Serious caution note about the use of B12 (sublingual) tablets, sprays and patches

About oral supplementation:

We see a big problem whenever oral B12 supplementation is discussed and in this way we would like to make a contribution with information for our foreign website visitors:

Important note: we do not sell vitamins, vit B12 injections, ampoules, (sublingual) tablets, nor do external parties, companies and such financially support us.

We want to alert you to the following:

Although the NHG[1] and some other scientists accepts that oral supplementation has been proven, we see in clinical practice that oral supplementation is inferior compared to injections and we also think their efficacy has not been scientifically established. The reason: almost all research is not, or hardly, linked to the symptoms, but only to the raising of B12 blood serum values. And this is precisely which is meaningless after supplementation, which is also acknowledged by the NHG: “We do not see that testing the B12 serum level after receiving supplementation as useful”. Research and literature that warns us of the more limited effect of tablets, is pushed aside and ignored[2]. The efficacy of tablets is also NOT scientifically validated. We think this is an important problem and we see the consequences directly in our clinical practice. See also our response[3] to the NHG protocol[4].

The B12 Research Group NL has currently seen more than 2000 vit B12 def patients and we are in direct contact with thousands of others through patient forums. Contrary to what is read, only some patients are helped by (sublingual) tablets, but not everyone. This is our experience, especially in the long term and with serious symptoms (especially neuropsychiatric). Tablets may be used as additional supplementation (if you have a long wait between injections and if your initial blood levels have been determined). The problem is that a few “success stories” are promoted as a treatment that works, while the stories are only isolated personal experiences. We think this is very unfortunate as we experience exactly the opposite.

Research shows, and that is also our clinical experience, that hydroxocobalamin i.m. (or deep s.c.) injections are the most proven superior treatment in B12 deficiency, certainly with neurological and psychological symptoms. Hydroxocobalamin facilitates both pathways (conversion to methylcobalamin and adenosylcobalamin) and it works in a more natural way. There are pathways in the complex metabolism/conversion to active forms that we (& the clinical chemists who we work with) do not know yet and which we therefore deliberately do not want to skip.

The comment “it skips the conversion process and helps directly in the active form” we think of as an unscientific approach – to put it mildly. In addition, hydroxocobalamin is an anti-dote of (cyanide) toxins, which is partly due to its complex molecular structure.

If you get the comment: “In Sweden they have been working with high dosage tablets for years, with great satisfaction”, you can reply as follows:

The B12 Research Group has direct personal contacts with Swedish specialists and researchers, and from them we learn that they, together with psychiatrists and neurologists purposely do not work with tablets when obvious (neurologic and/or psychiatric) symptoms of B12 deficiency are present. They know better from their clinical practice. There has never been a proper investigation in Sweden about the efficacy of tablets, nor has there been an investigation that patients are “satisfied with their oral treatment”.

So do not be convinced by the few positive personal stories that you hear. Ok for that person, Ok for you perhaps, but in our hospital we NEVER take the risk of insufficient commitment to treatment. We believe your recovery is far too important. Recovering from a B12 deficiency is difficult enough already.

The stories about problems with methylation are also heavily exaggerated by tablet sellers and the so-called figures on this (90% or 80% cannot methylate) are incorrect. Rather, it is vice versa: perhaps about 5 to 10% of the patients have reduced methylation. We experience this as a sales trick (sublingual tablets) and see people who have been even injecting methylcobalamin sometimes respond better to and become stronger with hydroxocobalamin. Often more frequent hydroxocobalamin is a good solution, as is the case in very serious metabolism disorders. In a few cases we try methylcobalamin. In the methylation process, other co-factors (like folate) are very important too. There could also be other underlying factors causing remaining symptoms such as: thyroid problems, Lyme disease, copper deficiency and an excess of B6 supplementation.

Recovery from a B12 deficiency with substantial symptoms unfortunately requires time and patience and also has ups and downs.  It is very important for you and your physician, to monitor your symptoms properly[5].

© Clara Plattel | B12 Research Group NL, Rotterdam dec 2015

[1] NHG = Nederlands Huisartsen Genootschap -> Dutch College of General Practitioners

[2] (Chevalier, 2007; A. Freeman, Wilson, Foulds, & Phillips, 1978; A. G. Freeman, 1999; Hunt, Harrington, & Robinson, 2014; Kaplan, Mamer, & Hoffer, 2001; Regland et al., 2015; Rundles, 1946; L. R. Solomon, 2006; L. R. R. Solomon, 2004) (British Society for Haematology, 2014; Carmel, 2008; Schrier, 2014)


[4] Dutch GP protocol:

[5] (Carmel, 2008)


British Society for Haematology, T. (2014). Guidelines for the diagnosis and treatment of Cobalamin and Folate disorders. The British Committee for Standards in Haematology (BCSH)

Carmel, R. (2008). How I treat cobalamin (vitamin B12) deficiency. Blood, 112(6), 2214-2221. Retrieved from

Chevalier, P. (2007). Vitamine B12 oraal of intramusculair toedienen? Minerva, Tijdschrift voor Evidence-Based Medicine, 6(2), 2.

Freeman, A., Wilson, J., Foulds, W., & Phillips, C. (1978). Why has cyanocobalamin not been withdrawn? Lancet, 1, 777 – 778.

Freeman, A. G. (1999). Oral or parenteral therapy for vitamin B12 deficiency. The Lancet, 353(9150), 410-411. doi:

Hunt, A., Harrington, D., & Robinson, S. (2014). Vitamin B12 deficiency, Clinical review. 349. doi:10.1136/bmj.g5226

Kaplan, L. N., Mamer, O. A., & Hoffer, L. J. (2001). Parental vitamin B[sub12] reduces hyperhomocysteinemia in end-stage renal disease. Clinical & Investigative Medicine, 24(1), 5. Retrieved from

Regland, B., Forsmark, S., Halaouate, L., Matousek, M., Peilot, B., Zachrisson, O., & Gottfries, C.-G. (2015). Response to Vitamin B12 and Folic Acid in Myalgic Encephalomyelitis and Fibromyalgia. PLoS ONE, 10(4), e0124648. doi:10.1371/journal.pone.0124648

Rundles, R. W. (1946). PROGNOSIS IN THE NEUROLOGIC MANIFESTATIONS OF PERNICIOUS ANEMIA. Blood, 1(3), 209-219. Retrieved from

Schrier, S. L. (2014, 2014). Up To Date: Diagnosis and treatment of vitamin B12 and folate deficiency.   Retrieved from

Solomon, L. R. (2006). Oral pharmacologic doses of cobalamin may not be as effective as parenteral cobalamin therapy in reversing hyperhomocystinemia and methylmalonic acidemia in apparently normal subjects. (0141-9854 (Print)).

Solomon, L. R. R. (2004). Oral vitamin B12 therapy: a cautionary note. Blood, 103(7), 2863-2863.


We increasingly see (commercial) web sites appear by non-medical people, who use our name, personal names, texts and data to promote their own services and especially their products (sublingual) tablets as the solution to your problems. Some sites/people suggest that we work together and/or support these people. This is doubly annoying because it generates the impression that we also support their way of working and their treatments. This is absolutely NOT the case.

Even worse: their treatment methods often endanger the treatment of B12 deficient patients. These patients eventually present themselves at our polyclinic (there is a waiting list) with many symptoms because the general practitioner will not help them with such (false) high B12 values caused by the tablets.

You will often read about the success stories only; the failed cases will not be accepted or acknowledged.