[www.ncbi.nlm.nih.gov][www.ncbi.nlm.nih.gov] But then there is the MMA quandry. Can the active Vitamin B-12 in mushrooms reduce MMA.

Perhaps if you don't like taking supplements, these mushrooms could be a new part of your nutrient coverage along with nutritional yeast (Red Star enhanced), chlorella and possibly with regular MMA testing. In spite of the discovery which I plan to use as more of a talking point against the claim that "plants have no b-12" which is now patently false. The B-12 issue for vegans hasn't changed that much. We still need a reliable source of b-12 whether through supplements or a combination of yeast/chlorella & nori/mushrooms & testing.

"[jacknorrisrd.com]

A 2012 study from the Watanabe group (1) was released today on PubMed. I have added the following to B12 in Tempeh, Seaweeds, Organic Produce, and Other Plant Foods.
They found what they thought was active vitamin B12 in the following mushrooms (per 100 g of dry weight):

2.9 – 3.9 µg in black trumpet (Craterellus cornucopioides)
1.3 – 2.1 µg in golden chanterelle (Cantharellus cibarius)
1.3 µg in parasol (Macrolepiota procera)
.3 – .4 µg in porcini (Boletus spp.)
.2 µg in oyster (Pleurotus ostreatus)
.1 µg in black morels (Morchella conica)

The authors noted that 100 g of dry weight was the equivalent of about 1 kg of fresh mushrooms. They said that a moderate intake of black trumpet or golden chanterelle “may contribute slightly to the prevention of severe B12 deficiency in vegetarians.” They did not know why the mushrooms contained B12 and also did not test the mushrooms in humans to determine their ability to lower methylmalonic acid (MMA) levels.
As always, I will add a word of caution that vegans should not rely on any plant food for vitamin B12 until a number of batches have consistently lowered MMA levels in humans."

I remember I've heard about natural vitamin D in mushrooms. If you flip them over and put them under the sun, they 'grow' vit D. But it is D2, which is not as good as D3.

I do not believe mushrooms are plants...

Fungi are more closely related to animals than plants:

Quote

Animals and Fungi: Evolutionary Tie?
By NATALIE ANGIER
Published: April 16, 1993

They may seem awfully vegetative in their habits, and the university researchers who study them may often be counted as members of the botany department, but fungi are turning out to be far more closely related to animals than to plants, scientists say.

In a new analysis of genetic relationships among organisms with complex cells, including sponges, protozoa, algae, plants and animals, researchers have concluded that animals and fungi share a common evolutionary history and that their limb of the genealogical tree branched away from plants perhaps 1.1 billion years ago. Fungi and animals then went their own way some undetermined time after that.

The new findings, which appear today in the journal Science, suggest that the common ancestor of animals and fungi was a so-called protist, a single-celled creature that very likely possessed both animal and fungal characteristics -- perhaps spending part of its early life cycle in a membranous and mobile form resembling a human sperm, and at a different stage growing a stiff cell wall similar to that seen in today's fungi.

[www.nytimes.com]

Fungi digest plant foods to obtain nourishment like animals but do so externally. And, like animals, they need B12.

hmmm, point taken, still mushrooms cannot be considered animal.