Taking Sublingual Vitamin B12
In addition to the traditional route of absorption through the mucosa of the intestine, vitamin B12 can also be absorbed through the oral mucosa. This has a theoretical advantage, if absorption via digestion is impaired, as it allows the B12 to bypass the route through the intestine.
Just how much vitamin B12 can be absorbed through the oral mucosa and how much is simply swallowed down into the intestine regardless has not been explored to date. However, it is a certainty that sublingual absorption is at least as effective as normal oral absorption.1
Sublingual Vitamin B12: Lozenges, Drops and Sprays
There is a variety of vitamin B12 supplements which use sublingual absorption:
- Vitamin B12 lozenges
- Vitamin B12 drops and sprays
- Vitamin B12 strips
- Vitamin B12 toothpaste
Drops and sprays are administered directly under the tongue, whereas strips and lozenges dissolve slowly under the tongue. These forms of vitamin B12 supplements are particularly good for children and adults who have problems with swallowing tablets and capsules, as they represent the most comfortable solution.
Advantages of Sublingual Vitamin B12 Supplements
The different supplements which are suitable for sublingual B12 absorption have the following advantages:
- Absorption in the mouth
- Critical intake in the intestine can be avoided to an extent
- Easy to handle, manage and use
Active Ingredients in Sublingual Vitamin B12 Supplements
There is a range of active ingredients used in sublingual B12 supplements to choose from. Here is a short overview of these:
Natural B12 Form?
Bioactive / directly usable?
no, artificial form
No, 4 steps to conversion
Produces a small amount of cyanide, therefore not suitable for smokers or for detoxification. General effectiveness is proven, but worst absorption and long-term effect
Very good absorption and effectiveness for all purposes
No, 3 steps to conversion
Common form of B12 in foods, good sustained release effect
Dosages of Sublingual Vitamin B12
The exact B12 intake capacity of the oral mucosa is unknown, but it is expected to roughly equal the passive diffusion in the intestine. This equates to 1-2% of the full dose. In addition, a maximum of 1.5 µg of the vitamin B12 is eventually absorbed through the help of the intrinsic factor via swallowing.
In order to be certain of covering the RDA, sublingual supplements should thus contain around 300-500 µg of vitamin B12.
Disadvantages of Sublingual B12 Supplements
Many sublingual products contain additives, like flavourings and colourings, which are obviously not always desired by health-conscious people. An overview of the current additives with occur in various B12 supplement forms can be found in the following specific articles:
As a general rule, strips and lozenges contain the most additives, whilst drops and sprays tend to have less. Readers who want to use the more comfortable methods of absorption, but would prefer to avoid the additives, are therefore best advised to use drops or sprays.
Vitamin B12 Toothpaste
A very new form of sublingual supplements is the vitamin B12 toothpaste. The best known product of the firm Sante contains around 3 µg of cyanocobalamin when used twice daily, and is therefore suitable for as a vitamin B12 supplement. A study conducted by the German institute for alternative and sustainable diet (IFANE) in Giessen found that a significant improvement in vitamin B12 markers and thus a good effectiveness of the toothpaste could be clearly seen after five weeks of use.2 At the expressed interest of customers, a fluoride-free product is now also available.
1Sharabi, A., Cohen, E., Sulkes, J. and Garty, M. (2003), Replacement therapy for vitamin B12 deficiency: comparison between the sublingual and oral route. British Journal of Clinical Pharmacology, 56: 635–638. doi: 10.1046/j.1365-2125.2003.01907.x