Vitamin B12 aids with protein metabolism, red blood cell production, and promotes the healthy function of the central nervous system. B12 is absorbed in the small intestine, therefor certain health conditions and medications can prevent your body from absorbing this vitamin. Those who follow a plant-based or vegetarian diet may not be getting a sufficient amount in their regular diets as vitamin B12 is found in animal products. It is stored in the liver and may take a while to become depleted. Those deficient in B12 can suffer from symptoms including: fatigue, constipation, loss of appetite, or irritability.
Cyanocobalamin – 1000mcg/1mL – $25
Cyanocobalamin is a synthetic form of B12 that the body converts into Adenosylcobalamin and Methylcobalamin before it is used. It’s the most common form of B12 found in injections, and is often found in some supplements and fortified foods, though that route is less effective for absorption than in intramuscular injection.
Hydroxocobalamin – 1000mcg/1mL – $40
Hydroxocobalamin is another form of B12 that is highly bioavailable, and is used to treat those with a serious deficiency. It tends to be stored by the body for a longer period of time, allowing for larger gaps between doses. It’s only available as an intramuscular injection.