While the daily requirement is for B12 is low, it is absolutely essential for every human being. While clinical deficiency can cause anaemia or nervous system damage, the most common symptoms can cause irritability, lack of energy, poor memory and other psychological symptoms. Above all, and with any other medical issue, avoid “Web MD-ing” yourself and see a doctor if you suspect anything.
Who Needs B12?
Everyone. The RDI differs depending on both what country and what science beaurau you want to listen to. But it’s between 2 – 7µg per day (The NIH recommends 2.4µg per day : http://ods.od.nih.gov/factsheets/VitaminB12-HealthProfessional/). However B12 is believed to be safe and have no adverse side effects for doses above the RDI. So there is no need to carefully measure out what you need. B12 is mostly stored in the liver, with a small amount being lost each day due to secretions in the gut. However due to efficiency, your liver can store up to five years worth of B12. Because of this, you may not notice B12 deficiency until quite some time after going vegan (If at all!)
Omnivore Sources Of B12
B12 is found in large quantities in animal products. These include meat, poultry, seafood, eggs, fish and dairy products. Because of this, it is very rare for an omnivore who regulary eats these to lack B12. Seafood such as Salmon contain over 300% of your recommended daily intake in a single 100g serving. Even a single serving of beef gives you enough of your RDI for a single day.
While B12 is sometimes said to be in plant based or non animal based products, these are usually B12 “analogues”. Usually these are claimed to be in either wheat based products or algae (Such as seaweed). Analogues are often called “psuedo vitamins” because they are not “active” and cannot be used by the body. In some cases, the consumption of inactive b12 can prevent the active b12 working properly. For now though, all you should need to know is that within the plant world, there is no sufficient B12 supply for the human body.
The most common source of B12 for vegans is fortified foods. The vitamin is added in it’s supplement form, usually from commercial bacterial sources. Examples of these fortified foods include cereals, soy products (Such as soy milk), energy bars and nutritional yeast. Yeast spreads such as “Marmite” in New Zealand also have added B12. As an example of a fortified food, Silk Unsweetened Soy Milk has 50% of your B12 RDI in a single serving.
Many vegans choose to take a B12 supplement. Usually it’s just to keep on top of things, not because they are lacking B12 fortified foods in their diet. Most B12 supplements come in the form of methylcobalamin which is easily absorbed by the body in it’s normal form. They are usually sublingual tablets that you put under your tongue and wait to dissolve. Because there is no adverse affects for over consumption of B12, the supplements are usually way over and above what your RDI is. For example, Deva B12 Supplements contain 16666% of your RDI.