For reliable adequate intake of B12 vegans should consume either a supplement or fortified food that contains B12. Someone in social media coincidentally posted an interesting different opinion just after that. This is the follow up.
The social media post referred to this National Centre for Biotechnology Information (NCBI) article from 2014. The social media poster of the article stated the fascinating opinion that based on that NCBI article, B12 can be obtained adequately without food fortification nor supplementation from non-animal sources. This is of course a potentially very significant statement of holy grail proportions. That is since B12 is the only human required nutrient not available in plants (B12 is produced by micro-organisms).
A quick message was thus sent to The Vegan Society asking for an opinion on that article. The replied received stated:-
- The review by Watanabe et al [in that article] is incomplete and in particular omits the human study by Yamada which failed to find a benefit of nori
- Jack Norris has a much better review at http://veganhealth.org/b12/plant#sbga
- The bottom line is that no randomised controlled trial has shown a convincing effect of any algae in improving B12 status. There was one recent uncontrolled study of chlorella and an earlier study of AFA (Klamath Lake algae) that suggested some effect. Neither give sufficient evidence to recommend these as reliable sources