Michael Greger MD

Michael Greger MD

Posted September 10, 2011

Published in Health

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Ask the Doctor: Q&A with Michael Greger, M.D.

Read More: Ask the Doctor, cholesterol, eggs, lycopene, raw food, supplements, tomatoes, vitamin B12, vitamin D

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With hundreds of videos on more than a thousand topics and new content every day it may be hard to keep up with! So I thought every weekend I'd start reposting some of the most popular back-and-forth of the week:

cmcauliffe asked on my blog post Bad Egg : I have recently read that there is a difference between commercial eggs and farm eggs -- I have six chickens that roam freely, and I use the eggs for cooking, for the occasional breakfast, and even for a dinner at least once a week. Am I wrong to think my eggs are healthier? Thanks!

My response: That may be true of pasture-raised birds, but a new study published this summer found no significant difference between cholesterol levels in "free-range" compared to conventional eggs (over 200mg per jumbo egg in each case). Free-range eggs are certainly better from an animal welfare standpoint, and also less likely to be contaminated with Salmonella (the leading cause of food-borne illness related death in the United States), but don't appear to have less cholesterol, the most important health reason to minimize one's egg intake.

Jen Ferdinand asked on Vitamin Supplements Worth Taking: Hi Dr. Greger. I noticed the bottle of Vitamin D in this video was Vitamin D2. I have read that D3 is the better source for us (cholecalciferol). Can you please clarify?

My response: Such a good question. Taken daily in doses under 2000IU, vitamin D2 (ergocalciferol) and D3 (cholecalciferol) appear bioequivalent (meaning they both work just as well in your body). However if your physician suggests you take large intermittent doses (such as 50,000IU weekly, then D3 is probablysuperior).

Veguyan asks on Raw Food Diet Myths: I heard that the lycopene boost from raw tomatoes in a Vitamix is just as potent as the lycopene boost from a cooked tomato sauce. I heard this from a Raw Fooder. What do you say?

My response: I'm afraid your raw fooder friend may have been misinformed. As you can see here, the heating itself seems to improve the bioavailability of lycopene. I would not be surprised if the blending helped too, though, so you could blend and heat and have the best of both worlds :)

Vas Bouras asks on my blog post Vegan B12 deficiency: putting it into perspective: What would you recommend as far as the best way to get B12 vitamins into our system, supplements? Will any over the counter supplement do? If one were lacto-ovo vegetarian, do they get vitamin B12 from cheese and eggs?

My response: I'm so glad you asked! In my opinion, the easiest and cheapest way to get our B12 is to take at least 2,500 mcg (µg) cyanocobalamin once each week, ideally as a chewable, sublingual, or liquid supplement (you can't take too much-all you get is expensive pee).

Or, if you'd rather get into the habit of taking something daily (instead of once-a-week), I recommend at least 250mcg (I know the math doesn't seem to "add up" but that's due to the vagaries of the B12 receptor system-I'm going to post a video on how I arrived at these recommendations soon).

Or, if you'd rather get it from B12-fortified foods, I'd suggest three servings a day, each containing at least 25% of the "Daily Value" on its label (again, I'll explain). Such foods can be as exotic as a certain type of "nutritional yeast" or as simple as a bowl of Cheerios.

As I'll show in my video on Saturday, ovo-lacto vegetarians are also at risk for deficiency. Eggs and dairy are not good sources of vitamin B12 (in part because foods come as a package deal and eggs and dairy bring along as baggage saturated fat, cholesterol, and hormones).

Every video and blog post has a comments section. Please feel free to join in on the conversation and to leave any ask-the-doctor questions you may have and I'll try to get to them as soon as I possibly can. Hope everyone's having a great weekend!

-Michael Greger, M.D.