If you have known MTHFR mutations, a history of poor response to cyanocobalamin, or strong preference for methylcobalamin, seeking a formulation with that form is reasonable
The vitamin B complex injection contains a combination of B-group vitamins including thiamine (B1), riboflavin (B2 as riboflavin-5-phosphate), nicotinamide (B3), dexpanthenol (pro-vitamin B5), and pyridoxine (B6)
Vitamin B6 (Pyridoxal Phosphate) Food sources: Poultry, fish, and organ meats
[142] Identification of liver as an anti-anemia food [edit] During the 1920s, George Whipple discovered that ingesting large amounts of raw liver seemed to most rapidly cure the anemia of blood loss in dogs, and hypothesized that eating liver might treat pernicious anemia