Everything we see right now is mere speculation
This is helpful because it bypasses your digestive system, where B12 absorption often breaks down due to gut health issues or low stomach acid
If you follow a vegetarian or vegan diet, then you can change your diet to include B12-fortified grains, a supplement, a high-dose oral vitamin or B12 injections
These include sarcoidosis, high phosphate blood levels, high calcium blood levels, excessive vitamin D levels, arteriosclerosis with occlusion of the arteries, kidney stones, kidney disease with reduced kidney function, and allergies to vitamin D
That matters when you are working with compounds that cost significant money per vial and where dosing precision determines whether your research succeeds or fails
Many also mention better focus and steadier mood