Is sublingual vitamin B-12, which is placed under the tongue and allowed to dissolve, really better than the pill form?

Answer:

Although sublingual B-12 — a form placed under the tongue and allowed to dissolve — is often promoted for better absorption, there does not appear to be much evidence for this. In fact, one clinical study comparing the same amount of B-12 given orally or under the tongue found they were equally effective at correcting B-12 deficiency over a two-month period.

Be aware that sublingual B-12 supplements often contain sugar substitutes such as sorbitol, mannitol or sucralose, which can cause gastrointestinal symptoms in some people.

It should also be noted that unlike the vitamin B-12 in foods, the purified form of B-12 found in supplements, including regular and sublingual tablets, does not require stomach acid for it to be made available for absorption. This benefits people with low stomach acid (including many people over the age of 50) or those who take acid blockers such as Pepcid or Zantac, or proton pump inhibitors such as Prevacid, or Prilosec, who are at an increased risk for B-12 deficiency. For those who have difficulty with large pills, keep in mind that only a very small amount of B-12 is required to meet the recommended daily intake and can be obtained in small tablets, including those tested by ConsumerLab.com in its B Vitamins Supplements Review, which includes our Top Pick for vitamin B-12 and the latest information about B-12 dosage and safety and when to take vitamin B-12.