The primary advantage of B12 injections over supplements is the direct delivery of the nutrient to your bloodstream, as opposed to passing through your digestive tract
Therefore, there is a very low risk of B12 toxicity, even at high doses like 1,000 mcg a day
So for glucose alone, more milligrams buy little
In such cases, we are committed to restoring service as quickly as possible, but immediate restoration is not always realistic
How bioavailable or in other words, how absorbable a vitamin is is often influenced by factors, like age, genetics, and a persons digestive system ( For example, people with conditions affecting the digestive system might not benefit from liquid, gummy, or pill forms of vitamin B12
PMID: 31735792 5 Megaloblastic Anemias: Nutritional and Other Causes