Strictly speaking, choline is not a vitamin, but a vitamin-like compound. This means that it is similar in activity to a vitamin, but is capable of being synthesized by the body
J Nutr Sci Vitaminol (Tokyo) (2018) 64:3218
Glutathione is made out of amino acids, so the main dietary influence over your glutathione levels will be your intake of protein
Any human dosing advice or medical claims, which the FTCs health-claims guidance treats as a warning sign
Abbott AE Jr, Hill RC, Flynn MA, McClure S, Murray GF
Dosage Protocols: Research Evidence and Clinical Observations Dose-response research on melanocortin peptides establishes a therapeutic window rather than a single optimal dose