Earlier quoted context omitted.
Why not just take B12 produced with microbes (= most supplements)? Those are considered vegan. Trying to get B12 from algae sounds unnecessarily complicated, considering our B12 has in all of our history been of microbial origin. But I also wouldn’t shun algae just because they occupy some B12 transporters. There’s all kinds of metabolic tradeoffs with every kind of food, and we are designed to tolerate that. Most me…
Oh I remember now I was actually looking at spirulina for omega 3. Seemed hard to find numbers, but one source said 331mg of EPA per gram of Spirulina platensis ( https://www.ripublication.com/ijac16/ijacv12n4_05.pdf ). Was considering what it would be like to eat like 6 grams of spirulina for 2g of EPA, versus that in one teaspoon of fish oil (high EPA type). But got stuck on the B12 blocking stuff. I wonder if your…
Re testing, the article you linked has another article linked on the same site: https://www.b12-vitamin.com/analogues/ They mention MMA testing here (you could get one as part of the Organic Acids Test at „The Great Plains“ lab for example), but that’s quite expensive ($299 right now). It’s maybe the most accurate B12 test out there. Technically, it’s a test by proxy.
If you are currently serum B12 deficient, then there’s probably not that much to worry about, because the B12 analogues in algae also won’t be absorbed properly (maybe due to a lack of intrinsic factor). Supplemental methyl- and adenosyl-B12 don’t have that problem.