b12 injections vs oral Vitamin vs. Supplements: Which Is Better? Frontiers | Efficacy of sublingual

N Z Med J 129 [PubMed] 16.Kotilea K, Quennery S, Decros V, Hermans DA (2014) Successful sublingual cobalamin treatment in a child with short-bowel syndrome

These are described as community-reported tolerability observations, not a controlled finding but they're consistent with how topical actives behave generally

Lysosomal acid lipase hydrolyzes retinyl ester and affects retinoid turnover

Studies show the consuming an excessive amount of vitamin B12 may: Increase the risk of cardiovascular events in people with diabetic nephropathy : A study published in JAMA sought to determine whether B vitamin therapy was able to slow the progression of diabetic nephropathy (kidney damage due to diabetes) and prevent vascular complications