I've been told completely contradicting information about Spirulina. Does anyone really know if this is a reliable source of vitamin b12?
Thanks!!!

i just got my bottle of spiruline and checked, but it didn't say anything about B12, so i went on their website, and it says spiruline has "Vitamin B12 - Natures richest source. Often lacking in a vegetarian diet."
Then i found the complete list of nutrients and their contents. Btw, this is for Synergy brand spirulina, it probs differs slightly brand to brand.
The full list can be accessed here:
http://www.synergynatural.com/research.html
It says that per 100g of spirulina, there is 230mcg in premium spiruline, and 274mcg in organic spirulina. mcg is micrograms, usually symbolised by the funny-looking u.
I went onto the Aus gov. National Health and Medical Research Council website, and found out the daily requirements.
Boys
9-13 yr 1.5 µg/day 1.8 µg/day
14-18 yr 2.0 µg/day 2.4 µg/day
Girls
9-13 yr 1.5 µg/day 1.8 µg/day
14-18 yr 2.0 µg/day 2.4 µg/day
also, you need more if you're pregnant.
SO, if you take the reccommended 6 tablets (15mg) of the premium spirulina, then you're getting 34.5micrograms of B12. Comparing this to the requirements as listed above, you're getting well over 10 times the minimums.
Apparently, overdose of B12 has been linked with some cancers and stomach conditions, but then again you have to consider that most people get B12 from meat, so it may not be the B12 overdose that's causing it, it's probably the real health problems from eating too much meat. Unless they start finding vegans getting cancer from B12 supplement overdose, I'm not convinced.