Should Vegans Take B12?


Should Vegans Take B12?

If you’ve been following my blog this year, you know I’m a big Dr. Michael Greger fan. I’ve read all his books and watched almost all his 1800-plus NutritionFacts videos. One video I recently watched has really weighed on my mind.

It begins with Dr. Greger looking at an article published in the Frontiers of Neurology and Neuroscience medical journal. The focus is the link between Leonardo da Vinci’s suspected vegetarian diet and the stroke which debilitated him for the last five years of his life.

The authors suggest that his diet might have raised da Vinci’s homocysteine level, resulting in the stroke. Dr. Greger explains:

“A suboptimal intake of vitamin B12, which is common in those eating plant-based diets unless they take B12 supplements or regularly eat B12-fortified foods, can lead to an increased level of homocysteine in the blood.”

While he says the debate is ongoing, many medical experts think elevated homocysteine increases the risk of stroke.

If the article’s authors are correct, Leonardo has plenty of company. Oxford researchers analyzed partial findings from the much larger EPIC-Oxford cohort study by looking the B12 levels of 689 subjects.

They found a deficiency in:

  • 52 percent of 232 vegans

  • 7 percent of 231 vegetarians

  • 0.4% of 226 omnivores


More than half the vegans weren’t getting adequate B12!

Dr. Greger goes on to review a 10-trial meta-analysis of 44,224 participants that showed participants given homocysteine-lowering drugs were more than five times less likely to suffer stroke than those given a placebo.

And the full EPIC-Oxford study?

It collected data from more than 48,000 meat eaters, fish eaters and vegetarians over 18 years. One-fourth of the vegetarians and nearly three-fourths of the vegans were “depleted or deficient” in B12. They also had resulting in extraordinarily high homocysteine levels.

Dr.Greger compared those numbers to the findings of a study of 45 U.S. Seventh-Day Adventist vegans. All had normal B12 and homocysteine levels, with no increase in the risk of stroke.

What accounted for the difference?

Fortifying organic foods with B12 is legal in the U.S., but not in the UK. Without consuming fortified foods or taking B12 supplements, the Oxford study’s participants were much more likely to develop a deficiency.

There’s no argument about the incredible health benefits of a plant-based diet. That said, deficient Vitamin B12 and elevated homocysteine can irreparably damage the brain by narrowing the arteries carrying its blood supply.

Historical documents depict Leonardo da Vinci as “… a vegetarian who respected and loved animals.” If only he’d known what we do about B12’s importance, perhaps he could have avoided the stroke in later life.

You may be attracted to plant-based eating for your own, the Earth’s, or the animals’ health (ideally, all three!) No matter what motivates you?

Please make B12 supplementation part of your diet.

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