Consider this: Do mushrooms require B12? Why would mushrooms adsorb and absorb the B12? Is this an accident of Nature; or ~ is DNA much more intelligent than we realize?

In AUSTRALIA ~ University of Western Sydneycompleted ground-breaking research on the B12 content of button mushrooms.

In JAPAN ~ According to Dr. Kanichi Mori, Shiitake mushrooms have more vitamin B12 than milk and fish.

Brief: ~ Certain types of Mushrooms are unique in that they contain Vitamin B12, something that vegetables can’t produce at all. Since B12 is mainly of animal origin, deficiency is commonly associated with vegetarian diets. Mushrooms were found to contain 0.32-0.65 mg per gram of B12, allowing just 3 g of fresh mushrooms to provide the RDA of this vitamin. Vegetarians may find this a useful way of getting this important nutrient. ~ more at http://www.polymathium.com ~ This is possibly due to a subtle, potential symbiotic relationship that occurs between the three parties involved… humans, mushrooms, and B12 producing bacterium.

In AUSTRALIA

Australian Government Analytical Laboratories found appreciable amounts of B12 in mushrooms.

There has long been speculation about whether or not mushrooms provide vitamin B12, a vitamin normally associated with animal foods. In 1987, the Australian Government Analytical Laboratories found appreciable amounts of B12 in mushrooms.

Based on this analysis, the mushroom industry then included B12 as a nutrient in their promotional material and advertising. The B12 level was disputed by some nutrition professionals who believed that only animal sources can provide B12, while others wanted to know whether the B12 claimed to be found was bio-available.

In early 2009, researchers at the University of Western Sydney completed ground-breaking research on the B12 content of button mushrooms. Their detailed experiments on mushrooms of all sizes and stages of growth from around Australia conclusively proved that:

A. Mushrooms do have B12 present. It is on both the surface of the mushroom and in the flesh of the mushroom. The majority of B12 is in the surface of the cup of the mushroom.

B. The B12 present is bio-available, in exactly the same form as B12 in beef liver and fish.

More on B12 content in Tempeh, Seaweeds, Organic Produce, and Other Plant Foods, below…

Summary: No food in Europe or the U.S. other than Japanese Nori, has been tested* for lowering MMA levels (*at the time of publication of this original article).

Thus, the discussion about whether Western vegans can get B12 from plant foods can, and probably should, end here (until proper research is conducted). Because so many plant foods have failed other tests that do not measure up to the MMA lowering test, and because there are so many false rumors being passed around, the studies of B12 in plant foods are examined in detail below.

The only plant foods which have been tested for B12 activity using the gold standard of lowering MMA levels in humans are dried and raw nori from Japan. Dried nori made MMA status worse, indicating that it can reduce B12 status and can possibly harm people who are B12-deficient. Raw nori kept MMA levels about the same, indicating that it didn’t harm B12 status, but it did not help either.

Of all the foods studied below, only tempeh in Indonesia or Thailand, dulse, Chlorella, raw nori, Aphanizomenon flos-aquae, and coccolithophorid algae warrant much further attention for providing B12. Unless these foods are shown consistently to correct B12 deficiency, vegans should not rely on them as a B12 source.

It would be great to find a reliable plant source of B12 for vegans. One might get the opposite impression given my level of critique of some of these studies. My skepticism is only due to the potential harm from relying on a food that contains inactive B12 analogues which can make a B12 deficiency even worse.