I recently received a question from a 66 year old client who was taking the Vegan Society’s Veg-1 supplement 1 . He had read somewhere on the internet that he should be taking 1000 mcg per day of vitamin B12 instead of the 25 mcg that the Veg-1 tablets contain. This seemed like something worth discussing further; after all, B12 is the only vitamin supplement that almost all authorities state is vital for those who eat an exclusively plant-based diet.
Additionally, there are studies2 showing the importance of additional B12 intake as we age, studies3 showing the widespread deficiency in B12 levels in all groups, including meat-eaters; and there are studies4 5 indicating that an individual’s ability to absorb B12 is probably more important than simply looking at the quantity taken as supplements.
To avoid confusion, it’s worth explaining that you may come across different ways that the metric system microgram is expressed. You will see either the symbol “μg” used or the symbol “mcg” used for microgram. And, by the way, a microgram is a unit of mass equal to one millionth (1×10−6) of a gram. The μg symbol is the standard unit according to the International System of Units or the SI units 6 , whereas the mcg symbol is a lot easier to type on the QUERTY keyboard and is, therefore, likely to appear more in general, non-scientific literature.
Contents of Veg-1
The form of B12 in the Veg-1 supplement is cyanocobalamin. Another common form of supplemented B12 is methylcobalamin. Dr Greger recommends7 cyanocobalamin, partly because it’s the cheapest.
It is described as “A chewable [orange or blackcurrant] flavoured multivitamin formulated by The Vegan Society in conjunction with HealthPlus. Designed specifically for vegans, but suitable for everyone, this supplement provides EU recommended Nutrient Reference Intake (NRV) of:
- Vitamin B2 (1.6 mg – 114%) – Riboflavin
- Vitamin B6 (2 mg – 143%) – Pyridoxine Hydrochloride
- Vitamin B12 (25 µg – 1,000%) – Cyanocobalamin
- Vitamin D3 (20 µg – 400%) – Lichen Cholecalciferol Prep.
- Folic Acid (200 µg – 100%) – Folacin
- Iodine (150 µg – 100%) – Potassium Iodine
- Selenium (60 µg – 109%) – Selenomethionine Prep.
- Stearic Acid
- Natural Flavour (Orange or Blackcurrant)
- Magnesium Stearate
*Polyvinylpyrrolidone (PVP) is considered a safe ingredient and has been rated as a low hazard ingredient by the Cosmetics Database.[We will leave aside, for the time being, whether or not the other included vitamins, minerals and various ingredients are necessary/healthy.]
The supplement comes in bottles of either 90 or 180 tablets which are a three or six month supply for adults respectively.
Directions: “One tablet per day for adults. Half a tablet per day for children aged 2-12. Always chew or crush tablets for maximum absorption. Do not exceed recommended intake.”
Vitamin B12: A variety of viewpoints
This is a topic that receives different responses from different experts, so rather than state my opinion, I will present a range of views and leave it to you to make up your own mind based on the indicated research.
Dr Michael Greger:
“For adults under 65 years of age, the easiest way to get B12 is to take at least one 2,500 mcg supplement each week or a daily dose of 250 mcg. For those over 65 who eat plant-based diets, the supplementation should probably be increased up to 1,000 mcg … each day.”8[This would NOT be covered by the 25 mcg in Veg-1.]
Dr John McDougall:
“As little as 0.3 to 0.65 micrograms per day of vitamin B12 has cured people of megaloblastic anemia; however, to add an extra margin of safety I have recommended a higher dosage of 5 micrograms per day. You may be surprised to discover that you cannot purchase these tiny dosages. Supplements sold contain 500 to 5000 micrograms per pill. These exaggerated concentrations will correct by passive absorption B12 deficiency caused by disease of the intestine. Everyone else is being overdosed by a factor of 1000. If you are an otherwise healthy vegan and are using typical dosages of B12 (500 micrograms or more per pill), a weekly dose of this vitamin will be more than sufficient.” 9[This would be covered by the 25 mcg in Veg-1.]
Dr Neal Barnard:
“Regular intake of vitamin B12 is important to meet one’s nutritional needs. The recommended dietary allowance in adults is 2.4 micrograms per day, with increased requirements for women who are pregnant or breastfeeding.”10[This would be covered by the 25 mcg in Veg-1.]
Dr Thomas Campbell:
“For the general adult population, a daily dose of the smallest available tablet of B12 (usually 100 mcg) should be sufficient. You require just a few micrograms a day. Your body will absorb only a very small part of that pill. The reason for this low absorption is that there is only enough intrinsic factor (the body’s chemical that shuttles B12 into your gut cells) excreted per meal to absorb 2-4 micrograms of B12. In addition, your body absorbs B12 by passive absorption, but it does this with only perhaps 1% of the total dose you consume (the percentage decreases with higher dosages). I suggest a dosage just high enough to give you a nice low-average level of B12. I do not suggest B12 for anything other than to prevent deficiency.” 11[This would be covered by the 25 mcg in Veg-1.]
Dr Dean Ornish:
“The RDA (Recommended Daily Allowance) for B12 is 2.4 micrograms. A person stores between 2 and 5 milligrams of vitamin B12 and only excretes a very small fraction of it each day. Nevertheless, over time, vitamin B12 deficiency can develop if stores are not replenished from diet or from supplements. It’s important to understand, however, that the body’s ability to absorb vitamin B12 from dietary supplements is largely limited. Only about 10 mcg of a 500 mcg oral supplement is actually absorbed in healthy people. According to the National Institutes of Health, when a person relies on dietary supplementation for B12, it’s helpful to strive for about 25-100 mcgs to maximize potential absorbed.” 12[This would be JUST covered by the 25 mcg in Veg-1.]
Dr Joel Fuhrman:
“We need to take 100-200 mcg per day.” (Section taken from a transcript of his telephone interview on the video – at 1 minute 35 seconds.)13[This would NOT be covered by the 25 mcg in Veg-1.]
Dr Caldwell B Esselstyn:
“[For] Vitamin B12…I favor 1000 mcg daily.” 14[This would NOT be covered by the 25 mcg in Veg-1.]
“If you’re using supplements, you need 1000 mcg at least twice a week. That’s if you’re using cyanocobalamin. But if you’re using methylcobalamin or adenosylcobalamin, you may need it more often – 1000 mcg daily because these are a little less stable than cyanocobalamin.” 15[This would NOT be covered by the 25 mcg in Veg-1.]
More information on different forms of cobalamin is available 16 .
NIH (USA National Institutes of Health):
“Adults – 2.4 mcg” daily.” 17[This would be covered by the 25 mcg in Veg-1.]
NHS (UK National Health Service):
“Adults (19-64 years) need about 1.5mcg a day of vitamin B12.” 18[This would be covered by the 25 mcg in Veg-1.]
EFSA (European Food Safety Authority):
“[T]he Panel sets an Adequate Intake (AI) for cobalamin at 4 μg/day for adults based on data on different biomarkers of cobalamin status and in consideration of observed mean intakes, which range between 4.2 and 8.6 μg/day in adults in several EU countries.” 19[This would be covered by the 25 mcg in Veg-1.]
WHO (World Health Organisation):
“The ideal amount of supplemental vitamin B12 is less clear. Although the recommended daily intake is 2.4 µg/day, many elderly persons appear to require supplement doses many times higher to achieve optimum vitamin B12 status, probably due to limited absorption. The supplements can be given daily, or as a larger dose less frequently…” 20[This would be covered by the 25 mcg in Veg-1.]
Since there is a store of B12 in our bodies that is thought to last for a long time, (opinions differ on length of time from months to decades!), I don’t worry too much about B12 for the first couple of weeks of WFPBD programmes. However, for longer term adherence to the diet, it is something that does need to be addressed and maintained.
No matter how long my clients are on a WFPBD programme, I ask them to have blood tests at the start and end of the programme. The blood test will always include results for B12 levels.
If, however, you are still confused or worried about this subject, I suggest you think about the following:
- Speak to your doctor and ask his/her professional opinion
- Increase your daily intake to the 1000 mcg Dr Greger recommends – as he says, there is no known overdose and excess will simply be expelled in urine.
- Have regular blood tests (every 3, 6 or 12 months depending on how recently you have transitioned to a WFPBD).
B12 Fortified Foods
Regarding the foods fortified with B12: You should find that nutritional yeast, Marmite, plant milks (soy, almond, oat etc), and several soy products (tofu, tempeh etc) all tend to be fortified with B12. I would NOT recommend eating fortified breakfast cereals since these tend to be highly processed and are fortified with other unnecessary (and possibly harmful) vitamins/minerals.
If you have questions or concerns not covered in this article, write to me at firstname.lastname@example.org.
- The Vegan Society: VEG 1 orange 180 tablets
- Andrès E, Loukili NH, Noel E, Kaltenbach G, Abdelgheni MB, Perrin AE, Noblet-Dick M, Maloisel F, Schlienger JL, Blicklé JF. Vitamin B12 (cobalamin) deficiency in elderly patients. CMAJ. 2004 Aug 3;171(3):251-9.
- Allen LH. How common is vitamin B-12 deficiency? Am J Clin Nutr. 2009 Feb;89(2):693S-6S. Epub 2008 Dec 30.
- DOSCHERHOLMEN A, HAGEN PS. A dual mechanism of vitamin B12 plasma absorption. J Clin Invest. 1957 Nov;36(11):1551-7.
- Scott JM. Bioavailability of vitamin B12. Eur J Clin Nutr. 1997 Jan;51 Suppl 1:S49-53.
- International System of Units – SI
- Cheapest Source of Vitamin B12. Michael Greger M.D. FACLM February 7th, 2012 Volume 7.
- Vitamin B12. Dr Michael Greger.
- Vitamin B12 Deficiency—the Meat-eaters’ Last Stand. Dr John McDougall Newsletter Vol 6 No 11. 2007.
- Don’t Vegetarians Have Trouble Getting Enough Vitamin B12? Vitamin B12:A Simple Solution. PCRM.
- 12 Questions Answered Regarding Vitamin B12. CNS. February 6, 2015. By Thomas Campbell, MD.
- What is the Role of Supplements in a Healthy Diet? by Carra Richling on Ornish Living.
- How Much Vitamin B12 Should We Take & Why? Dr Joel Fuhrman. Video on Plant Based Science London YouTube site.
- Dr Esselstyn’s Latest Basic Recommendations. August 7, 2017. Food As Prevention.
- What Are The Biggest Mistakes Vegans Make? Video interview by Brenda Davis.
- Vegan Health: Methylcobalamin and Adenosylcobalamin
- Vitamin B12 Fact Sheet for Consumers. NIH.
- Vitamins and minerals. NHS Choices.
- EFSA Journal. Scientific Opinion on Dietary Reference Values for cobalamin (vitamin B12). EFSA Panel on Dietetic Products, Nutrition, and Allergies (NDA). First published: 9 July 2015 .
- Conclusions of a WHO Technical Consultation on folate and vitamin B12 deficiencies. WHO.