The only reliable vegan sources of B12 are foods fortified with B12 (including some plant milks, some soy products and some breakfast cereals) and B12 supplements. Vitamin B12, whether in supplements, fortified foods, or animal products, comes from micro-organisms. Most vegans consume enough B12 to avoid anemia and nervous system damage, but many do not get enough to minimize potential risk of heart disease or pregnancy complications

algea and bacterial

I think Pumpkin also source of vitamin B12

Yes, dairy products such as milk, yogurt and cheese are sources of vitamin B12.

Please take a look at this useful RG link.

Article Vitamin B12-Containing Plant Food Sources for Vegetarians

Vitamin B-12 foods for vegetarians

• Dairy products. One of the simplest ways to consume adequate vitamin B-12 when you are vegetarian is to eat dairy products: ...
• Eggs. Another source of B-12 for vegetarians is eggs. ...
• Fortified cereals. ...
• Nutritional yeast. ...
• Nori.
• Shitake mushroom.

Another study:

https://www.eurekalert.org/pub_releases/2018-05/uok-uok051718.php

Regards,

Joachim

Thanks for valuable information Joachim sir

Green alga Chlorella vulgaris contain 10-50 μg of vitamin B12 per 100 gm of dry weight.

Yes, it is source for vegetarian

The only reliable vegan sources of B12 are foods fortified with B12 (including some plant milks, some soy products and some breakfast cereals) and B12 supplements. Vitamin B12, whether in supplements, fortified foods, or animal products, comes from micro-organisms. Most vegans consume enough B12 to avoid anemia and nervous system damage, but many do not get enough to minimize potential risk of heart disease or pregnancy complications

Pumpkin also source of B13

The world of micronutrients still has many gaps, and the specific case of vitamin b12 is particularly complex given the clinical importance of its levels, which are low, but also high. In this sense, in complement to the debate question, I want to share with you the following manuscript detailing the aspects associated with high levels of vitamin b12.

Article Hipervitaminosis B12 una mirada desde la atención primaria