Should runners take vitamins, minerals or other supplements?

Whether you're training for a half marathon or preparing to conquer a full marathon, you've probably wondered whether supplements can help improve your performance, recovery, or endurance. The short answer? No, supplements aren't essential. Most runners can get all the nutrients they need from a healthy, balanced diet. However, endurance training places unique demands on the body, and some runners may benefit from targeted supplementation to support their training goals, recovery, and overall health. The key is understanding which nutrients matter most, when supplementation may be helpful, and why a food-first approach should always come first.

Why Endurance Runners Consider Supplements

Running is fundamentally different from many other forms of exercise. Half marathon and marathon training is built around endurance. As your mileage increases, so does the stress placed on your muscles, energy systems, immune function, and recovery processes. Long runs can last anywhere from 60 minutes to several hours, requiring your body to work efficiently for extended periods.

Many runners look to supplements as a way to:

• Support energy production

• Aid recovery between training sessions

• Maintain immune health

• Reduce fatigue

• Fill nutritional gaps

• Support overall performance

  
  

While supplements can play a role in certain situations, they should never replace a well-balanced diet.

Nutrition Comes Before Supplements

Before considering supplements, runners should focus on the fundamentals.

• Eating Enough Calories

  
  

One of the biggest mistakes endurance runners make is under-fuelling. Your body needs enough energy to support training, recovery, and everyday health. Runners who consistently consume too few calories often experience fatigue, slower recovery, increased injury risk, and poorer performance.

• Meeting Macronutrient Requirements

Carbohydrates are particularly important for endurance athletes because they provide the primary fuel source during running. A balanced intake of: carbohydrates for energy, protein for recovery and muscle repair and healthy fats for overall health will do far more for your running performance than most supplements ever could.

• Staying Hydrated

  
  

Hydration plays a critical role in endurance performance. During long runs, runners lose fluids through sweat, along with electrolytes such as sodium, potassium, and calcium. Maintaining proper hydration helps support performance, recovery, and overall health.

• Avoiding Nutrient Deficiencies

  
  

Even a mild deficiency in certain vitamins or minerals can impact energy levels, recovery, and training consistency.

• Considering Supplements When Necessary

  
  

Once the foundations above are in place, supplements may help address specific nutritional needs or deficiencies.

Do Runners Need a Multivitamin?

Many runners assume they should take a daily multivitamin, but this isn't always necessary. Sports nutrition experts generally agree that athletes do not require significantly more vitamins and minerals than the general population. In fact, many runners consume larger quantities of food than sedentary individuals, making it easier to meet nutritional requirements through diet alone.

If you regularly eat the following you're likely already getting most of the vitamins and minerals your body needs.:

• Fruits and vegetables

• Whole grains

• Lean proteins

• Dairy or fortified alternatives

• Healthy fats

However, a multivitamin may be beneficial for runners who:

• Follow restrictive diets

• Have limited food variety

• Are training while in a calorie deficit

• Have confirmed nutrient deficiencies

• Follow vegetarian or vegan diets

Vitamin B12 is particularly important for plant-based runners, as it is naturally found almost exclusively in animal products and plays a key role in energy production.

Focus on a healthy balanced diet before reaching for supplements

What Should You Monitor?

Although most runners can meet their nutritional needs through food, there are several nutrients that deserve special attention.

• Iron

  
  

Iron is essential for carrying oxygen around the body. Low iron levels can significantly impact endurance performance, leading to fatigue, reduced stamina, and slower recovery. Female runners and vegetarian runners are often at greater risk of iron deficiency.

• Magnesium

  
  

Magnesium supports muscle function, energy production, and recovery. While deficiency is relatively uncommon among athletes with balanced diets, it is still worth monitoring. Have a read of this post for more on magnesium.

• Vitamin B9

  
  

Vitamin B9 (Folate) contributes to energy metabolism and red blood cell production. Younger athletes may be at a higher risk of inadequate intake.

• Vitamin B12

  
  

Vitamin B12 supports energy production and nervous system function. Vegetarian and vegan runners should pay particular attention to their B12 intake.

• Vitamin D

  
  

As mentioned earlier, vitamin D remains one of the most common nutrient concerns among endurance athletes, particularly during winter in climates where a lack of sun is an issue.

• Omega-3 Fatty Acids

  
  

Omega-3 fatty acids support several areas of health that are important for runners, including heart health, brain function, vision, joint health and recovery. The body cannot produce omega-3 fats on its own, so they must come from food sources such as oily fish or supplements. If you rarely eat oily fish, an omega-3 supplement may help you meet your requirements.

• Glutamine

  
  

Glutamine is an amino acid that plays an important role in immune function. Long-duration endurance exercise can reduce glutamine levels in the muscles and bloodstream. Since intense training can temporarily place additional stress on the immune system, some runners choose to supplement with glutamine to support recovery and immune health. While research remains mixed, it continues to be a popular supplement among endurance athletes.

• L-Carnitine

L-Carnitine helps transport fatty acids into cells where they can be used to produce energy. Endurance running relies heavily on aerobic energy production, so some runners use L-carnitine supplements as part of their training routine. Although evidence on performance benefits varies, it remains one of the most commonly used endurance supplements.

Can You Take Too Many Vitamins?

Yes. More is not always better when it comes to supplementation. While many vitamins and minerals are safe when taken appropriately, excessive intake can potentially cause health issues. For example, very high doses of vitamin C have been linked to kidney stones, while excessive vitamin E intake may increase the risk of bleeding complications.

This is why supplementation should be targeted and based on actual needs rather than guesswork. If you suspect a deficiency, it's always best to consult a healthcare professional and consider appropriate testing before starting supplements.

Should Runners Take Vitamins, Minerals and Other Supplements?

Should runners take vitamins, minerals and other supplements depends on the individual. Some runners may benefit from supplementation due to:

• Nutrient deficiencies

• Dietary restrictions

• High training volumes

• Limited sun exposure

• Poor dietary quality

  
  

Others may find they can meet all of their nutritional needs through food alone. For most runners, focusing on consistent training, adequate calorie intake, quality carbohydrates, sufficient protein, hydration, sleep, and recovery will deliver far greater results than any supplement.

Summary

Half marathon and marathon runners don't automatically need supplements. A balanced diet remains the best way to obtain the nutrients required for endurance performance, recovery, and overall health. However, targeted supplements such as vitamin D, omega-3 fatty acids, electrolytes, or a multivitamin may be beneficial in certain situations, particularly when dietary gaps or deficiencies exist.

Before reaching for supplements, focus on the fundamentals: eating enough, fuelling properly, staying hydrated, and recovering well. Once those foundations are in place, supplements can help support your training, but they should never be the starting point.