Plant-based diets have quickly become the norm for many of us, but while removing animal products from our diets is particularly good for the environment, it can leave us with a challenge when it comes to getting enough vitamin B12 as this vitamin is not found in plant-based foods.
Vitamin B12 naturally occurs in most animal products, including fish, meat, poultry, eggs and milk, and performs multiple key functions in the body. It is essential for red blood cell formation (whose job it is to carry oxygen), keeping the nervous system healthy, and also affects our energy, endurance, cognition and memory.
Vitamin B12 also:
- Helps fight depression
- Protects against cardiovascular disease
- Protects against eye disease and disorders
- Has a protective effect on DNA
- Protects against neural tube defects in pregnancy
- Plays a vital role in the the production of serotonin
How much vitamin B12 do we need?
Fortunately, compared to other vitamins, B12 is only required in small amounts- an adult’s recommended intake is between 1.5 and 2.4 micrograms per day, rising for women who are pregnant or breastfeeding. Also, we can store substantial amounts of the vitamin in the liver for a period of around two to four years until it is needed and can be used in the body. So if you are a flexitarian- a vegetarian who regularly consumes dairy products, or have only recently undergone a change in diet, B12 deficiency poses a very low risk.
Who is at risk of vitamin B12 deficiency?
As vitamin B12 must be broken down by stomach acid before it is absorbed, this risk rises slightly for the over 50s, as conditions which decrease stomach acid become more common at this age. This is because the same cells that produce stomach acid also produce a protein called intrinsic factor that helps your intestines absorb vitamin B12. Consequently, low intrinsic factor equals low B12. Not only can age affect low stomach acid/ intrinsic factor, but chronic stress, deficiencies and diet can too.
If you consume a purely plant-based diet, it’s important to ensure that you absorb vitamin B12 by regularly eating fortified foods such as breakfast cereals, bread, certain yeast and soy-based products, as well as some plant milks. These are generally reliable sources of vitamin B12 and can be incorporated easily into any diet.
What does a B12 deficiency look like?
Unfortunately, diagnosing a vitamin B12 deficiency can be a bit tricky as symptoms are varied and tend to develop very gradually. That said however, there are signs you can look out for that indicate something might be amiss:
Everyday activities like climbing stairs or cleaning leave you feeling exhausted. You may even experience heart palpitations and shortness of breath. This may be due to the heart needing to work harder because of the reduced number of red blood cells in the body.
A vitamin B12 deficiency can cause difficulty thinking, reasoning and memory loss, which could be due to low levels of oxygen in the brain. There is some research to suggest a link with low levels of vitamin B12 and an increased risk of Alzheimer’s disease or dementia. If you do experience these issues, it’s best to consult with your doctor.
Skin is pale or yellow
Similar to other anemias, skin can look pale or yellow (jaundice). This develops when the body breaks down red blood cells more quickly, causing the liver to release bilirubin. Bilirubin is a brownish substance that gives the skin the yellowish tone that is characteristic of jaundice. This type of B12 deficiency is usually seen in individuals with megaloblastic or pernicious anemia, which has an autoimmune component.
Although more research is needed, a recent study into preventing onset and improving prognosis of depression, found a link to vitamin B12 deficiency and changes in mood. This could be because B12 is involved in the synthesis of brain chemicals, in particular the mood-boosting chemicals known as serotonin and dopamine.
Numbness or tingling in your hands or feet
Vitamin B12 plays a role in the nervous system by supporting myelin sheaths that protect the nerves and transmit signals. Nerve problems like numbness or a tingling “pins and needles” sensation, muscle weakness, or joint pain can all be signs of a vitamin B12 deficiency.
Disturbed vision or mouth ulcers
Although more likely in long-term deficiency, blurry or double vision, sensitivity to light, and even vision loss could be caused by a lack of vitamin B12 resulting in damage to the optic nerve. Studies have also shown that a swollen and inflamed tongue that has long straight lesions on it could be an early sign of a deficiency.
Tips to get your B12
1. For vegans, aim to incorporate foods fortified with vitamin B12 into your diet two to three times per day. Great sources of B12 for vegans include marmite, almond milk, and brand flakes.
2. Seafood sources high in vitamin B12 include clams and oily fish such as sardines, salmon and tuna.
3. As we only need to consume relatively small amounts of vitamin B12, a standard multivitamin will often provide our recommended daily intake and boost levels of other useful vitamins too.
4. Vitamin B12 supplements are recommended for those at risk of B12 deficiency, including older adults, pregnant or breastfeeding women, anyone with intestinal problems, and those who have had stomach surgery.
5. Because B12 is poorly absorbed through the gut, make sure you supplement with a chewable tablet or spray which absorbs through the mucous membranes. Before supplementing with vitamin B12, it’s important that you see your GP so they can do testing and assess your B12 status to prescribe the right dose for you.