Standard dosing ranges from 0.25 mg to 0.5 mg daily via subcutaneous injection
Total Nutrient Intakes: Percent Reporting and Mean Amounts of Selected Vitamins and Minerals from Food and Beverages and Dietary Supplements, by Gender and Age, What We Eat in America, NHANES 2017-2018
You reconstitute these with 1mL, 2mL, or sometimes 3mL of bacteriostatic water depending on desired final concentration
In addition, the ability of your body to absorb vitamin B12 from food can be hindered by certain medications, such as metformin, proton pump inhibitors, and antacids
Comparable age groupings are proposed in the Dietary Guidelines for Americans, though the recommended intake levels differ, beginning at 0.5 g in infancy, increasing to 2.4 g for adults, and rising modestly during pregnancy and lactation (2.6 g and 2.8 g, respectively