Fortified foods, such as some breakfast cereals and types of nutritional yeast, can provide another cholesterol-free source of vitamin B12.
Update: data heroically procured by Vesanto Melina suggests that the nutrition facts label of Red Star brand’s “vegetarian support formula” nutritional yeast is misleading, and that one may only get 0.9 mcg of vitamin B12 per teaspoon. So to serve as a sole source, one would have to consume 2 teaspoons three times a day (4 to 6 hours apart). The video was updated and re-recorded on July 14, 2012 to reflect this fact. Thank you, Vesanto!
Note that nutritional yeast doesn’t naturally contain B12—it has to be fortified with the vitamin. So, many formulations lack B12 completely. For example, while Red Star brand’s “vegetarian support formula” nutritional yeast is an excellent source of B12, their “elder support formula” doesn’t have any—which makes no sense, as the Institute of Medicine recommends everyone over age 50 supplement with B12. So, if you buy it in bulk and are relying on it for your B12, you may want to ask to see the package it came from, just to check to make sure it has B12 in it.
If you’d rather just take a supplement once a week, see yesterday’s video of the day: Cheapest Source of Vitamin B12. And for an explanation of why fortified foods and supplements are the preferred source, see the video before that: Safest Source of B12. And to put the whole B12 issue in perspective, see Vegan B12 Deficiency: Putting It into Perspective. And if you’re sick of learning about B12, there’s only one more video in this five-part series: New Vitamin B12 Test.
2019 Update: My vitamin B12 recommendations have changed to reflect the latest science and labeling changes. If you’re relying on getting all your B12 from fortified foods, make sure you get at least one serving at each meal containing at least 190% of the Daily Value listed on the nutrition facts label (based on the new labeling mandated to start January 1, 2020–the target is 4.5 mcg three times a day). Probably easier to just follow my supplement recommendations instead, which have also changed: at least 50 micrograms of cyanocobalamin once a day or 2000 micrograms of cyanocobalamin once a week.
I put out some new B12 videos in 2020. Please see all of my newest videos on the topic page.
For more context, check out my associated blog post: Stool Size and Breast Cancer Risk.