Frontiers Efficacy of sublingual and oral vitamin B12 versus intramuscular administration: insights from a systematic review and meta analysis Oral vs. Intramuscular Vitamin B12 in Vitamin B12 Deficiency The Blood Project Vitamin B12 is essential for energy production, nervous system function, and red blood cell formation. However, oral B12 supplementation doesn't work well for everyoneabsorption can be limited by digestive issues, certain medications, Vitamin B12 Benefits and Best Sources Vitamin B12 Injections vs. Oral Supplements: Which is Better? Uniq Laser What are vitamin injections? Vitamin injections deliver essential nutrients directly into the body, meaning faster absorption compared to oral supplements Popular options include: B12 for energy Vitamin C