How to keep your knees healthy for life

Our knees are among the body’s most important joints, yet often the most neglected.

A little effort today can prevent pain, stiffness, and injury later in life. Here are the key facts and exercises for stronger, healthier knees.

Understand why your knees take such a beating

Research shows that even during a simple walk, the force on your knees equals one and a half times your body weight.

Over time, this strain can lead to wear and discomfort, especially if you have a physical job, play sports, or gain weight.

The four muscle groups that protect your knees

The knees rely on four major muscle groups: the hamstrings, glutes, quadriceps, and calves.

When these muscles work together, they provide stability and absorb impact. If they weaken, more stress is placed on the joint, leading to pain.

Strength training prevents cartilage degeneration

Studies show that strengthening these muscles can prevent cartilage breakdown, delaying or even avoiding the need for knee surgery.

In early osteoarthritis, strong muscles can also ease pain and reduce pressure on the joint.

Exercise improves cartilage health

Physical activity stimulates the production of synovial fluid which is the knee’s natural lubricant.

This reduces stiffness and inflammation while helping the cartilage move smoothly and stay healthy.

Strengthening also builds bone density

Some knee exercises help strengthen the bones around the joint, lowering the risk of osteoporosis.

For older adults, this added stability can improve balance and reduce the risk of falls.

Start in your thirties

While much research focuses on older adults, studies show that even teenagers who play sports benefit from early knee strengthening.

Experts recommend starting in your thirties, when muscle mass and bone density begin to decline.

Train for 15 minutes several times a week

Orthopaedic specialists suggest spending about 15 minutes, three to four times a week, on simple at-home exercises that require no special equipment.

This small routine can make a big difference in long-term mobility.

Step-ups for stronger thighs and hamstrings

Use a stair or low step and alternate legs as you step up and down.

This strengthens the quadriceps and hamstrings, helping to reduce kneecap strain that can lead to pain and clicking sensations.

Squats for stability and balance

Bodyweight squats strengthen both the quads and glutes while improving balance.

Short sets of 15 squats every 30 minutes can boost muscle-building proteins and improve quality of life for arthritis patients.

Straight leg raises to protect the joint

Lie on your back with one leg bent and the other straight. Raise the straight leg a few inches, hold, and lower slowly.

This exercise builds quadriceps strength, protects the knee, and helps prevent workout-related injuries.

Calf raises for muscle balance

Stand with your feet shoulder-width apart, lift your heels slowly, hold for a second, and lower again.

This strengthens the calf muscles and helps maintain balance between the muscles supporting your knee.

Get up from a chair to strengthen your core

Sit down and stand up repeatedly without using your arms.

This exercise works the core muscles, which play a crucial role in knee stability. To increase difficulty, use a lower chair or try it one-legged.

Seek guidance and listen to your body

If you’re new to these exercises, consult a physiotherapist to ensure proper form. You can add weights later, but bodyweight is often enough.

Muscle soreness is normal, but joint pain signals a problem that needs medical attention.

Salt could be 'inflaming your brain', scientists discover

New research has revealed that consuming excessive amounts of salt could spark inflammation in your brain. This subsequently leads to high blood pressure, uncovering a crucial 'missing link' between the condition and salt consumption that experts have been attempting to unravel.

Led by researchers from McGill University, the study indicates that certain types of high blood pressure or hypertension actually originate in the brain rather than the kidneys, as previously thought.

This could shed light on why some forms of high blood pressure fail to respond to kidney-focused treatments. Lead researcher Masha Prager-Khoutorsky, associate professor in McGill's Department of Physiology, explained: "This is new evidence that high blood pressure can originate in the brain, opening the door for developing treatments that act on the brain.

"The brain's role in hypertension has largely been overlooked, in part because it's harder to study. But with new techniques, we're able to see these changes in action."

Featured in the journal Neuron, the research replicated human dietary habits in rats by feeding them a diet containing 2% salt. This mirrors a human diet packed with fast food and products such as bacon, instant noodles and processed cheese.

The team opted for rats rather than mice, which are typically used in such studies, because rats manage salt and water more similarly to humans. This makes the discoveries more relevant to people.

Using state-of-the-art brain imaging and lab techniques, scientists have been able to track changes in rats' brains while on a high-salt diet.

They discovered that large amounts of salt activated immune cells in a specific area of the brain. This activation led to inflammation and a surge in the release of vasopressin, a hormone crucial for kidney function, salt balance and blood pressure regulation.

The spike in vasopressin resulted in an increase in the rats' blood pressure, suggesting that hypertension could originate in the brain. The researchers now plan to investigate whether other forms of high blood pressure follow similar processes.

Salt has long been recognised as a contributor to high blood pressure, alongside other lifestyle factors such as excessive alcohol consumption, smoking or a genetic predisposition to the condition.

High blood pressure is a serious health issue, but often it doesn't present any immediate symptoms. It may only be detected when it triggers a severe medical event like a heart attack or stroke.

If left unchecked, high blood pressure can lead to complications like kidney failure, heart failure, vision problems and vascular dementia, warns the British Heart Foundation.

It's estimated that five million adults in the UK could have undiagnosed high blood pressure, meaning they're completely oblivious to their risk of these potentially fatal complications. Blood pressure checks are available at GP surgeries, pharmacies and even some workplaces.

Reducing your salt intake, which includes the hidden salt in your meals and not just the extra you sprinkle on top, can aid in lowering your blood pressure.

Cutting down on smoking and drinking, whilst upping your exercise game, can also contribute to a healthier blood pressure level.

Women’s waist-to-hip ratio linked to brain function in early menopause

A new study suggests that for women who have recently gone through menopause, having more fat stored around the midsection is associated with lower performance on certain thinking and memory tests. This research, published in Menopause, also found that this connection was not altered by the use of hormone therapy over a four-year period.

The time around menopause often involves significant biological changes for women, including a natural decline in the hormone estrogen and shifts in body composition. One common change is an increase in central adiposity, which is the accumulation of fat deep within the abdomen around the internal organs. This type of fat distribution is distinct from overall body weight and is known to be metabolically active, contributing to inflammation and reduced insulin sensitivity, which are risk factors for conditions like heart disease and diabetes.

Researchers have also been exploring how these metabolic changes might relate to brain health. The brain contains receptors for estrogen, particularly in regions responsible for higher-order cognitive processes like memory and executive function, which includes skills like planning and problem-solving.

A team of scientists from institutions across the United States, including the University of Wisconsin-Madison and the Mayo Clinic, hypothesized that the combination of declining estrogen and rising central adiposity could affect a woman’s cognitive abilities during this life stage. Their work is a secondary analysis of data from the Kronos Early Estrogen Preventive Study (KEEPS), a major clinical trial examining the effects of hormone therapy.

To investigate this relationship, the researchers analyzed data from more than 700 women between the ages of 42 and 58. All participants had gone through menopause within the previous three years and were specifically selected for being at low risk for cardiovascular disease. The women were part of a randomized trial and were assigned to one of three groups for four years: one group received estrogen in the form of an oral pill, another received estrogen through a skin patch, and a third group received a placebo.

The scientists measured central adiposity using the waist-to-hip ratio, a simple calculation made by dividing the circumference of the waist by that of the hips. A higher ratio indicates a greater concentration of fat in the abdominal area. The participants’ cognitive abilities were assessed at the beginning of the study and then again at 18, 36, and 48 months.

These assessments involved a comprehensive set of tests designed to measure four distinct areas of mental function: verbal learning and memory; auditory attention and working memory; speeded language and mental flexibility; and visual attention and executive function.

At the beginning of the study, the analysis showed a clear pattern. Women with a higher waist-to-hip ratio tended to have lower scores across all four of the cognitive domains measured. This finding established a direct association between greater central adiposity and poorer cognitive performance at a single point in time for this group of recently postmenopausal women.

When the researchers examined how these cognitive scores changed over the four years of the study, they found that a higher initial waist-to-hip ratio was linked to a decline in one specific cognitive area: visual attention and executive function. This suggests that central adiposity may have a sustained negative effect on the brain systems that support skills like focusing on visual information and organizing complex tasks. The other cognitive domains did not show a similar decline linked to waist-to-hip ratio over the study’s duration.

The study also explored whether taking hormone therapy might influence this connection between body composition and brain function. The results indicated that it did not. The relationship between a higher waist-to-hip ratio and cognitive performance was consistent whether the women were taking oral estrogen, transdermal estrogen, or a placebo. Hormone therapy did not appear to protect against or worsen the cognitive associations linked to central adiposity in this population.

The authors note some limitations to their work. The study participants were predominantly non-Hispanic White, well-educated, and in good cardiovascular health, which means the results may not be generalizable to all women. Additionally, the waist-to-hip ratio is an accessible but indirect measure of abdominal fat. The four-year timeframe of the study may also be too short to observe longer-term cognitive changes or potential effects of hormone therapy.

Future research could explore these relationships in more diverse populations and over longer periods. The researchers suggest that continued follow-up of these participants, as is planned in a continuation study, may help clarify the long-term connections between metabolic health and cognition after menopause. These findings add to a growing body of evidence suggesting that metabolic factors, even in otherwise healthy individuals, may play a meaningful role in brain health as women age.

“Addressing modifiable risk factors early and often is critical to maintaining optimal health and independence as women age. The metabolic and cognitive changes that commonly occur during and after the menopause transition often catch women off-guard and are more difficult to address after the diagnosis has been made. Instituting preventive lifestyle strategies before the menopause transition will result in longitudinal health gains and reduced morbidity and mortality,” said Monica Christmas, associate medical director for The Menopause Society.

New health warning for women with 'tummy fat'

A new study has revealed that women who experience an expanding waistline during middle age are at a higher risk of developing dementia. Scientists have found that excessive belly fat in middle-aged women can be a red flag for cognitive decline.

The research, published in the journal Menopause, suggests that a woman's waist size could provide vital clues about her risk of mental decline as she gets older. Medics point out that weight gain, particularly around the midriff, is common during the perimenopause and post-menopause stages.

Such weight increases, coupled with the drop in oestrogen levels typical after menopause, are associated with reduced insulin sensitivity and heightened inflammatory processes. The latest study indicates that "central adiposity" - the medical term for excessive belly fat - is also a risk factor for cognitive decline.

Health professionals highlight that visceral adipose tissue - the fat stored around various organs including the stomach, intestines, and liver - carries more health risks than overall body fat. These include diabetes, high blood pressure, cardiovascular disease, and Alzheimer's disease.

The rise in inflammatory markers due to visceral fat and falling oestrogen levels during menopause appears to be a key factor in these disease processes. This has prompted researchers to suggest that measurements of central body fat - such as the waist-to-hip ratio - could act as "early and easily recognisable" indicators of risk for both metabolic and cognitive problems, as oestrogen receptors in the brain are concentrated in areas responsible for executive function and memory, reports Bristol Live.

Earlier clinical trials examining the link between hormone therapy and cognition produced inconsistent findings, depending on participants' ages. This prompted researchers in the latest study to explore further the connection between central body fat, cognitive function, and hormone therapy use in women who had recently entered menopause.

The study included more than 700 women aged between 42 and 58 who were less than 36 months past natural menopause. Participants were split into three groups - those given oral conjugated equine oestrogen, those given transdermal estradiol, and those given a placebo.

Central body fat was assessed using waist-to-hip ratio measurements. The researchers found that women with a higher baseline waist-to-hip ratio showed worse performance across all cognitive measures, with only changes in visual attention and executive function observed over the four-year study period.

Dr Taryn James, a study co-author from the University of Wisconsin-Madison, stated: "Central adiposity was not found to moderate hormone therapy when compared with placebo cognitive domain-specific outcomes."

The researchers, based on their findings, recommend that the cognitive health effects should be examined in early postmenopausal women, even those with low cardiovascular risk statuses. Dr Monica Christmas, associate medical director for The Menopause Society, has welcomed these findings.

She said: "Addressing modifiable risk factors early and often is critical to maintaining optimal health and independence as women age. The metabolic and cognitive changes that commonly occur during and after the menopause transition often catch women off guard and are more difficult to address after the diagnosis has been made."

Furthermore, Dr Christmas added: "Instituting preventive lifestyle strategies before the menopause transition will result in longitudinal health gains and reduced morbidity and mortality."

Doctor's warning as taking common winter vitamin could cause serious health issue

A doctor has issued a warning as a popular supplement taken in the winter could cause some health problems. The expert explained that taking too much of this vitamin could be damaging to your bones.

Many people rely on supplements to ensure they get all the vitamins and minerals they need on a daily basis. While you should be able to get all you need from a healthy, balanced diet, sometimes a supplement is needed to make sure you’re not missing anything.

This is the case with vitamin D, which we get through exposure to sunlight. Therefore, the NHS recommends you take it as a supplement through the autumn and winter months as sunlight is reduced.

This vitamin helps regulate the amount of calcium and phosphate in the body, which are needed to keep bones, teeth and muscles healthy. Therefore, a lack of vitamin D can lead to bone deformities such as rickets in children, and bone pain caused by a condition called osteomalacia in adults.

However, as is the case with any supplement, it does come with some caveats. In a video uploaded to social media platform TikTok, Doctor Suraj Kukadia warned that you must not take a “high dose” of vitamin D.

Dr Kukadia, who is better known as Dr Sooj, said: “Taking a really high dose of vitamin D for a prolonged period of time can make your bones more brittle.” His warning is supported by advice from the NHS.

On its website, the health body says: “Taking too many vitamin D supplements over a long period of time can cause too much calcium to build up in the body (hypercalcaemia). This can weaken the bones and damage the kidneys and the heart.”

The recommended dose of vitamin D is 10 micrograms (mcg) - or 40 IU. If you take more than 100mcg a day, this could be “harmful”.

The NHS continues: “If you choose to take vitamin D supplements, 10 micrograms a day will be enough for most people. Do not take more than 100 micrograms (4,000 IU) of vitamin D a day as it could be harmful.

“This applies to adults, including pregnant and breastfeeding women and the elderly, and children aged 11 to 17 years.” Children aged one to 10 years should not have more than 50 micrograms (2,000 IU) a day.

Infants under 12 months should not have more than 25 micrograms (1,000 IU) a day. On top of this, some people have medical conditions that mean they may not be able to safely take as much.

“If in doubt, you should consult your doctor,” the NHS adds. “If your doctor has recommended you take a different amount of vitamin D, you should follow their advice.”

It is not possible to overdose on vitamin D through exposure to sunlight. But you should always cover up or protect your skin if you're out in the sun for long periods to reduce the risk of skin damage and skin cancer.

Certain foods are also good sources of vitamin D. These include:

• Oily fish – such as salmon, sardines, trout, herring or mackerel
• Red meat
• Egg yolks
• Fortified foods – such as some fat spreads and breakfast cereals
• Liver (avoid liver if you're pregnant – find out about foods to avoid in pregnancy)

The eight best PCOS supplements

Polycystic ovary syndrome (PCOS) is a common hormonal condition which affects the way the ovaries work. According to the NHS, around one in 10 women in the UK are believed to have polycystic ovaries, but the World Health Organisation estimates that up to 70 per cent of cases are undiagnosed – and up to half of those affected aren’t aware because they don’t have any obvious symptoms.

In fact, many women don’t realise they have PCOS until they have trouble conceiving, as it’s the most common cause of anovulatory infertility, which occurs when an egg isn’t released.

There’s no cure for PCOS, but the symptoms can be treated and improved via a combination of diet and lifestyle changes and medications, as well as supplements.

How important are supplements? Dr Sohère Roked, a GP and functional medicine and hormone doctor, says: “You can’t out-supplement a bad diet. If you’re eating a lot of junk food, then taking five supplements won’t help, but some people do find that supplements can be very useful in conjunction with their conventional treatments.”

Learn more:

• Symptoms of PCOS
• Eight best supplements for PCOS
• Are supplements enough?

Symptoms of PCOS

PCOS causes a large number of ‘cysts’ or follicles to develop on the ovaries, each of which contains an underdeveloped egg. These follicles are sometimes unable to release an egg, which means that ovulation doesn’t take place, causing irregular or absent periods.

The exact cause of PCOS is unknown, but it often runs in families and is linked to abnormal hormone levels, including high levels of the hormone insulin which controls the level of sugar in the body.

Symptoms of PCOS often develop during the late teens or early 20s, but they can come and go over time. These can include:

• Irregular or absent periods
• Difficulty getting pregnant
• Excessive hair growth on the face, chest, back or buttocks
• Weight gain
• Thinning hair or hair loss
• Acne

It’s important to note that symptoms don’t automatically stop when women reach menopause.

The best supplements for PCOS

Depending on your symptoms and your goal, there are several supplements that may help to rebalance hormones and relieve some of the symptoms associated with PCOS.

But be aware, supplements are not a miracle cure for PCOS symptoms – they should be used in conjunction with lifestyle changes and conventional treatments.

Alex Allan, a registered nutritional therapist and founder of PCOS Clinics adds: “it’s best to check with your GP or nutritionist before embarking on new supplements, and anyone looking to conceive should check their supplements with a fertility nutritionist or their healthcare provider to ensure its safe usage.”

With all that in mind, here are the PCOS supplements that our experts recommend:

1. Inositol

Also known as vitamin B8, inositol is a type of sugar that’s made in the body. It’s found in foods including nuts, grains, fruits and beans. It’s probably the best-known supplement for PCOS, and it’s usually taken as a powder which is dissolved in water to make a sweet-tasting drink.

How does it work?

Research indicates that inositol can reduce insulin resistance, improve ovarian function and help to balance hormones in women with PCOS.

Allan says: “​​Inositol can be found in various forms, but the two most common in supplements include myo-inositol and D-chiro-inositol (DCI). Inositol takes around 3-4 months to start making a difference to symptoms, and it should be taken consistently. Don’t forget that achieving good blood sugar balance by removing excess sugars and ultra-processed foods from the diet can be more effective in helping to reduce insulin production and help with PCOS symptoms.”

2. Vitamin D

The body creates vitamin D via direct sunlight on the skin, but during the dark and gloomy autumn and winter months people in the UK don’t make enough. For this reason, the NHS recommends that we should consider taking a vitamin D supplement during the autumn and winter. People who are housebound, cover their skin or have dark skin may benefit from a supplement all year round.

How does it work?

Research shows that Vitamin D can help to improve the body’s response to insulin. This, in turn, can improve the symptoms of PCOS.

Dr Louise Newson, a GP and menopause expert, says: “Studies have shown that a high proportion of women with PCOS also are deficient in vitamin D. This vitamin D deficiency may exacerbate symptoms of PCOS, such as insulin resistance, ovulatory and menstrual irregularities, fertility issues, hirsutism, obesity, depression and elevated cardiovascular disease risk factors.”

3. B vitamins

B vitamins are a group of eight essential nutrients, each of which has its own unique function. Overall they help to:

• Support the metabolism
• Boost immunity
• Support cardiovascular and hormonal health
• Regulate stress

How does it work?

There’s established evidence that B vitamins, particularly folate and B12, have a beneficial effect on fertility, and the latest research suggests that this is particularly true for women with PCOS.

Dr Roked says: “For hormone balancing in general, the B vitamins are really important. If nothing else, I recommend B vitamins to all my PCOS patients.”

4. Zinc

Zinc is an essential mineral that supports the immune system and can help to reduce inflammation, including acne – which is a common symptom of PCOS. It’s found naturally in red meat, poultry and seafood as well as tofu, pumpkin seeds and sesame seeds.

How does it work?

Studies show that women with PCOS often have low levels of zinc, and low levels are also linked to insulin resistance. Researchers believe that zinc supplementation can support the functioning of the reproductive system and improve the symptoms of PCOS.

5. Pentadecanoic acid (C15:0)

This is a saturated fatty acid that’s naturally found in dairy products such as milk and butter, beef and lamb and some fish and plants. Research indicates that our natural levels have been declining since more people have stopped consuming dairy and switched to a plant-based diet.

How does it work?

Limited early research indicates that pentadecanoic acid has anti-inflammatory properties and can help to lower glucose levels and improve insulin sensitivity.

Dr Stephanie Venn-Watson, the chief executive at Seraphina Therapeutics, says: “PCOS is tied to multiple conditions that negatively affect our metabolism, as well as heart and liver health. Importantly, mounting studies support that deficiencies in C15:0 may be driving the rise in this myriad of conditions, especially among women in their 30s and 40s.”

6. CoQ10

Coenzyme Q10 is made naturally in the body, but we produce less of it as we age – especially if we take statins, which interfere with its production. It’s found in oily fish, organ meats (offal), tofu, broccoli, nuts and seeds, but in much smaller amounts than are found in supplements.

How does it work?

The body uses CoQ10 for cell growth and maintenance, and it’s a powerful antioxidant which studies show can help to fight inflammation.

7. Chromium

This trace mineral is naturally found in orange juice, beef, grape juice, broccoli, wholewheat flour, apples and green beans. There’s no recommended daily amount, so some experts believe that you should be able to get all you need from a balanced diet.

How does it work?

Research is still inconclusive, but chromium is believed to improve the body’s sensitivity to the hormone insulin and help to keep blood sugar levels balanced. One study found that it may also help to reduce inflammation in the body.

8. Omega-3 fatty acids

These healthy fats include DHA and EPA, which are found in fish and seafood, and ALA, which is found in plants. The best food sources of omega-3 include oily fish such as mackerel, salmon, and sardines, along with nuts and seeds such as walnuts, chia seeds, and flaxseeds.

How do they work?

Known collectively as N3 fatty acids, they support heart and hormonal health, and several small studies indicate that their anti-inflammatory properties can help to relieve symptoms of PCOS.

Are taking supplements enough?

“The main drivers of PCOS, after a genetic predisposition to it, tend to be insulin resistance, inflammation and stress – and most women with PCOS have a combination of all three,” explains Allan. “Many women turn to diet and lifestyle measures to try and mitigate these drivers and get their PCOS symptoms under control, and this includes the use of supplements.”

PCOS FAQs

Is there an all-in-one PCOS supplement?

Yes, there are PCOS supplements that contain a mix of key ingredients to support your hormone health. They’re available at most pharmacies and health stores.

Can I take magnesium and inositol together?

Yes, you can take magnesium and inositol together. They’re in fact complementary supplements, meaning they work best when taken together.

What foods should I avoid with PCOS?

Refined carbohydrates, such as white bread and pasta, pastries and sugar, can aggravate PCOS symptoms. Alcohol and caffeine should also be limited as they can disrupt sleep and hormone production.

Seven signs you’re deficient in B12 and how to fix it

Fatigue and muscle weakness. Memory loss and confusion. Pins and needles. The signs of B12 deficiency are vague, wide-ranging and usually develop gradually. It’s something that tends to impacts us as we age – but young people can suffer with it too.

And new evidence suggests that, as we age, even those who are not “deficient” could be unknowingly experiencing symptoms and would benefit from a higher intake. A recent American study of 231 healthy volunteers, whose median age was 71, found that those with lower B12 levels (but still in the normal range) showed signs of neurological and cognitive decline when performing a battery of timed tests in comparison with participants with higher levels.

So what is B12 doing for us and how do we keep our levels up?

The seven vitamin B12 deficiency symptoms

“B12 is essential for a functioning nervous system, healthy red blood cell formation and DNA synthesis,” says Dr Sabine Donnai, GP and longevity doctor. “It plays a role in the conversion of protein and fat into energy, and the formation of neurotransmitters and hormones that control our brain function.” B12 is closely linked to folate (also known as B9). They play similar roles in the body and B12 is crucial for folate metabolism – a vital bodily process that allows cells to function properly – and vice versa. “It’s like your right and left arm, they need to be together,” says Donnai.

A deficiency has a very wide impact.

1. Lack of energy

“Unexplained general tiredness and fatigue, maybe breathlessness too, can be a sign of Vitamin B12 deficiency,” says Donnai. “If B12 levels are low, the red blood cells will struggle to form, which means you won’t have enough oxygen delivered to any part of your body or your organs, whether it’s kidneys, brain, heart or lungs.”

2. Strange sensations

These could include burning, numbness or pins and needles in hands, legs and feet.

“We need B12 to make the ‘myelin sheath’, the protective layer that surrounds nerve cells,” says Dr Geoff Mullan, functional medicine practitioner at Human People. That layer allows for the efficient transmission of our nerve signals. “Without it, you stop conducting so well. If it goes on for long enough, the nerve damage can be permanent.”

3. Unsteadiness on the legs...

...Or other difficulties with coordination. This damage to the nerves and spinal cord can also lead to impaired balance and unsteadiness, as well as difficulty with motor skills.

4. Memory loss

“We need B12 to make new neurotransmitters,” says Mullan. The nerve damage and brain atrophy caused by a B12 deficiency can mirror the symptoms of dementia.

5. Brain fog

Difficulty thinking and reasoning. People with a vitamin B12 deficiency will often describe being unable to focus or concentrate, and experience difficulties completing tasks. “You’ll struggle to ‘activate’, i.e. start tasks, and also ‘do’, i.e. continue tasks,” says Mullan, “as all your mental and physical systems are struggling.”

6. Depression, agitation, anxiety and mood swings

“B12 is important in the formation of serotonin, which helps regulate mood, sleep and appetite,” says Mullan. It’s also involved in the production of dopamine and norepinephrine, other neurotransmitters that play a key role in mood.

7. Poor oral health

Recurrent mouth ulcers, painful cracks at the corners of the mouth and a sore, inflamed tongue. “In serious cases, the tongue almost becomes smooth and glossy like the inside of your cheeks, where usually the tongue should be rough,” says Donnai. (This is called “glossitis” and is probably caused by lack of oxygen and nutrients reaching the tongue.)

How to diagnose a B12 deficiency

It’s easy to test your B12 level through your GP or pharmacy – you can buy at-home tests too. “If you are going to use the at-home tests, make sure they have the CE mark,” says Donnai. One problem with at-home finger-prick tests is that, if not done properly, you can squeeze out serum, dilute the result and get an inaccurate reading. Any results should be taken to the doctor. Understanding whether you have a deficiency is more complicated than a single number, says Donnai. “We usually conduct tests that won’t be done in isolation. It will require measuring haemoglobin levels and red blood cells too.”

How to treat a B12 deficiency

Injection

The fastest way to correct a serious deficiency is through a course of B12 injections called hydroxocobalamin, typically given every other day over a two-week period.

Nasal spray

This is an option for people who don’t like injections, again bypassing the digestive system and delivering B12 directly to the bloodstream through the nasal lining.

Tablet

“For most people whose B12 deficiency is dietary-related, a high strength tablet works just as well as injections and they are a lot less expensive,

What causes B12 deficiency?

Diet

“A vegan diet is probably the biggest cause,” says Donnai. “A B12 deficiency is one of the biggest problems a vegan can face.” B12 is found mainly in animal products – meat, fish and dairy. (Dairy is important, even if you eat fish and meat, as it makes B12 more “bio-available”.) However, high-meat, low-veg diets can also be a problem.

Low stomach acid

People who are on proton pump inhibitors to reduce acid in their stomach – which is 10 per cent of the population – are at risk of B12 deficiency.

Coeliac disease

B12 deficiency is common in cases of coeliac disease, especially when untreated. The damage caused by coeliac disease to the small intestine can prevent the absorption of nutrients. Other conditions that can cause B12 deficiency include Crohn’s disease and chronic pancreatitis.

Age

Vitamin B12 deficiency becomes more common as we age, affecting around one in 10 people aged 75 or over and one in 20 people aged over 65.

Alcohol

Alcohol affects B12 levels in many ways. It decreases stomach acid which we need to release B12 from food, and also irritates the lining of the stomach and intestines, leading to gastritis which also reduces absorption.

Pernicious anaemia

Pernicious anaemia is an autoimmune disease which prevents the absorption of B12. When B12 is released from food, it binds on to a transporter called intrinsic factor, which then transports the B12 through the small intestine where it will be absorbed.

What foods are highest in B12?

“For B12, it’s animal products – meat, fish and dairy. If you’re a vegan, there is fortified nutritional yeast. Folate-rich foods are leafy green vegetables, broccoli, peas, citrus fruits, chickpeas and kidney beans.” Marmite is another vegetarian source of B12, although with a very high salt content. One 8g serving provides 76 per cent of the recommended B12 daily intake.

How long does it take to recover from vitamin B12 deficiency?

“It depends how low and serious the deficiency is,” says Donnai. “If you’ve been feeling fatigued and are just below the norm, you’ll be fine after a week. If it’s a significant deficiency where your nervous system is affected, it might take months to get back to normal.” Vitamin B12 is water soluble so leftover amounts will leave the body through urine and there is little risk of “over-dosing”.