With many people pledging to cut down on meat as part of a healthier lifestyle, we explain the importance of the often misunderstood vitamin B12.
Meat Free Mondays and other high-profile campaigns to get us to cut down on the amount of animal protein we eat are aimed at improving our health.
It seems they are working, with 600,000 Britons now vegan, three million vegetarian, and almost three in ten describing themselves as meat-reducers.
However, taking meat and dairy out of our diet – particularly for those aged 50-plus – could actually do more harm than good, if care is not taken to maintain the all-important vitamin B12 levels, say experts.
Unlike vitamins C and D, the celebrities of the micronutrient world, few people other than vegans – at highest risk of a deficiency because it is not found in vegetables and fruit – will be familiar with B12. Yet the vitamin is crucial for healthy blood, and to keep the brain and nervous system functioning normally.
Without enough, we can suffer a range of symptoms, from anaemia (including tiredness, a lack of energy, breathlessness and pale skin), muscle weakness and tingling sensations, right through to more serious effects such as a decline in cognitive abilities.
Low levels of vitamin B12 may also affect mental health, studies have found, leading to problems with memory and judgement and, in some cases, depression. Left unchecked over several years, it can cause some serious and also irreversible damage to the nervous system.
It is important to know then that we cannot make B12 ourselves and that most of us absorb it from eating animal-derived food and drink. It is also a vitamin that we are more likely to be deficient in as we become older, with five per cent of those aged 65-plus having a lower than recommended level, and ten per cent over 70 with a shortfall.
The problem is that, as we age, we become less efficient at absorbing vitamin B12. Estimates about how widespread deficiency is in the older population are conservative, warns Dr Dominic Harrington, chief scientific officer at Viapath Nutris, a part-NHS-funded organisation specialising in state-of-the-art tests to analyse blood for vitamin deficiencies.
“People certainly need to be aware that from the beginning of their 50s the likelihood of them having a B12 deficiency starts to increase, and this only heightens the older they get as gastric absorption can become more difficult,” he says. “It is usually a gradual progressive problem.
“After veganism, ageing becomes the biggest likely contributor to becoming B12 deficient as you increasingly lose the acidity of the stomach, which is an early step of absorption of the vitamin.” Other at-risk groups, he says, include those with Crohn’s disease and pernicious anaemia, as well as people who have had surgery to their stomach or small intestine.
As well as taking meat, fish, poultry, eggs and dairy out of the diet, the risk also increases with certain drugs, including those used for treating acid reflux and heartburn.
“It acts as a double whammy”, says Dr Harrington.“Older patients finding it more difficult to absorb vitamin B12 then take a pharmaceutical which exacerbates the problem. And then with a restricted diet thrown into the mix as well, you can see why some people have problems.”
Although risk of a deficiency heightens with age, most people, regardless of how old they are, will get all of the vitamin B12 they need if they are eating animal products as part of a healthy, balanced diet, says the British Nutrition Foundation.
However, those following a vegan or vegetarian diet should be careful to make sure they get all they need by eating vitamin B12 fortified foods and/or taking a daily supplement, it adds.
If vegans eat two to three sources a day of fortified food – such as cereals, yeast flakes or plant milk – they should be getting sufficient B12, adds Rachel White, dietitian at Guy’s and St Thomas’ NHS Foundation Trust.
“However, if they aren’t managing this, we would recommend a supplement,” she says.
There are other things to consider too, says Heather Russell, a dietitian at the Vegan Society, including the fact that a daily supplement needs to contain at least ten micrograms, whereas a weekly supplement should provide at least 2000 micrograms.
Also, she says, vegans relying on fortified foods should aim for at least three micrograms of B12 a day, spread across two meals or more. For example, you could make porridge using 200ml of fortified plant milk and add a tablespoon of fortified nutritional yeast flakes to your dinner.
It is easy to see why there is a lot of confusion around vitamin B12, says Dr Harrington: “Even the Health Secretary, Matt Hancock, was quoted recently saying that eating broccoli will boost our B12. He was wrong. Like humans, plants and trees don’t produce it.”
Thankfully, though, once diagnosed with a blood test, vitamin B12 deficiency is a rectifiable problem.
“It’s usually something which is completely reversible if detected promptly. You can take supplements if you need them, or modify your diet and then re-test in a month or two to see if changes to your lifestyle have corrected things,” says Dr Harrington.
“If you are found to have pernicious anaemia, your GP will prescribe life-long vitamin B12 injections.”
“It mustn’t be neglected, though. We have an ageing population and what is important is increasing the number of healthy years that we live.”
Beyond any element of doubt
The only way to check you are getting the right level of vitamin B12 is to have a blood test, but even then many offered on the NHS give misleading results, says Viapath Nutris.
It offers a next-day turnaround £40 postal test, which measures active B12 in the blood that the body can use.
“Many alternatives measure how much vitamin B12 is in the blood and don’t take into account that only a quarter of it is any use,” says its chief scientific officer Dr Dominic Harrington. “That means some results are little better than flipping a coin in confirming a deficiency.”
Taking matters into hand
When it comes to vitamin B12 intake, the recommendation currently in the UK is the same for older people who are enjoying an unrestricted diet as the rest of the population.
The advice is that people ensure they regularly include the best food sources of vitamin B12 in their diet, including eggs, milk, cheese, dairy products, meat, fish, shellfish and poultry, and also fortified food such as breakfast cereals, says Rachel White, dietitian at Guy’s and St Thomas’ NHS Foundation Trust.
Other sources of B12 include yeast extract, soya milk, yoghurt and desserts as well as certain brands of rice and oat drinks.
If you are not eating these foods regularly – two to three portions, equating to 1.5 micrograms a day, she says – then speak to your GP about getting tested for deficiencies. Alternatively, a dietitian can recommend testing after a dietary assessment reveals a low intake.
“It is important to note that we would not recommend supplementing diet unless B12 deficiency has been diagnosed,” she adds.
(Article source: Choice)
