These include vitamin B12 deficiency and malabsorption that is caused by the following medical conditions, according to the NIH [1]: Pernicious anemia Tropical sprue Pancreatic insufficiency Surgery in the gastrointestinal tract Certain medications Deficiency in the diet Side effects of B-12 injections Also, according to the NIH, vitamin B-12 injections have some potential side effects, including [1]: Diarrhea Itching Swelling Risk of allergic reaction and anaphylaxis Can Vitamins Aid in Weight Loss

(2000), Horm Res 53(Suppl 3), PubMed 10971106 Statistics from preclinical literature AOD-9604 = modified fragment of hGH 177191 + N-terminal Tyr (sequence Tyr-Leu-Arg-Ile-Val-Gln-Cys-Arg-Ser-Val-Glu-Gly-Ser-Cys-Gly-Phe), molecular weight 1815.1 Da Developed at Metabolic Pharmaceuticals (Australia) based on the work of professor Frank Ng (Monash University) in the 1990s Standard experimental dose in obesity clinical trials: 1 mg/day subcutaneously (Phase 2b, Heffernan et al.) Mechanism: stimulation of 3-adrenergic receptors in adipose tissue, increased lipolysis and fatty acid oxidation without activation of the hGH receptor (no IGF-1 increase) Phase 2b clinical trial (2007, 300 patients): weight reduction ~2.8 kg vs placebo over 12 weeks FDA status: NDI rejection (2014) as a dietary supplement
Pregnant women with B12 deficiency are at a higher risk of giving birth to babies with neural tube defects or other developmental issues
Your body uses vitamin B12 more efficiently when you consume folate (vitamin B9) and iron together