Experts reveal the one vitamin deficiency that could be draining your energy
Vitamin B12, also called cobalamin, is an essential nutrient that plays a crucial role in our bodies, from red blood cell formation and DNA synthesis to nerve and brain function. It plays an important part in the upkeep of myelin, which insulates every nerve fibre, and that explains why some of us will experience pins and needles if we’re low in B12.
Regenerative and aesthetic doctor Dr Miriam Adebibe says, ‘Not only does Vitamin B12 provide energy, boost blood supply, support the nervous system and help with the production of blood cells, it should also be considered essential for our skin. The problem is that many of us are suffering from low levels of this important vitamin.’
The ‘youth vitamin’
‘I think of Vitamin B as a “youth vitamin,’”’ continues Dr Miriam. ‘It’s required by every single cell in the body to divide and multiply, which means that if your cells are deficient in B12, every cell will multiply in a deficient state and therefore produce further deficient cells.’
You will have heard a lot about B vitamins and how important they are in our diets. There are eight altogether: thiamin (B1), riboflavin (B2), niacin (B3), pantothenic acid (B5), vitamin B6, biotin (B7), folate (B9), and vitamin B12 and they all have different jobs in our bodies. ‘B12 belongs to the family of eight vital B vitamins that the human body cannot produce independently yet requires for fundamental biological functions,’ says registered nutritional therapist Julie Weston. ‘Like all essential nutrients, B12 must be obtained through diet or supplementation, making its inclusion in our nutritional intake a non-negotiable for maintaining optimal health.
‘All B vitamins are water-soluble which means they enter your bloodstream and are immediately absorbed into your tissues for use. Unused B vitamins will be excreted in the urine, hence it’s important to ensure a regular intake.’
So how does B12 differ from other B vitamins? ‘B12 is unique as it has a complex absorption process,’ says Deborah Grayson, a pharmacist and nutritional therapist who runs Digestion With Confidence (www.digestionwithconfidence.co.uk). ‘Unlike other B vitamins, B12 is only found naturally in animal products – meat, fish, dairy and eggs – so if you’re vegan or mostly plant-based, it’s much harder to get it from food alone. It also needs a substance called intrinsic factor, made in the stomach, to be absorbed properly – and that process becomes less efficient as we age or if we have certain digestive conditions.’
So, it’s not just about eating enough B12; it’s about your body being able to use it. ‘B12 is unique among vitamins because it contains a metal ion, cobalt, and it’s the only vitamin that isn’t synthesised by plants or animals but by certain bacteria,’ explains Deborah. ‘B12 also works closely with vitamin B9 (folate) to help make red blood cells and to help iron work better in the body.’
Julie adds, ‘Although B12 can be obtained from fortified foods like breakfast cereals and nutritional yeast, the absorbability can sometimes be less effective. In fact, the exact rate of absorbability depends on a person’s digestive health.’
Essential jobs
Let’s take a closer look at exactly why B12 is so important in our bodies. ‘B12 is essential for cell division, the formation of DNA, and keeping our nervous system running smoothly,’ says Deborah. ‘It's really important in producing red blood cells – without enough B12, you can develop megaloblastic anemia, where the blood cells are too large and don’t work properly. On the neurological side, B12 supports the myelin sheath that protects our nerves. That’s why deficiency can show up as tingling, numbness or even mood changes and memory issues.
‘There’s also emerging research linking low B12 levels to cognitive decline in older adults – a study published in Neurology (2011) found brain shrinkage was more pronounced in people with lower B12, even if they weren’t technically deficient. That’s significant.’
Julie adds, ‘Vitamin B12 has the most complex and largest chemical structure of all the B vitamins due to the metal ion at its core. This enables it to perform a wide range of critical functions in the body. Frequently referred to as the “energy vitamin,” vitamin B12 may help improve energy levels and support recovery from exhaustion. This is because as well as its importance in red blood cell development it also supports thyroid function and cellular energy.’
How do you know if you’re B12 deficient?
There are lots of signs that your body could be low in vitamin B12, but the main ones to look out for are fatigue (even after a good night’s sleep), tingling or numbness in extremities and neurological problems like confusion or memory loss. You may also experience gastrointestinal issues, anxiety and low mood.
Dr Miriam adds, ‘Vitamin B12 deficiency can also wreak havoc with skin, as considering that the skin cells on our faces renew every 28 days (which is faster than anywhere else your body) if you’re deficient in B12, your skin will renew in a deficient state, resulting in new skin cells that are also deficient.’
Deborah says, ‘Some people get mouth ulcers or a swollen, sore tongue (glossitis). As it progresses, neurological symptoms can set in – tingling in the hands and feet, balance issues, mood swings or even depression.’
At least 40% of us aren’t getting enough of this important vitamin
The NHS flags certain groups as more at risk: people over 65, vegans and anyone with digestive issues such as coeliac disease, Crohn’s, or those on long-term acid-reducing medications like omeprazole. ‘Pernicious anemia, an autoimmune condition, is also a key cause,’ says Deborah, ‘as it prevents you from absorbing B12 at all.’
Due to its wide range of functions within the body, symptoms of B12 deficiency are varied and not always obvious. Julie advises: ‘Consider if you’re at higher risk, e.g. if you have hypothyroidism, digestive issues, you’re vegan or vegetarian, over age 50 or if you’ve had weight loss/bariatric surgery.’
Dr Miriam says, ‘Lacking energy or feeling a little low are common signs of Vitamin B12 deficiency that are easily be attributed to other factors and at least 40% of us aren’t getting enough of this important vitamin, especially if your vegetarian or vegan, enjoy the odd evening glass of wine, if you’re overweight or approaching middle age. Not only does upping your intake of Vitamin B benefit the body – increased energy, better focus, improved mood, metabolism, and levels of anxiety, but it also helps to support healthy hair, skin, and nails.’
Plant-based problems
If you’re veggie or vegan you’re likely aware of Vitamin B supplements and making sure you get enough fortified foods already. Registered dietitian nutritionist at Vegan Wins, Jennie Norton has great insight for those on a plant-based diet:
‘When B12 absorption or intake falls, the bone marrow struggles first. People often notice tiredness, light‑headedness, a faster heartbeat and skin that looks unusually pale because the marrow is turning out large, fragile red cells that carry less oxygen.
‘Soon the nervous system joins in. Tingling in the feet and hands, a feeling of walking on cotton, poor balance when the eyes are closed, and slowed reaction time all point toward injured peripheral nerves. An American Geriatrics Society study linked low B12 status with weaker sensory and motor nerve signals, which explained slower gait and grip in older adults.
‘Cognition can slide as well. Analysis of NHANES data found that adults with low B12 combined with high unmetabolised folate scored lower on memory and processing‑speed tests. More recently, University of California‑San Francisco neurologists reported that even “normal” B12 levels might not be enough to keep white matter healthy, noting slower visual and mental processing in volunteers whose levels sat at the low end of the reference range.
‘Several everyday situations raise the risk. Strict vegan eating, chronic gastritis, Crohn disease, bariatric surgery and pernicious anemia all reduce absorption. Metformin deserves a special mention: a 2019 meta‑analysis showed it measurably lowered serum B12 and doubled deficiency risk in people with type 2 diabetes.
‘Unchecked deficiency matters because anemia limits endurance, nerve injury can become permanent, and unmetabolised homocysteine rises. A landmark review of homocysteine‑lowering trials found that adding 0.5mg B12 to folic acid cut plasma homocysteine a further 7%, a change linked to lower vascular event risk.
‘Recognising the early signs and ordering a simple serum B12 test keeps the condition easy to correct, usually with an oral 1 000µg cyanocobalamin tablet or, when absorption is poor, intramuscular shots followed by a reliable supplement plus B12‑fortified foods. In most cases energy returns within weeks and numbness recedes over months once levels rise.’
Dr Miriam adds, ‘For anyone concerned that they may be deficient, a Vitamin B12 booster is the most efficient option as you aren’t reliant on your gut to absorb it as you would with oral supplements. It’s also the most reliable way to ensure that your body is getting a dose of an effective level but it’s important to seek consultation with a doctor first as they can create a plan which may require further referral.’
How much B12 is optimal?
The NHS recommends adults get 1.5 micrograms of B12per day, however The National Institutes of Health recommend an average daily amount of 2.4 micrograms for adults. ‘Some experts argue we may need more than the NHS guidelines,’ says Deborah. ‘Particularly if absorption is an issue.’ She recommends liver, beef, sardines, tuna, eggs and dairy as the best sources of dietary B12. ‘If you’re vegan or vegetarian, fortified foods (some plant milks, cereals and nutritional yeast) are essential, but supplementation is usually needed too. Look for adenosylcobalamin or methylcobalamin in your supplements – both are effective, but methylcobalamin may be better for people with certain absorption issues.’
Dr Miriam says, ‘B12 used to be present in high levels in the soil from which we would farm food, however with modern day intensive farming, the soil quality has declined – even animals are given supplements of the vitamin.’
Supplements are a great way to access B12, and these aren’t just oral tablets or liquids but booster injections. ‘For those with diagnosed deficiency or pernicious anaemia, GPs often prescribe B12 injections, typically hydroxocobalamin every few months, to bypass the gut entirely,’ says Deborah. ‘A good resource on this is the British Dietetic Association’s factsheet on B12 – it’s very clear on food sources and supplementation.’
So, give your body a boost and make sure you’re doing all you can to top up this wonder nutrient. Try having a few more boiled eggs a week alongside a meat-inclusive diet or some fortified cereals or spreads (we particular like Marmite and Vegemite) and a good old-fashioned daily tablet such as Holland & Barrett’s High Strength Slow Release Vit B12. If you still see no improvement in symptoms or you have any concerns with your health at all, check in with your GP.
