Tuesday, December 18, 2007

Vegan must-knows on Vitamin B12

As you are reading these sections please keep in mind that the science of measurement and definitions of normal vs. optimal levels for these substances is still evolving. Plus there is incomplete standardization of these tests in the US - meaning the reference normal range may be different from one lab to the other. But these few paragraphs will give you a good background with which to interpret new discoveries and opinions as they emerge!

Vitamin B12
One of my favorites (such a complex and hotly debated vitamin). There are only a few essentials you need to know - but they are important to understand fully. The active forms have a variety of ___-cobalamin names, but you will mostly hear about B12 as "cyanocobalamin". Now we know why we call it B12 for short.

B12 is only made by bacteria and fungi, which explains why we have a hard time finding it in our modern antiseptic foods. Ruminants like cows have b12 because bacteria in their gut make it for them (and thus eating or drinking cows provides b12). Our intestinal bacteria also make B12, BUT these little guys live away from the place in our intestines where we are able to absorb B12...this is why we must eat B12.

Take B12 seriously - B12 deficiency is not rare. A prolonged deficiency of B12 has serious yet reversible effects (such as anemia - low red blood cell levels) and even more serious but irreversible effects (such as subacute degeneration of the dorsal columns - permanent damage to nerves that enable you to feel the floor and stay balanced, which is something I have a hard time doing even with normal dorsal columns).

Low B12 levels are also associated with depression and other neurological conditions.

Here's the good news - B12 is cheap, it has little if any side-effects, you need very little of it (around 2-3 micrograms/day) and you (well your liver) can hoard stores of b12 for one or more years (you'll hear ranges from 1-7 years, but NOTE: you will eventually run out if you don't eat any b12). Your liver, at least, understands how important this vitamin is!
Now here's the thing - B12 deficiency is more common than we'd like in both non-vegans and vegans. Why? Because most b12 deficiency is not from eating too little, but rather from being unable to absorb it (for reasons I wont get into here)...This said, vegans do consistently have lower levels of B12 than non-vegans.

So here's what you should do:
1/ make sure you have a reliable daily source of b12. These include a multivitamin, B12 supplement or fortified soy or rice milk, fortified cereals and "cliff" bars (or similar).

Yes you might be able to get B12 from a few dietary sources (e.g. Red Star Brand nutritional yeast, marmite). And there are some folks who claim other sources have b12 (traditionally made tempeh, your gut bacteria, blue-green algae, nori, etc.) but it is highly unlikely that these sources provide adequate amounts of B12 for all people. And frankly it is foolish to bet our nerves and blood on it. To complicate matters some of these other "sources" have "inactive" B12 analogues which can compete for absorption in your gut with active B12 thereby worsening your real B12 levels - another reason not to count on these less reliable sources.

I realize some people think there is something "unnatural" and bad about taking supplements, but it is the price we must pay for eating less dirt, feces and insects than our primate ancestors.

being vegan gets you a free b12 level lab test. Actually it may get you as many as you want! This is because doctors are classically conditioned to associate the word vegan with the word b12 deficiency. It's part of the fun training we get. So get your b12 level checked and find out where you stand.

The B12 blood test your doctor will do is not a perfect test (like most tests we use), so the result may need some interpretation. For instance, if it comes back in the upper half of normal (often >400 pg/mL) - rock on, it's normal. Recheck once in about 2 years. And keep eating a reliable daily source as per above. If it comes back "normal" but it's at the very low end (say below 300/350) then you should request a more specific test (e.g. methylmalonic acid and homocysteine) to make sure all is kosher. Talk to your doctor about this. Assuming the confirmation test is normal, you still need to be extra diligent about taking in b12 at least once per day and consider a repeat lab in 3-6 months . If a confirmation test or your initial test comes back "deficient", then you have some important work to do with your doc. (Note: an alternative strategy for a low-normal B12 is aggressive supplementation for a few months and then recheck with the standard test. Also note that labs may use different units such as pmol/L).

Look for updates on the topic of what the optimal b12 range is. If indeed it is optimal to be above 300-350 pg/ml, than that would mean a huge proportion of people around the world have deficient B12 levels. Yes this may seem extreme, but it is not an impossibility in our modern sanitized world - which has eliminated our 'natural' exposure to B12.

B12 Summary - find a daily reliable source, get your B12 level checked - it's simple.

For the clinically/medically minded see this article in the AAFP for a good B12 review.

For a nice informal review of B12 studies relating to vegan diets see this article from the 35th World Vegetarian Congress

As always, this blog does not provide individualized medical advice - for that you should find a good doctor.
If any of the above is unclear, please feel free to post related questions.

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Saturday, November 24, 2007

The fears of a suspecting vegan. Answered.

Maybe you're a touch freaked out about becoming vegan...about abandoning the dietary staples that billions of dollars in marketing have told you are essential to a happy successful productive and fertile life?

You're asking yourself: "But, where will I get my protein?!!!"

Now, I do believe that you're genuinely concerned about your amino acid pool, though I think what you're really asking is: how easy is it for me to screw this vegan business up and end up a crippled wreck? What do I really need to worry about? And what can I chill out about?

Important questions. Here is my answer:

If you're vegan, there are 5 major concerns you should address:

Pssst. don't tell anyone, but you should concern yourself with these things even if you're not vegan. Oh, and I have a much longer list for non-vegans, but I'll spare you that for now.

From easiest to tackle to hardest:
1. Vitamin B12
2. Vitamin D
3. Omega 3 Fatty Acids
4. Befriending refined Carbs
5. Getting cozy with isolation


Notice that protein isn't on this list. But it does get an honorable mention in my rant on carbs...so read on! If I had to list a number 6, it would probably be Iron (mostly for women) and 7 might be getting enough calories (though this would only apply to maybe 10-20% of us at most)...

Update: This blog will provide a BRIEF overview of the above worry list and I will wax philo-medical on each topic in more detail in separate blogs. If you're interested in topics 6 or 7 let me know and I'll happily offer a spiel!

1. Vitamin B12 - the vitamin that makes doctors and scientists alike wave their big wobbly index finger at us crazy vegans. And they are right (but they conveniently forgot to wave it at themselves as well) - you need to hunt out little bits of this vital substance and get your B12 level checked periodically. Read why and how by clicking here.

2. Vitamin D - the sunshine vitamin. Understanding this master vitamin will give you a new found respect for that golden globe that warms our spirits. Vitamin D deficiency runs surprisingly rampant in us northerners and it's so easy to prevent. In the least, take a supplement in the fall and winter. Read why and how by clicking here.

3. Omega-3 - the rarest of the "essential fatty acids". It's the fat you need in your diet for your heart, brain and maybe more. But omega-3s are a little tricky to find in good quantities unless you're a regular fish eater (which I'm guessing you're not). Read why and how to get vegan sources by clicking here.

4. Refined carbs - unlike D, B12, and omega-3s the problem here is that these little devils are just too easy to find and they are awfully tasty. We all (vegan or not) need to crack the whip and get these foods off the everyday menu. But they are everywhere. Like mosquitoes ruining a good sunset picnic. Take a hard look at what you eat and you'll be surprised. Read about your options for switching to whole grains, and why that's important, here.

5. Avoiding isolation - say what?! I don't eat isolation. Thank goodness you don't, because being vegan can be a good recipe for adding isolation into your life.

Let me rewind for a second. I've often asked myself: if eating animal foods is so damn harmful and eating plant foods so protective, why doesn't the medical literature abound with data that blows the efforts of our friendly meat and dairy lobby groups to smithereens? (Don't get me wrong - it does support the benefits of a whole food vegan diet).

Well, one answer (of many) may be that people who choose to buck society and become vegan are different. Maybe (and for good reason) they are more often depressed about the world they see around them. Maybe (and for good reason) they feel different and more isolated from the average Joe or Jane. Maybe there is an unspoken psychological toll that befalls those of use who care deeply about what we eat and what we don't. No, I'm not advocating ignorance - just that as a community we need to start thinking and talking about this. I'll muse on this more, tell you why I think it deserves a place on the top 5 list and offer a few suggestions on the topic if you click here 

The unofficial 6th worry: keeping it in context.

I want to be clear - eating a whole-foods vegan diet is a great way to help maximize your health and make the earth a better place. It's a great way to bring purpose and meaning into your life, to minimize cruelty to animals, to lessen your environmental foot-print and hey, it may even help you stay lean in America.

But let's face it, eating vegan doesn't cure malaria or prevent SUVs from running you over. Being Vegan = one important piece of the puzzle, but it rarely stands alone. There are many other important determinants of health and well-being. But we can muse more on that later.

Oh, and worrying IS bad for you. So take action on these concerns, but don't let them cause undue stress!
Note: take everything you read on The Internet with a grain of salt. My writings do not constitute individual medical advice - for there is no advice that applies to everyone. These are just my informed opinions and I hope they can provide some guidance in your quest for wellness. In short: Please don't sue me. I'm Canadian.

One final disclaimer: my views do not represent the views of my employers or the academic centers I have been fortunate to attend.

Thanks for reading this. Feel free to comment, or offer suggestions on further blogs...

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