Running News Daily

Feeling extra fatigued lately? There are lots of reasons why you may not have the usual pep in your step—from overtraining to underfueling to poor sleep habits that are hampering your recovery. But one less obvious factor worth considering: vitamin B12 deficiency.

Most people are not at risk for B12 deficiency, Selvi Rajagopal, M.D., M.P.H., assistant professor of medicine at The Johns Hopkins University School of Medicine, tells Runner’s World. But it’s more common than you may think, especially among seniors. An estimated 20 percent of people over age 60, and about 6 percent of people younger than that are deficient, according to research. 

To make sure you’re filled up on the vitamin, here’s what to know about its benefits, where to find it, and signs of vitamin B12 deficiency to look for, so you know when to talk to your doctor. 

What to Know About the Importance of Vitamin B12

Vitamin B12 plays an essential role in the growth and development of our nervous system tissues and blood cells, Mark Loafman, M.D., a Chicago-based family physician tells Runner’s World. It’s important for nerve signaling and brain functioning, adds Rajagopal. And it helps break down homocysteine, an amino acid that, if present in high enough amounts, can damage the heart and increase risk of dementia, heart disease, stroke, and osteoporosis, Jen Graham, M.S., R.D.N., a Tallahassee, Florida-based registered dietitian nutritionist with Top Nutrition Coaching, tells Runner’s World. 

Our bodies don’t create B12 on their own, so we need to get it from our diet. It’s typically found in animal foods—like meat, eggs, liver, seafood, and dairy products—as well as fortified cereals. 

Because animal products are a main source of this vitamin, folks who follow a strictly vegan or vegetarian diet and don’t take a B12 supplement are at “significant risk” of deficiency, Loafman says. 

Other susceptible people include those who have conditions that interfere with their ability to absorb B12 from the GI tract, including those with celiac disease (and other GI conditions, like inflammatory bowel disease), pernicious anemia (an autoimmune condition), and people who have had bariatric gastric bypass surgery, Loafman explains. 

Older adults, including those older than age 60, are also at risk of deficiency. That’s because the functioning of your gastric cells naturally declines as you age, decreasing absorption of the vitamin, Loafman adds. 

Low levels of B12 are typically detected through a blood test, Rajagopal explains, which you can request from your doctor or may otherwise be included as a part of a routine physical exam. The recommended dietary allowance for B12 ranges from 0.4 to 2.8 mcg per day and varies based on age, sex, and whether you’re pregnant or breastfeeding, according to the National Institutes of Health.

Now that you know the importance of vitamin B12 and who is most affected by deficiency, let’s dig into the signs you’re not getting enough B12—plus how to remedy low levels. 

Signs of Vitamin B12 Deficiency

Having too little vitamin B12 can cause a host of signs and symptoms. These are directly linked to your “body’s inability to keep up with the production of new blood cells and/or the maintenance and preservation of nervous tissues,” Loafman explains. 

Here’s what to watch out for:

Fatigue, weakness, and lightheadedness. B12 deficiency can lead to megaloblastic anemia, a condition where you don’t have enough red blood cells to carry oxygen to your tissues, Rajagopal says. This, in turn, can cause you to feel tired and weak, she explains. It could also hamper your exercise performance, Loafman adds. In severe cases, the lack of red blood cells can be life threatening. The good news: This type of anemia usually occurs gradually and you’d likely notice signs of it with routine blood testing before developing significant symptoms, Loafman explains.

Numbness and tingling in your limbs. These sensations are often symmetric (meaning, they happen on both sides of the body) and typically involve the legs more than the arms, says Rajagopal. It can also crop up in the fingers and toes, she adds. Numbness and tingling happens because B12 deficiency decreases your ability to maintain nervous system tissue, Loafman explains. This effect on the nervous system can also alter your gait and cause difficulty walking.

Mood changes, trouble concentrating, insomnia, irritability, and possible memory loss. When your body isn’t able to maintain its nervous system tissue, it can cause a host of neuropsychiatric symptoms and cognitive dysfunctions, Loafman explains.

Oral irritation and recurrent ulcers. The mucous membranes in your mouth and throat require rapid new cell growth to keep up with the almost constant turnover of cells, so when these areas aren’t getting the new cells they need due to B12 deficiency, your mouth can bear the brunt of it. In addition to oral irritation and frequent ulcers, you may also notice changes to your tongue, including pain, swelling, tenderness, or pigmentation changes, Rajagopal explains.

Skin changes, like rashes and changes in pigmentation. Again, this is because B12 plays a vital role in cell production, Loafman explains, so when your levels are subpar, you may notice it influences your skin health.

GI symptoms, including nausea and diarrhea. Having low levels of B12 can cause fewer red blood cells to reach your digestive tract, which in turn can trigger symptoms like nausea and diarrhea, Graham explains. In turn, feeling nauseous can lower your appetite, she adds.

Irregular heart rate. With B12 deficiency, your heart may beat faster to make up for the reduced number of red blood cells in the body, Graham says. This is your body’s way of trying to ensure enough oxygen gets circulated to all your organs and bodily systems, she explains. 

How to Know if You Need a Vitamin B12 Supplement

If you’re diagnosed with a vitamin B12 deficiency—which, as mentioned, can be determined from a blood test at your doctor’s office—then it’s wise to up your stores by taking a B12 supplement. 

Additionally, anyone who follows a vegan diet should take a B12 supplement to prevent or correct mild deficiencies that may already be developing, Loafman says. He also recommends supplementation for people whose diets include meat or dairy, but focus more heavily on plant-based foods. Important caveat: There are a lot of health benefits associated with solely and largely plant-based diets, “so no one should feel compelled to consume animal products,” Loafman says. Instead, they should add a B12 supplement to their daily routine.

You may also benefit from a B12 supplement if you have an autoimmune disease that attacks the stomach lining or GI tract (like Crohn’s or celiac disease), have had weight-loss surgery, or are taking heartburn medications that suppress stomach acid, Graham says. Your stomach acid is what extracts B12 from the food you eat, so it’s harder for that to happen if you have less stomach acid, she explains. Older adults may also benefit from supplementation, as they are at greater risk of deficiency. 

Just keep in mind: “There is no guideline or strong evidence base to support vitamin B12 supplementation without proven deficiency,” Rajagopal says. So you may want to first get your levels checked and/or ask your doctor if supplementation is recommended for you before taking a daily pill. 

Loafman, for his part, says patients who are struggling with fatigue or other B12 deficiency symptoms often ask him to prescribe supplements or administer B12 injections, even though they don’t have any risk factors for deficiency and a blood test has confirmed their levels are in the normal range. “Often, they have been told or have heard a B12 shot will boost energy levels or help with weight loss,” Loafman explains. “I wish this were the case, but unfortunately there is no evidence of benefit or improved outcome by taking ‘extra’ B12.” 

To that end, if you’re struggling with fatigue, poor performance and/or mood-slash-cognitive concerns, it’s wise to get evaluated by your doctor, Rajagopal advises. They can confirm whether you do have B12 or other micronutrient deficiencies and help you figure out next best steps. 

How to Choose a Quality Vitamin B12 Supplement

If you’ve determined B12 supplementation is right for you, the next step is to get a high-quality product. 

In the United States, vitamins and supplements are not formally regulated, so it’s best to buy supplements that have been tested by an independent third-party company for quality, safety and purity, Graham says. 

Loafman recommends supplements certified by the United States Pharmacopeia (USP) or National Sanitation Foundation (NSF). “I would not purchase or consume an over-the-counter product that does not have this certification,” he says. You can also get a B12 prescription from your physician, which will assure you are getting a product regulated by the Food and Drug Administration, Rajagopal says. 

Look for supplements containing the natural form of B12 (methylcobalamin) instead of the synthetic (cyanocobalamin) because the latter has the potential to impair kidney function in people with borderline kidney problems, Graham says. 

In some cases, B12 injections are recommended over oral supplements. This might be at the beginning of deficiency treatment to obtain faster results, or because your body’s decreased absorption of B12 is so severe that your levels can’t be fixed with high doses of oral treatment, Loafman explains. 

The dosage for your B12 supplement, and which form is right for you, will depend on factors including your specific level of deficiency. Again, this is why it’s worthwhile to first check in with your doctor. 

Long before he became the fastest man in history, before the Olympic gold medals, world records, and global superstardom, Usain Bolt was simply a gifted teenager with extraordinary speed and limitless potential. In 2002, on the track at Kingston's National Stadium in Jamaica, the world witnessed the first chapter of a story that would forever change athletics.

At just 15 years old, Bolt lined up for the men's 200 metres at the World Junior Championships with the weight of expectation resting on young shoulders. Competing before a passionate home crowd, the Jamaican prodigy produced a performance that instantly captivated the athletics world. Crossing the finish line in 20.61 seconds, he became the youngest athlete ever to win the men's 200m title at the championships.

It was far more than a gold medal. It was the moment the world realised that a once-in-a-generation talent had arrived.

Bolt's victory in Kingston marked the beginning of one of the greatest careers in sporting history. Over the years that followed, he rewrote the record books, dominated the Olympic Games and World Championships, and transformed sprinting into a global spectacle through his breathtaking speed, infectious personality, and unrivalled confidence. His legacy continues to inspire young athletes across the globe, many of whom dream of following the same path he once began as a teenager.

This week, that dream comes alive once again as the World Athletics U20 Championships take centre stage at the iconic Hayward Field in Eugene, Oregon. The venue has already witnessed the birth of future superstars. In 2014, it was where Britain's Dina Asher-Smith and Uganda's Joshua Cheptegei captured their first global titles, launching careers that would later produce world championships, Olympic medals, and lasting legacies in athletics.

Twelve years later, another generation arrives in Eugene hoping to create its own defining moment.

Among the brightest young talents is Great Britain's Jake Odey-Jordan, the 200m bronze medallist from Lima who now owns the European U20 100m record after an astonishing 10.01-second performance. He enters the championships eager to build on his growing reputation as one of Europe's most exciting young sprinters.

The United States will look to Tate Taylor, who has already made history as the first American high school athlete to break the 20-second barrier for the 200 metres. Fresh from a Diamond League victory in a sensational 19.75 seconds, he arrives in Eugene carrying the momentum of one of the most remarkable junior seasons ever recorded.

Jamaica, the nation that introduced the world to Usain Bolt, will once again have high hopes through Shanoya Douglas. The talented sprinter has established herself as one of the championship's leading contenders after producing lifetime bests of 10.98 seconds for the 100m and 22.11 for the 200m this season.

History has repeatedly shown that the World U20 Championships are far more than a junior competition. They are often the first chapter in the careers of future Olympic champions, world record holders, and global icons. Every generation arrives with ambitious dreams, but only a select few leave having announced themselves to the world.

No one can say with certainty whether the next Usain Bolt will emerge this week. Greatness cannot be predicted, and legends are never manufactured. Yet every legendary career begins with a single breakthrough performance.

For Bolt, that defining moment came in Kingston in 2002.

Now, under the famous lights of Hayward Field, another group of gifted teenagers stands ready to chase history. Somewhere among them could be the next athlete whose name will inspire the world for years to come.

"An athlete cannot run with money in his pockets. He must run with hope in his heart and dreams in his head." More than seventy years after those words were spoken, they remain among the most powerful messages ever shared in distance running. They are often quoted as simple motivation, but behind them lies a remarkable story of sacrifice, courage, conviction, and an unwavering belief that true greatness is never measured by financial reward.

Few athletes have left a legacy as enduring as Emil Zátopek. Known around the world as "The Czech Locomotive" for his relentless determination and unmistakable running style, he redefined what was possible in endurance racing. His legendary performance at the 1952 Olympic Games in Helsinki still ranks among the greatest achievements in athletics history. In the space of just nine days, he captured Olympic gold in the 5,000 meters, the 10,000 meters, and, incredibly, the marathon—a race he had never attempted before.

Yet the world in which Zátopek competed was vastly different from today's professional athletics landscape. During the 1950s, elite sport officially operated under strict amateur rules. Olympic athletes were forbidden from accepting prize money or earning a living directly from competition, although unofficial financial arrangements existed in many sports. Zátopek himself never raced for appearance fees or lucrative prize purses. Instead, he served as an officer in the Czechoslovak People's Army, receiving a military salary while representing his country. Running brought him glory, but not personal wealth.

It was within that environment that his famous words carried genuine meaning. For Zátopek, success was never driven by the promise of money. He believed the greatest performances were fueled by hope, ambition, discipline, and the courage to pursue dreams that seemed impossible. Those qualities, rather than financial incentives, formed the foundation of lasting excellence.

With the benefit of history, his words carry even greater significance. In 1968, during the Prague Spring, Zátopek openly supported democratic reforms in Czechoslovakia. When the movement was crushed, he paid a heavy personal price for standing by his principles. He was stripped of his military rank, removed from public life, and forced into years of manual labor. The man who had once stood proudly atop the Olympic podium found himself performing physically demanding jobs, far removed from the stadiums where he had inspired millions.

His story reminds us that the values he expressed were not empty words crafted for public admiration. He lived by them, even when doing so came at enormous personal cost. His belief that hope and conviction mattered more than material rewards became evident not only in the races he won, but also in the hardships he endured with remarkable dignity.

Distance running has changed dramatically since Zátopek's era. Today's elite athletes compete in a fully professional sport where prize money, sponsorship contracts, appearance fees, and endorsement deals can be worth millions. Success on the track and roads now offers opportunities that were unimaginable during the age of amateur competition. Professionalism has transformed the sport, allowing athletes to train full-time, access world-class coaching and sports science, and build financially secure careers.

Yet despite these changes, the essence of Zátopek's message has never lost its relevance.

Every elite runner naturally hopes to earn a good living from years of dedication and sacrifice. There is nothing wrong with financial success, and the rewards available today have elevated the standard of competition across the world. But history consistently shows that money alone is rarely enough to sustain greatness. The athletes whose careers endure the longest are often those driven by an inner passion to improve, to test their limits, and to chase excellence for its own sake. Financial rewards become the result of that commitment, not the reason for it.

When competition is motivated solely by wealth, its deeper purpose can fade. But when an athlete races with genuine belief, relentless determination, and an unwavering dream, extraordinary performances often follow naturally.

That is why Emil Zátopek's words continue to resonate across generations. His legacy extends far beyond Olympic medals and world records. It lives in every runner who laces up their shoes with a goal that cannot be measured in dollars, every athlete who refuses to surrender when the race becomes painful, and every competitor who understands that the greatest victories begin long before the finish line.

The economics of distance running may have evolved beyond recognition, but the heart of the sport remains unchanged. Every athlete still arrives at the starting line carrying something far more valuable than money—hope in their heart and dreams in their head. Those invisible qualities have always been, and will always remain, the true fuel of greatness.

Winning a major championship is never just about crossing the finish line first. Behind every gold medal lies a carefully crafted race plan, and Josh Kerr's unforgettable Commonwealth Games triumph in Glasgow was a perfect example of tactical brilliance meeting extraordinary finishing speed.

While the final time of 3:54.12 for the mile will be remembered as the official result, the split times reveal a much deeper story—one of patience, precision, and devastating acceleration when it mattered most.

Kerr resisted any temptation to force the pace from the gun. Instead, he settled into a controlled rhythm, allowing the opening stages to unfold naturally. His first four 100-metre segments—14.9, 15.1, 15.3 and 15.1 seconds—brought him through 400 metres in 60.4 seconds, a measured opening that conserved valuable energy while keeping him firmly in contention.

The second lap remained equally composed. Passing 500 metres in 15.3 seconds before recording splits of 15.7, 16.2 and 15.4, Kerr reached 800 metres in 2:03.0. The pace had eased, but that was exactly where the Scottish star wanted to be. Rather than chasing early speed, he was setting the stage for a decisive finish.

Everything changed after halfway.

Kerr gradually increased the tempo with smooth, controlled acceleration. His 900-metre and 1,000-metre splits of 15.2 and 14.9 seconds signalled that the race was beginning to stretch. He then surged through 1,100 metres in 14.3 seconds before covering the next 100 metres in just 13.4 seconds to reach 1,200 metres in 3:00.8.

From there, the home crowd witnessed championship running at its finest.

Instead of fading, Kerr became even stronger. He reeled off three consecutive 100-metre splits of 13.4, 13.4 and 12.8 seconds, dismantling the field with every stride. His final 100 metres were covered in a stunning 12.5 seconds, sealing an emphatic victory and sending the Glasgow crowd into celebration.

The progression of his race was remarkable. After opening with relaxed 15-second splits, Kerr transformed the closing stages into a demonstration of world-class speed endurance. His ability to accelerate continuously over the final 600 metres highlighted not only exceptional fitness but also supreme confidence in his race plan.

Championship middle-distance racing is rarely about producing the fastest possible time from the start. More often, it rewards athletes who understand when to conserve energy and when to unleash everything they have left. Kerr executed that philosophy to perfection.

His split chart paints the picture of a runner who never panicked, never wasted effort, and saved his greatest weapon for the closing stages. It was a textbook display of patience followed by relentless aggression—a combination that turned a tactical race into a memorable Commonwealth gold medal performance.

For aspiring middle-distance runners, Kerr's Glasgow masterpiece offers an important lesson: the strongest finish often belongs not to the athlete who runs hardest from the gun, but to the one who knows exactly when to make their move. On home soil, Josh Kerr timed that move to perfection, producing a performance that will stand as one of the defining moments of the championships.

At just nine years old, Oliver Smith has achieved something extraordinary—not by chasing records or medals, but by proving that determination, compassion, and consistency can create a life-changing impact.

Hailing from Wombwell, on the outskirts of Barnsley, Oliver set himself a remarkable challenge at the beginning of the year. Rather than attempting a single marathon, he decided to complete the equivalent distance of nine marathons over several months. From January 1 to April 26, the young runner covered an incredible 380 kilometres, breaking the distance into manageable daily runs suitable for a child his age.

His routine was built on dedication. Saturdays were reserved for parkrun events, Sundays for junior parkrun, while the remaining kilometres were steadily accumulated throughout the week. Averaging approximately 3.3 kilometres each day, Oliver never lost sight of the goal that inspired every step.

The challenge carried deep personal meaning. Last summer, Oliver's father, Tom Smith, suffered a devastating health setback after losing most of the vision in one eye. Medical examinations revealed a 4-centimetre meningioma wrapped around his optic nerve, leading to a complex 12-hour operation at the Royal Hallamshire Hospital in Sheffield.

Throughout the family's difficult journey, The Brain Tumour Charity provided invaluable guidance, support, and reassurance. Grateful for the help his family received, Oliver decided he wanted to give back in the most meaningful way he could. He launched a fundraising campaign with an initial goal of raising £2,000 to support others facing similar challenges.

What followed exceeded everyone's expectations.

Oliver brought his incredible fundraising challenge to a memorable conclusion at the Mini London Marathon, finishing on the very same day his mother, Hannah Smith, completed her first-ever London Marathon. It was a fitting family celebration of courage, resilience, and perseverance.

By the time Oliver crossed the finish line, donations had soared beyond £16,500—more than eight times his original target. His remarkable achievement captured the hearts of supporters, demonstrating how one young boy's determination could unite an entire community behind an important cause.

For Oliver, however, the journey is far from over. Inspired by the overwhelming support and the difference his efforts have made, he has already begun working toward his next fundraising challenge.

His story serves as a powerful reminder that age is no barrier to making a meaningful difference. Sometimes, the greatest acts of courage are measured not by speed or distance, but by the willingness to take one small step after another for the benefit of others.

Oliver Smith's inspiring journey is more than a fundraising success—it is a testament to the strength of family, the power of kindness, and the extraordinary impact that can begin with the simplest decision to help.

Sometimes the smallest opportunity creates the greatest triumph, and Jamaica's Navasky Anderson proved exactly that with a stunning performance to capture the men's 800m title at the 2026 Commonwealth Games in Glasgow.

Less than 24 hours after scraping into the final by the slimmest of margins, Anderson produced the race of his life, surging to victory in 1:45.33 to complete one of the most remarkable comeback stories of the championships. His gold medal was not only a reward for exceptional talent but also for courage, determination, and unwavering belief when everything was on the line.

The journey to the top nearly ended in the semifinals. Locked in an intense battle with England's Max Burgin for the final qualification place, Anderson threw himself across the finish line in a dramatic dive, stopping the clock at 1:45.38. That desperate effort earned him the last available place in the final as the fastest non-automatic qualifier, keeping his Commonwealth dream alive by the narrowest of margins.

With another chance in his hands, the Jamaican made sure it counted.

In a fiercely contested final, Anderson displayed outstanding tactical awareness and patience throughout the opening stages before unleashing a devastating finishing kick down the home straight. His perfectly timed acceleration left the rest of the field with no answer as he crossed the finish line first, securing a memorable Commonwealth crown and one of Jamaica's standout victories of the Games.

Australia's Luke Boyes delivered an impressive performance to claim the silver medal in 1:45.93, while Kenya's Wyclife Kinyamal battled strongly to take bronze in 1:46.12 after another highly competitive championship race.

Anderson's unforgettable triumph will be remembered as one of the defining moments of Glasgow 2026—a powerful reminder that championships are not always won by the fastest qualifier, but often by the athlete who refuses to surrender. From a fearless dive that kept his hopes alive to a brilliant gold-medal performance less than a day later, the Jamaican wrote one of the most inspiring chapters of these Commonwealth Games.

Men's 800m Final Results

1. Navasky Anderson (Jamaica) — 1:45.33

2. Luke Boyes (Australia) — 1:45.93

3. Wyclife Kinyamal (Kenya) — 1:46.12

Navasky Anderson arrived in the final as the last man to qualify, but he left Glasgow as the Commonwealth champion—a remarkable transformation that perfectly captures the unpredictable beauty of championship athletics.