The dangers associated with vitamin B12 deficiency and its effects on the brain were starkly demonstrated this week after a coroner said that Georgia Owen, 21, had killed herself “as a direct result” of her vegan diet. At the time of her death, the student had been suffering “delusional beliefs” caused by a B12 deficiency, the coroner found.
She had followed a vegan diet from 2016 and had not been taking her vitamin B12 supplements for at least six months. Owen had bought an “organic” B12 oral spray supplement from Canada, the dosage of which would be 1mcg once a day.
Nichola Ludlam-Raine, a specialist registered dietitian in bariatric surgery and diabesity, shares what we need to know about vitamin B12.
Nichola Ludlam-RaineCharlotte Clemie
What is vitamin B12 and how much do adults need?
Vitamin B12 is essential for making healthy red blood cells, supporting nerve function, maintaining DNA, and helping to reduce tiredness and fatigue. Adults need about 1.5mcg each day, according to the NHS.
What are the best natural sources of B12?
Rich natural sources include liver, beef, salmon, trout, sardines, shellfish, eggs and dairy foods. Fortified foods such as breakfast cereals, plant-based milks (NB: organic plant milks are not fortified) and nutritional yeast can also help, particularly for those eating little or no animal products.
How do I know if I have a deficiency?
Early symptoms can be subtle. These can include fatigue, weakness, pale skin, shortness of breath, tingling or numbness in the hands and feet, poor memory, low mood, mouth ulcers and a sore tongue. If deficiency becomes more severe, neurological symptoms can occur. It’s important to get symptoms checked with a blood test measuring “serum B12” rather than self-diagnosing. You also need to look at full blood count, folate and ferritin if symptoms are present to check for anaemia. Anaemia can be a separate issue because it presents with similar symptoms, but it can also be apparent at the same time as a vitamin B12 deficiency.
What levels mean I am deficient?
In clear-cut deficiency, levels of B12 are nearly always <145ng/l and usually <100ng/l. Patients with B12 in the borderline range (145-180ng/l) may have either early B12 deficiency or be healthy “low normal”.
What are the forms of vitamin B12 — and how much do people with a deficiency need?
Common forms include cyanocobalamin and methylcobalamin. Cyanocobalamin is the most widely studied, stable and often recommended form, while methylcobalamin is an active form that some people prefer. Vegans often need higher-dose supplements because B12 absorption is limited — for example, a daily supplement containing at least 10mcg, or a higher weekly dose (2000mcg) as advised by healthcare professionals.
People with deficiency may need much higher doses in tablet form or injections depending on the cause, so this should be guided medically (my bariatric patients have a 1mg B12 injection every three months due to loss of the intrinsic factor in the stomach which usually aids absorption). Watch out for “organic” supplements. Choose scientifically proven B12 supplements or injections.
Should all vegans supplement?
Yes, because B12 is not reliably available in unfortified plant foods, all vegans should use B12-fortified foods or take a supplement regularly. This is one nutrient that should not be left to chance on a vegan diet.
Where can vegetarians get their B12 from?
Vegetarians who consume dairy products and eggs can obtain B12 from foods such as milk, yoghurt, cheese and eggs, but intake can still vary, so some may benefit from checking their status, especially if intake is low or they have symptoms.
Eggs and dairy foods are a good natural source of vitamin B12Getty images
Are sprays better than tablets?
Some of my patients take B12 sprays in weeks 8-12 following their injection to bypass stomach absorption (after bariatric surgery for example). A spray would also be advantageous for those who are taking proton pump inhibitors (PPIs). However, in regular patients, although vitamin B12 sprays can be a convenient option, particularly for people who struggle with tablets, they’re not necessarily superior to standard oral supplements. Some sprays are marketed as being absorbed through the lining of the mouth, but the evidence suggests that oral tablets and sprays can both work well, provided that they contain an appropriate dose and are taken consistently.
How do I choose a supplement?
Go for reputable brands that do third-party testing, to ensure that what is on the label is in the product. Or don’t opt for a supplement and go for a prescribed medication for low B12 from a GP as these are highly regulated.
What affects absorption of B12 into the blood?
Long-term use of medications such as metformin (used to treat type 2 diabetes and gestational diabetes), PPIs such as omeprazole, and some antacids can reduce absorption over time. If you’re on metformin or taking long-term PPIs, I’d say there’s no harm in getting a B12 test annually.
Conditions affecting the stomach or gut, such as pernicious anaemia, coeliac disease, Crohn’s disease, gastric surgery or low stomach acid, can also impair B12 absorption, meaning some people may need higher-dose supplements or injections rather than relying on food alone. Heavy caffeine or excessive alcohol use doesn’t block absorption but can impair it.
Nichola Ludlam-Raine is the author of How Not to Eat Ultra-Processed