Vitamin B12, which most humans get from meat, seafood, and dairy products, is essential for red blood cell production and DNA synthesis
10.1016/s1535-6108(04)00059-5 30 KanayamaG.HudsonJ
Its naturally available from animal products, including fish, meat, poultry, eggs, milk, and milk products but its not usually present in plant foods
While having megaloblastic anemia, hyperhomocysteinemia, and/or neuropathy are not medical conditions that influence vitamin B12 absorption, they are clearly indications for the use of vitamin B12 supplements when deficiency is established
However, if the research demands medical oversight for administration, injectables might be feasible