While B12 is naturally present in animal-based foods such as meat, fish, and dairy, many people struggle to get adequate amounts due to dietary restrictions, absorption issues, or certain medical conditions
Blood tests help confirm deficiency, monitor the effectiveness of injections, and prevent unnecessary overuse
It is not merely a piece of paper
Doses as high as 2 mg (2,000 g) daily by mouth or 1 mg monthly by intramuscular (IM) injection have been used to treat pernicious anemia without significant side effects (136)
Harvard Health Publishing
A highly concentrated solution can be difficult to measure accurately, and a small error in measurement can lead to a massive error in your experimental results