Chlorella Shown to Have B12 Activity in Humans—Caution Warranted
I have updated the article B12 in Plant Foods with a new study on B12 activity in Chlorella:
In a 2015 (USA) study, Merchant et al. fed 17 B12-deficient vegans and vegetarians a Chlorella pyrenoidosa supplement for 60 days (1). Average serum MMA levels decreased from 441 nmol/L at baseline to 301 nmol/L at 30 days and 297 nmol/L at 60 days. Average serum homocysteine levels decreased from 10.0 µm/L at baseline to 9.5 µmol/L at 30 days and 9.0 µmol/L at 60 days. No adverse effects were noted from the chlorella regimen.
• Average serum MMA levels appeared to stabilize on this regimen at above recommended levels. B12 deficiency is generally defined as serum MMA levels above 270 nmol/L, the same standard used in this study by Merchant et al.
• The study was funded by Sun Chlorella Corporation of Japan and the lead author of the study is a paid consultant.
• A daily regimen of 45 Sun Chlorella A tablets (totaling 9 g) were used in this study. That amount of tablets would be quite costly. While it might require fewer than 45 tablets to achieve the same results, we can’t tell from this study.
In summary, it appears that at least some batches of chlorella have vitamin B12 activity, but it’s too soon to know how much chlorella vegans would require for optimal B12 status.
1. Merchant RE, Phillips TW, Udani J. Nutritional Supplementation with Chlorella pyrenoidosa Lowers Serum Methylmalonic Acid in Vegans and Vegetarians with a Suspected Vitamin B(12) Deficiency. J Med Food. 2015 Oct 20. [Epub ahead of print] | link