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Probiotic and Vegan Supplements: An Insider’s Guide on What to Take – Dr. Michael Greger



Compared to the ways many fitness guru and celebrities workout, taking supplements is relatively simple: pop the pills, eat them … and then keep doing that for whatever results you want to achieve.

Of course, the idea is very different from the execution – and taking the right supplements is never a straightforward path.

To find out exactly how that works, today we’re speaking with Dr. Michael Greger again, in part 4 of our interview series.

Dr. Michael Greger is a renowned physician specializing in clinical nutrition, author, and internationally recognized professional speaker on on various public health issues. Dr. Greger is also the Founding member of the American College of Lifestyle Medicine, the Director of Public Health and Animal Agriculture at the Humane Society of the United States and Humane Society International. Dr. Greger’s work can be found at (One of my all time favourite websites!).

In this post, I’m going to share:

  • Why taking vitamin D is important if you don’t get enough sun
  • Why buying fresh produces is a more cost-effective and efficient solution to your health (vs. vegan supplements)
  • Why Dr. Greger prefers prebiotics to probiotics
  • One simple tactic to figure out if the probiotics you purchased actually works

And stay tuned, I’ll also be featuring another interview on supplements with even more juicy details to share!

Got Vitamin D?

vit d

Q: Let’s talk supplements. You advocate taking B12 supplements for vegans. What other supplements, do you think are worthwhile for vegans, as well as for omnivores?

Dr. Michael Greger: Depending on where they live and how much sun exposure they get, I’d recommend vitamin D.

So, we were never meant to live this kind of latitude. Now if you have a white enough skin and you live at a reasonable latitude, kind of Atlanta to LA towards south in the Northern Hemisphere, then you’ll probably get all the Vitamin D you need throughout the year. You’re getting 15 minutes of midday sun on the forearms and face.

But if you are darker skinned or you live in the rest of the U.S. (and higher latitude around the world) then during the winter months, you are just not going to make ideal levels of Vitamin D.

And, if you are inside at a computer all day or in a cubicle, or not getting midday sun, it doesn’t matter if you live in Hawaii, or Phoenix, you’re just not going to make any Vitamin D.

So, you need to take it a supplement. So, I recommend 2000 international units of Vitamin D a day.

Produces vs. Supplements?


Q: What supplements do you think that your audience should be a little bit more concerned about buying, or don’t necessarily need to buy?

Dr. Michael Greger: Basically everything else.

Every penny that we spend on a multi-vitamin is a penny that we could be spending on another bunch of kale or another plant of blueberries.

But there are certain conditions.

For instance, if you are an alcoholic you may need a number of Vitamin supplements. If you are pregnant you may have special needs.

But, unless there’s a problem, there’s no need to take other supplements.

We should get our nutrients from the produce aisle, not a supplement aisle.

Why Dr. Greger Prefers Prebiotics to Probiotics

Q: In terms of prebiotic vs. probiotic, why do you prefer prebiotics?

Dr. Michael Greger:

Prebiotics are what feeds the good bacteria we have. Probiotics are the good bacteria.

If we don’t have symptoms of gastrointestinal distress such as chronic diarrhea, or bloating, things like that, then you’ve got good bacteria doing their job. You just need to feed them. And that’s what most people are, in the kind of natural state.

Unless you are doing something funky like taking antibiotics or something, then you should have good bacteria so you’ve got to feed them.

And the food we feed the good bacteria are prebiotics, and the foods are essential fiber, and resistant starch.

Our bacteria eats the fiber that we eat. That’s the fuel for our bacteria. I mean we have trillions and trillions.

We have more bacteria cells in our bodies than human cells in our bodies. In fact the bulk of a stool is actually not undigested food, it’s actually bacteria, literally. By mass, if you look at our stool, more than half is literally just bacteria. We are a bacteria-churning factory.

They just keep dividing and dividing. So, no wonder, they have such an important impact on our physiology. And so we have to feed them.

We have got trillions of pets. You wouldn’t come home from work and not feed the dog. Well, you shouldn’t do that do your body.

So eating fiber and the resistant starch, starches that aren’t digested in our small intestine, will feed the bacteria. You can find fiber and starches from legumes, vegetables, fruit, and grains. Basically, fiber is found in all whole plant foods.

How to Test Your Probiotic Supplement

Q: Now, what about probiotics? If people were to buy them, how would you suggest selecting the best probiotic supplement?

Dr. Michael Greger: If you just had a course of antibiotic or something, where you wipe out the good bacteria in your gut, I think that would be a good idea, to do a course of probiotic supplements.

If you buy probiotics, you take it home and you take two bowls of milk. Whatever kind of milk you want, and open up a few capsules and put in the one bowl not the other bowl, and you go to bed.

When you wake up in the morning, pour both bowls in the sink, and they should look different. The one with the probiotic should be foamy, filmy, bubbly, and gross. If they both look the same, then the probiotic is dead. It works if it’s alive.

So you take it back to the store and get our money back. You just have to test it. It may be in our fridge or the refrigerated section of the supermarket. Or it’s been in a hot truck for a week. You have no idea. You just have to test it to make sure it works.

This is it for Part 4 of this interview.

Stay tuned here for Part 5 of the interview.