Vitamin B Supplementation: Oral Capsules vs. Sublingual Tablets AZ Dietitians Should You Take Natural vs. Synthetic B12? B12 Complex Methylated Vitamin 1000mcg, Sublingual, Clean Igennus Igennus Healthcare Nutrition Amazon.com: Organic Vitamin B12 1000 mcg Sublingual Liquid Drops For Adults, 6 Months Supply 1 oz, Methylcobalamin & Adenosylcobalamin Bioactive Blend for Energy, Clarity & Focus Vegan, Non GMO, Unflavored : Health & Household Efficacy of different routes of vitamin B12 supplementation for the treatment of patients with vitamin B12 deficiency: A systematic review and network meta analysis Irish Journal of Medical Science (1971 )