid molecules into the mitochondria (furnaces) of the cell where they are burned for fuel (Strack, et al 1964)
"[205] Preparation of the reduced forms of vitamin B12 and of some analogs of the vitamin B12 coenzyme containing a cobalt-carbon bond", Vitamins and Coenzymes , Methods in Enzymology, vol
Vitamin D has strong immunomodulatory properties
according to the National Academies of Sciences, Engineering, and Medicine, absorption is approximately 50% at 1 mcg but falls to roughly 1.3% at 1,000 mcg