Wow… sometimes it takes me forever to get on here. Just as a side note I have been making it a point to write more in my personal journal, because there is so much about me that I do not feel the need to make known unto the world at large.
BUT someone asked me a questions about vitamin B12 and I have been wanting to answer it. So first here is the question:
How much B12 do we need, and how often? And in terms I can understand, which means not milligrams…If I eat an egg a day, is that enough B12 to last a day or a few days… or a glass of dairy milk a week could sustain me for how long? Am I correct that there isn’t a vegan source of B12, well not a ‘natural’ one. I realize there are fortified B12 options.
Great question. And I just realized that I do not know how to subscript the number 12! B12 is a micro-nutrient meaning we only need a little bit of it. As such, it is not really something you have to actively think about or be concerned with UNLESS you are a vegetarian, elderly, or have gastrointestinal disorders which effect your ability to absorb it. Without it you could suffer from nerve damage, loss of vision, depression, dementia, poor memory, megoblastic anemia, and lots of other nasty things.
In general it is found only in animal derived foods (which poses a problem to vegans who eat no foods of animal origin). However, fermented soy products such as tempeh may contain some vitamin B12 from bacteria, but unfortunately much of this B12 is in an inactive form… making that whole statement kind of pointless.
There is also a tiny bit of it in seaweed such a nori (Mmmmm Sushi) but it is so small that if that was your only source you would probably get Iodine toxicity from eating too much. No good.
So if you are a Vegan it is recommended that you either use products that are fortified with B12 (such as soy milk or breakfast cereal) or that you take a supplement. I have heard that if you take a supplement you would want it to be a vitamin B complex and not Vitamin B12 alone. For whatever reason they absorb better into your body when taken in combination.
IF you are a Lacto-Ovo Vegetarian (meaning you eat eggs and dairy products) this is what you are looking at for quantities (These numbers are for adults) The Recommended Dietary Allowance (RDA) is 2.4 mcg but the Dietary Value DV (as listed on Nutrition labels in percentage) is 6.0 mcg and in the book Nutritional Healing they recommend 200 – 400 mcg which is a pretty hefty difference I would say.
Luckily your body stores several years worth of B12 in the liver and and deficiency is really rare (unless you have the conditions listed above). There has not been found to be an Upper Limit to B12 meaning that you can’t really ever get too much of it.
One Egg contains 0.6 mcg. So it that were your only source and you were trying to reach the RDA you would need to eat 4 whole eggs.
It would take about two and a half cups of milk or yogurt, or a little less than three ounces of cheese a day to meet it.
If you just have one glass of milk a week, or one egg a day without taking in any fortified products you would be below the RDA and over a period of a few years could start to experience symptoms. However, many symptoms of nutritional deficiency can seem like lots of other things and are hard to pin point. You can have blood work done to have it checked but doctors don’t really call for it unless you are having megoblastic anemia symptoms.
If you eat any kind of meat, fish, liver, poultry etc you seriously have nothing to worry about (unless you fall into one of the trouble categories listed above).
Hope that answers it! Thanks for the question! Keep them coming 🙂