Everything you need to know about vitamin B12
There are many myths and false ideas about vitamin B12, and I've found it to be a common reason as to why some people believe an entirely plant based diet isn't natural for human beings, as it's only found in animal products. Being vegan, vitamin B12 is something you need to think about in order to prevent a deficiency in this essential nutrient but it in no way means that a vegan diet is 'unnatural'. Let me explain:
Vitamin B12 is actually produced by bacteria found in the soil. The reason animal products also contain the vitamin is because animals consume soil along with their food, and with it the B12 producing bacteria, which continue producing the nutrient in their guts. Animal flesh and other animal products contain the nutrients eaten by those animals, therefore also contain B12. In times where our society wasn't as hygienic and industrialised as today, humans would have also obtained B12 through eating organically grown plants which still had soil remnants on them. But today, with our over-use of pesticides and modern sanitation (i.e. washing and cleaning all our produce free of all this bacteria containing dirt), this just isn't the case anymore.
Vitamin B12 is crucial for many functions of the body, including the synthesis of DNA, protection of nerve cells and utilisation of carbohydrates for energy. Deficiencies can cause a number of health problems, such as anemia and mood disorders, and can possibly lead to irreversible nerve damage. Other symptoms can include depression, shortness of breath, pale skin, difficulty concentrating, fatigue, weakness and tingling of the fingers and toes. As you can see, B12 deficiencies are pretty serious. For the development of babies in pregnant women who are B12 deficient, a lack of this important nutrient can be even more harmful.
Taking a vitamin B12 supplement is almost essential if you follow an entirely plant based or vegan diet. Some foods are fortified with B12 (such as nutritional yeast, soy milk and some vegan meat alternatives), which can be enough if you consume enough of these foods on a daily basis, but this can be hard to gauge and rely on.
Some plant foods have also been said to naturally contain B12, such as mushrooms, but this is such a small amount that you would need to eat huge servings of them to get anywhere near enough the recommended daily intake. Other sources, such as spirulina, also contain biologically inactive forms of B12 which can't be effectively used by humans.
B12 can be stored in the liver for up to 2-5 years, so deficiencies usually take a long time to develop, even after not consuming the nutrient for a number of years. However, there have been cases of people developing B12 deficiencies after just a few months of switching to a vegan diet, so I would definitely recommend supplementing as soon as you make the decisions to go vegan.
I thought I'd also mention that B12 deficiency isn't a problem exclusive to vegans. In fact, many omnivores are also deficient or low in this nutrient, despite eating animal products! Elderly people or those taking medications which lower acid production of the stomach, should also consider supplementing B12 as absorption rates will be much lower. In fact, the US government recommends that ALL people over the age of 50 take a B12 supplement.
Most B12 supplements are vegan, just make sure they don't contain any lactose or are coated in a gelatine capsule! If you aren't already B12 deficient, then a supplement (or fortified foods) containing at least 250mcg of cyanocobalamin-containing B12 per day is recommended. You could also choose to take a higher dosage less frequently instead, such as 2000mcg once per week! Vitamin B12 supplements are usually in the form of chewable tablets, capsules or sprays. If you are unsure, or would like help in choosing a supplement, I would go in to your local health food store and ask for their recommendation.
If you think you might be low in B12, as well as to just check that your levels are all okay, I would recommend getting a blood test every 6 months.
Hopefully this post has been helpful in explaining the facts on B12, and if you have any questions please don't hesitate to ask away!
Gilsing, AM, Crowe, FL, Lloyd-Wright, Z, Sanders, TA, Appleby, PN, Allen, NE & Key, TJ 2010, 'Serum concentrations of vitamin B12 and folate in British male omnivores, vegetarians and vegans: results from a cross-sectional analysis of the EPIC-Oxford cohort study', European Journal of Clinical Nutrition, vol. 64, no. 9, pp. 933-939.
Vegan Australia 2016, What every vegan should know about B12.
Physicians Committee for Responsible Medicine 2016, Don't Vegetarians Have Trouble Getting Enough B12?.
Physicians Committee for Responsible Medicine, What Supplements Should I Take?
National Health and Medical Research Council 2014, Vitamin B12.