Can I live without it safely?
No. B12 is an extremely important vitamin supporting many bodily and psychiatric functions. Fun fact (and I need citation here) is that it is so important you can live without it for months, exactly because your liver caches it in case you don't intake any for a while.
How can I obtain this vitamin as a vegan?
With a ...
When in doubt, consult your doctor, and do bloodwork!
Iron. I have never had anemia problems and iron is replete in dark leafy greens.
Vitamin A. Primarily found in meats, but also in cooked vegetables. If you are a raw vegan you are at risk for Vitamin A.
Vitamin D. You are likely at risk anyway if you live in a northern climate. Vitamin D affects ...
The B12 in supplements is made from bacteria and sourced from bacteria cultures. It is not from animal products.
However, some supplements can contain gelatin in the capsule, which you should look out for.
Streptomyces griseus, a bacterium once thought to be a yeast, was the commercial source of vitamin B12 for many years (8, 9). The bacteria ...
Artificial vitamin B12, also known as Cyanocobalamin is produced by bacterial fermentation, as indicated here.
Technically, bacteria are far from being considered animals, so this method should be vegan-safe:
Once regarded as plants constituting the class Schizomycetes, bacteria
are now classified as prokaryotes. Unlike cells of animals and other
Nutrients of concern for Vegans
There are a few nutrients that may be more difficult to obtain on a vegan diet as compared to an unrestricted (omnivorous) diet.
b12 Vitamin B12 is easy, cheap, and safe to supplement. It is not reliably available from any plant-based foods. All vegans should take a vitamin B12 supplement.
fats EPA and DHA are long-chain ...
They are essentially the same molecule, but for one bond: cyanocobalamin has a CN- (cyanide) tied to the cobalt atom, while methylcobalamin has a CH3- (methyl). There are also adenosylcobalamin (also called 5-deoxyadenosylcobalamin, C10H12N5O4-, adenosine) and hydroxocobalamin (OH-, hydroxyl). While the latter should be more soluble in water, the amount ...
This depends on the B12 status the person had initially, and probably on other unknown individual factors. While there are no proven natural wholefood sources of B12 that are vegan, it's possible that some people obtain small quantities of B12 from unrecognised or incidental sources (since B12 is produced by soil bacteria) while others do not, so it's ...
According to this Medscape article, vegans and vegetarians children can obtain calcium from various sources such as: fortified soy formulas, soy milk, soy cheese, soy yogurt, and various other calcium-fortified foods
Dairy foods are a natural source of calcium for vegetarians and
nonvegetarians. Vegans can consume fortified soy formulas, soy milk,
The vegan society states the following:
In choosing to use fortified foods or B12 supplements, vegans are taking their B12 from the same source as every other animal on the planet - micro-organisms - without causing suffering to any sentient being or causing environmental damage.
Now, it's up to every person to decide for themselves whether or not they ...
From the Vegan Society:
To get the full benefit of a vegan diet, vegans should do one of the
Eat fortified foods two or three times a day to get at least three
micrograms (mcg or µg) of B12 a day OR
Take one B12 supplement daily
providing at least 10 micrograms OR
Take a weekly B12 supplement
providing at least 2000 ...
The Vegan Society currently advises that consuming spirulina has not been proven to prevent B12 deficiency. See their open letter on B12 which does not discuss scientific studies in detail, but gives advice based on the current evidence and consensus in nutritional science, rejecting spirulina as a possible source of B12:
Claimed sources of B12 that have ...
djechlin answer is quite complete. However, as an ex vegetarian I can confirm the importance of taking supplements for ensuring proper levels of B12.
1) Can I live without it safely?
It is not safe to have lower levels of B12. A mild form is having lower levels without anemia (like I had). However, on the long term it can lead to very serious problems like:...
1. General vegetarians (Non-vegans)
For non-vegans, dairy products seems to be the best source, as mentioned in other answers as well. List of top 4 (I'm excluding eggs):
The amount of vitamin B12 in cheese depends on type and variety, Swiss cheese provides the most with 3.34μg per 100g serving
(56% DV), followed by Gjetost(40% DV), Mozzarella(39% ...
Those who can't get to sleep at night may need vitamin B12. Studies
show that B12 causes an earlier release of melatonin at night which
resets the sleep-wake cycle. (Melatonin has been called "the sleep
hormone" because of its effects on sleep). B12 acts directly on the
pineal gland to provoke a faster release of melatonin. At the tail
end, B12 ...
This answer would be most likely the same for a non-veg*n question, since there is nothing specific that you should look out for as a result of your diet.
The bones are made mostly out of rigid form of collagen, which is a protein and composes the organic part of the bone and calcium phosphate and other salts, which create the hard outer layer.  Based ...
Nutritional yeast is best consumed in small amounts daily.
Nutritional yeast is a very high source of niacin (Vitamin B3). The tolerable upper limit (TUL) for niacin is set at 30 mg per day because some people experience uncomfortable facial flushing after consuming anywhere from 30-1000 mg of niacin per day. One tablespoon of nutritional yeast provides 28 ...
The matter is vast, so it's difficult to give a complete answer. I start a community wiki and I hope more participants to improve my answer.
The American Dietetic Association's "Position on vegetarian diets" suggests to increase iron consumption:
Because of lower bioavailability of iron from a vegetarian diet, the
recommended iron ...
Whilst the Vegan Society contains a more comprehensive list of the common deficiencies, I'm going to mention vitamin D.
Vitamin D supports your immune system and is thought to contribute to a positive mental state, though personally I think going out in the sun could just as easily have that effect regardless of its nutritional worth.
The reason it'...
Vitamin D is often treated generically, sometimes even not specifying the index. According to this article, there are five Ds (D1, D2, D3, D4 & D5) and only D2 (ergocalciferol) and D3 (cholecalciferol) can be used by our bodies.
This article goes further and makes a difference between D2 and D3. D3 is clear winner (my emphasis):
The majority of ...
It's not the oxalic acid, it's the calcium:
Potassium oxalate did not influence iron absorption in humans from a kale meal and our findings strongly suggest that OA in fruits and vegetables is of minor relevance in iron nutrition.
In short, calcium is extremely digestible in chloridric acid (some people even use it to polish marble)...
In nature, poultry get their B12 by pecking for insects and worms in the dirt. Since this behaviour is not possible on industrial farms, B12 is added to animal feed1.
According to the USDA, one cooked egg (50g) contains 0.56µg of vitamin B122. The recommended daily intake of B12 for people age 14 and older who aren't pregnant or breastfeeding is 2.4µg3, ...
For vitamin B12 oral intake, 1,000 mcg daily is both safe and sufficient.
Update: A recent randomized controlled trial of vegetarians and vegans who were marginally B12 deficient showed that 50 mcg B12 taken daily was sufficient to correct B12 status. Effect of two different sublingual dosages of vitamin B12 on cobalamin nutritional status in vegans and ...
Currently, there seem to be no natural plant food that would contain vitamin B12 in the amounts sufficient for humans.
Some plant foods contain vitamin B12, but this is either inactive - pseudovitamin B12 - (in spirulina, chlorella, tempeh, miso, kombu) or not present in sufficient amounts (in white button mushrooms, Korean purple laver or nori or ...
As you said, B12 is highly soluble in water and unused quantity is easily excreted from the body as urine. Therefore, it is nearly impossible to get an overdose of B12, even if you exceed the recommended daily intake.
However, the component which possibly have a very small risk is cyanocobalamin because it releases a tiny amount of cyanide within the body ...
The answer to the question would be largely the same as for identifying vegan anything.
First, look for the vegan label on the package. Usually this is either a nice green V, even nicer animal picture or, as Zanna suggested, this logo. Make sure this does not mean Suitable for vegetarians as this still may (and probably will) not be vegan.
If you could ...
If you're just buying at the supermarket, you really can't know. There are lots of hidden animal products, especially in supplements.
My advice would be to purchase them online from an all vegan website. That way you'll know they're vegan. Otherwise make sure the supplement specifically says vegan on it.
One basic thing to know is that B12 supplement absorption rate decrease with the total amount of B12 provided by the supplement (check here). In other words if you get your supplement daily then 1-2 mcg could be enough, but if you get it weekly it would be necessary to intake as much as 1000-2000 mcg.
The "standard" dose is 1000-2000 mcg per week, since is ...
There are many sources of calcium that come from vegan sources. Soy (soy milk and tofu), oranges, nuts, seeds, leafy greens, and beans all contain good sources of calcium, for example. (1,2)
Just eat a variety of fruits, veggies, leafy greens, nuts, etc. and you'll be fine!
Animal products in general are really good sources of B12. This applies to milk and the products that are made from it and I would argue that eggs are a good source of it too, although your definition might be different.
This RDI for B12 was previously set to be 6µg but is now being changed to 2.4µg. Based on this, following can be said:
Milk is a very ...
I asked a Registered Dietitian in Canada and received this answer:
Zinc/copper balance is only a concern when taking zinc or copper mineral supplements. Just focus on getting enough zinc from whole foods and you'll be fine.
This is similar to what I found in the Cronometer blog post about nutrient ratios:
Nonetheless, it is common practice to recommend a ...