OK, so you’ve decided to take the leap and ditch the meat (or at least reduce it). Your mum, girlfriend, aunt, pals all tell you you’re mad because you’re going to lose out on essential vitamins and minerals.
The one that they might hammer you most with is vitamin B12! You honestly don’t need to be that concerned if you are just reducing your meat – but if you’re considering veganism or even semi-veganism, read on.
What is it?
Vitamin B12, otherwise known as cobolamin, is the only metal containing vitamin. It is made by micro-organisms in the digestive tracts of ruminant animals and requires adequate sources of cobalt in the animal’s diet.
Like all B vitamins, B12 is water-soluble, but it can be stored in the liver where the body is able to draw down reserves as and when it’s required. The liver is capable of storing B12 for a very long time, so regular consumption of meat or dairy to keep B12 stores high is unnecessary.
It has been suggested that the micro-organisms that habituate in the human gut may also produce vitamin B12, but how much of this is absorbed and used by us hasn’t been widely studied.
What does it do?
Vitamin B12 is often known as the energy vitamin, because it’s highly associated with how much energy we feel we have.
And this may be no surprise considering B12 does enable us to release the energy from our food.
B12 is also very important for the nervous system, and that’s why a drop in vitamin B12 status can cause us to experience strange neurological symptoms.
B12 also helps breakdown fatty acids, and is important in the production of healthy red blood cells (that transport oxygen around the body).
As we age, our ability to absorb B12 drops, and so supplementing during our elderly years is often recommended to ward off cognitive decline and even heart disease.
Human’s only need a very small amount of B12 in their diet to make the best of its properties – around only 1.5mcg daily.
Moreover, B12 is stored in the liver in very large quantities, and it can take up to 5 years to exhaust.
However, there are several reasons why B12 deficiency may occur:
- Pernicious anaemia: a condition where the body doesn’t make enough intrinsic factor in the stomach to absorb B12.
- Vegan diets where all animal products are eliminated, or vegetarian diets where eggs and dairy are limited for very long periods of time.
- Medicines that restrict the acid production in the diet, such as omeprazole, lansoprazole, or neutralise stomach acids (antacids).
- Gastric bypass surgery, typically for obesity – but may also be due to cancers or ulceration in the stomach.
- Certain medical conditions such as Coeliac disease, HIV, Crohn’s disease
- Drinking too much alcohol – you don’t need to be an alcoholic for this to have an effect, just regular heavy consumption of alcohol can reduce B12 absorption in just 2 weeks!
The only way to know if you have a B12 deficiency is to have the vitamin levels tested in your blood.
Vitamin B12 deficiency is easily resolved by taking a supplement, however some people will need to have this injected directly into the blood, bypassing the stomach altogether.
Symptoms of B12 deficiency
There are a number of symptoms that could make you suspect that you have a deficiency, and some of these symptoms may also be warning signs for other conditions too – so don’t always assume that any/all of these means it’s B12!
- Shortness of breath
- Extreme fatigue/tiredness
- Unable to concentrate
- Clumsiness, problems with balance or co-ordination
- Numbness, pins and needles or tingling sensations
- Dizziness, vertigo or feeling faint
- Mood changes, loss of libido
This list is not exhaustive, others have been reported too.
Sources of vitamin B12
Clearly meat! Also eggs and dairy produce also supply B12. But there are other surprising sources of B12 too:
- Fortified foods: many foods that you might eat on a daily basis could be fortified with B12. Breakfast cereals are a typical example.
- Fish: although vegetarians and vegans don’t eat fish, pescatarians do! Yes, there is a branch of vegetarianism where only mammals and poultry are excluded, but sea life isn’t. If you’re considering reducing your meat, then a good substitute is to consume more fish.
- Marmite: and for the non-British readers – yeast extract. Whether you love it or not, products like Marmite or Vegemite are made with yeast, which produces B12.
You only need to supplement on B12 if you are sure you have a deficiency. It’s usually unnecessary to take B12 everyday.
If you take the plunge and follow a vegan diet, it will take a while before your liver depletes its stores. It’s possibly you fall off the vegan bandwagon by that time! It’s very de rigueur at the moment to be vegan!
If you are committed to a vegan lifestyle, consider fortified milk substitutes like soya milk, almond milk etc, adding yeast extract to your diet and taking supplements now and then as a top-up.
Seb is a writer and blogger of food and nutrition. He holds a bachelors and a masters degree in nutrition science, and has studied sports and exercise nutrition at postgraduate level. He specialises in plant-based nutrition and believes passionately that we can all live with a little less meat. He writes for www.veggieandspice.com and www.itsaboutnutrition.com