Sublingual B-12 is meant to be put under your tongue. With so many different types of vitamin B-12 supplements to choose from, it's important to understand which are best absorbed by your body. B-12 is a large molecule that relies on different factors in your stomach -- such as acidity and the production of intrinsic factor -- so oral forms of the vitamin are poorly absorbed. Sublingual B-12 tablets are often touted as being better absorbed and more effective, but research does not support this claim. Vitamin B-12 Vitamin B-12 is one of eight compounds that are collectively referred to as B-complex vitamins. B-12 is needed to make red blood cells, produce energy, synthesize DNA during cell division and to maintain normal cognitive function -- especially short-term memory and mood. B-12 from food and oral supplements is absorbed in the intestines with the help of intrinsic factor, a compound secreted in the stomach. Even with sufficient intrinsic factor and good intestinal health, B-12 is very poorly absorbed.
For example, about 10 micrograms of a 500-microgram oral supplement -- only 2 percent -- is typically absorbed in healthy people, according to the National Institutes of Health. Sublingual Supplements Sublingual supplements -- either as tablets or liquid drops -- are meant to be put under your tongue and absorbed through the mucosal membrane that lines your mouth. Substances absorbed under the tongue get into the bloodstream without having to go through the gastrointestinal tract. You’re not supposed to swallow while a B-12 tablet is dissolving under your tongue, otherwise the vitamin ends up in your stomach and defeats the purpose. Sublingual B-12 tablets usually come in 500- or 1,000-milligram doses. The amount of B-12 your body needs daily is only between 2.4 and 2.8 micrograms, but its poor absorption means you need to take more if supplementing. Absorbability The main advantage of taking sublingual B-12 is supposed to be enhanced absorbability -- at least greater than 2 percent -- and many companies selling the supplements claim this.
However, multiple studies have not supported this contention. A study published in a 2006 edition of the “Journal of Alternative and Complementary Medicine” concluded that there is no difference in efficacy between sublingual and oral B-complex supplements. Likewise, a study published in a 2003 edition of the “British Journal of Clinical Pharmacology” concluded that 500 micrograms of B-12 -- as cobalamin -- given either sublingually or orally is equally effective in correcting a B-12 deficiency. Supporters of sublingual B-12 supplements may claim that it’s absorbed faster than oral supplements -- and this seems logical -- but more research is needed to find out whether it’s true and what factors are involved. Intrinsic Factor and Acidity For B-12 to be absorbed in your intestines, intrinsic factor needs to be secreted by parietal cells in the stomach wall. The release of intrinsic factor is dependent on high acidity and the production of hydrochloric acid. People with deficient hydrochloric acid or intrinsic factor production may benefit the most from sublingual B-12 supplements because they may not be able to absorb any B-12 via the gastrointestinal route.
Affordability Another potential advantage of taking sublingual B-12 is affordability. Sublingual B-12 supplements are not appreciably different than oral supplements or intranasal sprays in terms of cost, but they are much less expensive compared to B-12 injections and intravenous B-12, which must be administered by a health professional. References National Institutes of Health: Office of Dietary Supplements: Vitamin B-12Journal of Alternative and Complimentary Medicine: A Single-center, Double-blinded, Randomized Controlled Study to Evaluate the Relative Efficacy of Sublingual and Oral Vitamin B-complex Administration in Reducing Total Serum Homocysteine LevelsBritish Journal of Clinical Pharmacology: Replacement Therapy for Vitamin B12 Deficiency - Comparison Between the Sublingual and Oral Route Photo Credits Stockbyte/Stockbyte/Getty Images Suggest a Correction Answer: Although sublingual B-12 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 sublingually found they were equally effective at correcting B-12 deficiency over a two-month period. It should also be noted that unlike the vitamin B-12 in foods, the purified form of B-12 found in supplements, including tablets, does not require stomach acid for absorption -- a potential concern for 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 for B-12 deficiency. in its B Vitamins Supplement Review). For more information about buying and using B-12 supplements, plus our tests of popular products, see the B Vitamins Supplements Review >> Also see these related CL Answers: I take omeprazole (Prilosec), a proton pump inhibitor, to reduce stomach acid. Are there supplements I should avoid, or be taking, due to this drug? How can I get more vitamin B-12 through my diet?
Are there any good vegetarian or vegan sources? Is it better to get vitamins from foods or supplements, and are natural vitamins better than synthetic vitamins? See other recent and popular questions >>We read all questions and try to answer those of popular interest.Vitamin B-12 is a water-soluble vitamin available through some foods or as a supplement. Your body needs sufficient vitamin B-12 levels to properly copy DNA, regulate neurological function and replicate red blood cells, according to the National Institute of Health's Office of Dietary Supplements. Adults need at least 2.4 micrograms daily. Sublingual B-12 is taken by placing a lozenge under the tongue. , sublingual vitamin B-12 has an advantage over other forms. claims sublingual vitamin B-12 is more rapidly absorbed and bio-available than B-12 tablets. The website states that the sublingual delivery route puts the vitamin directly into the bloodstream, bypassing the digestive system, where a lot of B-12 in tablets is lost.
A study published in the December 2003 issue of "British Journal of Clinical Pharmacology," however, determined 500 micrograms of sublingual or orally administered vitamin B-12 had similar success in raising B-12 levels among study participants. The researchers found no statistical difference in concentration between the two types, indicating there is probably no advantage in one form over the other. Does Sublingual B12 Really Work? How Fast Will B-12 Work? What Is Sublingual B12? Sublingual Vitamin B12 vs. Injectable B12 What Are the Effects of Vitamin B12 on Blood Pressure? How to Take Vitamin B-12 at Night Are There Side Effects of 2,500 Micrograms of Sublingual Vitamin B-12? What Is the Normal Intramuscular Dose of Vitamin B12? How Often Can You Inject B12? Symptoms of Low B12 Risks of Too Much Vitamin B12 Vitamin B-12 Deficiency & Bruising The Side Effects of B12 Lozenges The Best Time to Take Vitamin B-12 What Is the Difference Between an Injection of B12 and Taking It Under Your Tongue?