Vitamin B6 and B12 Supplements Appear to Cause Cancer in Men

Using more than 55 micrograms (μg) of B12 daily appeared to quadruple cancer risk.

Lung-cancer risk among men who took 20 milligrams (mg) of B6 daily for years was twice that of men who didn’t.

A product like a high-dose B6 and B12 supplement hits shelves, and only decades later do researchers begin to understand the long-term health effects, who might benefit from taking it, and who might be harmed.

1 gram is equal to 1000 milligrams (mg).

1 mg is equal to 1000 micrograms (aka μg or else mcg)


*centrium* per tablet in USA link
-Vitamin B6 6 mg
-Vitamin B12 (as cyanocobalamin) 100 mcg

*centrium* per tablet in EU declaration ‘Contains Toxic Chemicals’
-Vitamin B6 2.1 mg
-Vitamin B12 (as cyanocobalamin) 3 mcg

*swisse* per tablet link
-Vitamin B6 (from pyridoxine hydrochloride) 24.68 mg
-Vitamin B12 (as cyanocobalamin) 30 mcg



Centrium – different US and EU ingredients

This is the link to the homepage of Pfizer in the US and shows the formula for the US product. The formulas of Centrum in the US and in Europe are different due to differences in the respective food laws in the US and in Europe. In the US formula you will find for example ingredients like Tin, and Vanadium which are not allowed according to European food law. There are also distinct differences in the labelling of the products. Due to these differences in the composition and the labelling it is not allowed to sell the US product in Europe. Our formulas in Czech and the other European countries are produced in Europe and are of course also in compliance with the European food law. They also contain only a low amount of B12 per tablet and are as well labelled according to European food law.


As you can understand, I mailed the companies, the Swisse reply :

We would like to inform you that every ingredient must meet stringent quality parameters as well as comply with the regulations set by the Therapeutic Goods Administration of Australia. If you are concerned about the use of these vitamins, we recommend that you consult your Primary Healthcare Professional.


As you can understand, I mailed the companies, the Centrium reply :

B vitamins in focus

A recent study, published in the Journal of Clinical Oncology, is investigating the long-term use of B vitamins B6 and B12. The study found, after the observation of approximately 77,000 participants, that the long-term intake of B vitamins B6 and B12 should greatly increase the lung cancer risk in men, especially smokers.(1)

In order to be able to determine the relevance of the results, individual points must be considered carefully. Furthermore, further investigations and recommendations of renowned authorities should be consulted for the final assessment.

Researchers of the observational study asked study participants aged 50-70 to recall information from the past ten years. This is certainly a major criticism of this study because it is likely to be difficult for most participants to remember exactly what they did over a period of 10 years. The study participants were specifically asked about the intake of B vitamins vitamin B6, folic acid and vitamin B12. Besides vitamin intake, other parameters such as body weight, nutritional behaviour, tobacco consumption, education, family history and other parameters were also considered. The average dose over this period was used as an essential parameter for the evaluation.

According to the results of the survey, the groups of people in the study clearly exceeded the intake recommendations for vitamins. The multivitamin preparations such as Centrum and also folic acid preparations showed no influence on the risk of lung cancer if taken permanently. The increased intake of vitamin B6 (more than 20 mg / day, which is about 10 times more than in Centrum) and vitamin B12 (more than 55 μg / day, which is about 20 times more than in Centrum) over a period of ten years led to an increased lung cancer risk only in men, predominantly smokers. For women of this cohort, however, no increased risk was detected. These differences could not be explained by the authors of the study.

In this respect, conclusions from these results should be interpreted very carefully: this study was conducted on smokers. It is known that cigarette smoking can cause cancer. A conclusion that vitamin B6 and vitamin B12 intake is the cause of the increased risk of lung cancer in smokers therefore cannot be conclusively concluded scientifically.

Observational studies such as these can thus prove no causal relationship between the intake of B vitamins and the occurrence of cancer. These results remain hypothesis, since only a statistical correlation could be shown.

In comparable studies so far no comparable effect on healthy humans could be shown. The European Food Safety Authority also states that taking 1-5 mg of vitamin B12 – an even higher dose – does not cause any side effects for at least 5 years every day.(2)

B vitamins are responsible for energy production, nerve health, stress tolerance, mood, thyroid health and more. A diet rich in variety and quality with proteins, legumes, cereals, vegetables and fruits should be the basis of the diet to meet the daily needs.

(1) Brasky ™, White E, Chen CL. Long-Term, Supplemental, One-Carbon Metabolism-Related Vitamin B Use in Relation to Lung Cancer Risk in the Vitamins and Lifestyle (VITAL) Cohort. J Clin Oncol 2017; 35: 3440-8.
(2). EFSA. Tolerable upper intake levels for vitamins and minerals. Scientific Committee on Food. Scientific Panel on Dietetic Products, Nutrition and Allergies. European Food Safety Authority 2006.

swisse still waiting….

Παίρνετε αρκετή βιταμίνη Β12; Πολλοί άνθρωποι δεν το κάνουν και η συνεπακόλουθη ανεπάρκεια στην συγκεκριμένη βιταμίνη μπορεί να προκαλέσει κάποια σοβαρά προβλήματα. Συμβάλλει σημαντικά στην παραγωγή του DNA και των ερυθρών αιμοσφαιρίων. (src)

Vitamin B12 is not made in plants; it is only synthesized by microorganisms. Strict vegetarians occasionally have difficulty obtaining enough vitamin B12, although the dietary requirements for vitamin B12 are very low (the RDA is 6 µg/day). (src)

By: |26/10/2017|categories: /