Uses of Vitamin B12 - Improves the formation of red blood cells and prevents anemia - Prevents neural tube defects - Improves bone health and prevents osteoporosis - Prevents macular degeneration - Boosts mood and prevents anxiety - Improves brain functioning - Gives sense of being healthy - Enhances heart health - Improves health of skin, hair and nails There are no severe side effects of Vitamin B12. Interactions of Vitamin B12 - Antibiotics - Anti-seizure drugs - Metformin - Proton antagonists Dosage of Vitamin B12 - For adults over age 50 = 1 g - For adults under age 50 = 2.4 mcg - Pregnant women = 2.6 mcg - Breastfeeding women = 2.8 mcg