injection de b12 Methylcobalamin (Vitamin B12) File:Hydroxocobalamin Injection.jpg - Wikimedia Commons

People who eat a vegetarian diet, especially strict vegans, need to take extra vitamin B12

Maternal Vitamin B12 Status During Pregnancy and Its Association With Outcomes of Pregnancy and Health of the Offspring: A Systematic Review and Implications for Policy in India

Supports Optimal Vision We are used to our vision deteriorating as we get older and Vitamin B12 deficiency is associated with macular degeneration and glaucoma, this is because of its effect on the nervous system and also homocysteine levels (have you had your homocysteine checked?) Enhances Cardiovascular Health High homocysteine is linked to an increased risk of cardiovascular disease, and B12 along with folate are important nutrients to maintain healthy homocysteine levels

This stacking approach lacks formal study but has theoretical basis