Running a marathon is no small feat—it requires months of dedicated training, proper hydration, and, most importantly, the right nutrition.

Your body needs key vitamins to sustain endurance, support muscle function, and recover efficiently.

In this easy guide, we’ll break down the top vitamins for runners, where to find them in foods, and the best supplements to enhance your performance.

The Essential Vitamins for Marathon Runners

Vitamin	Why it matters	Where to find it
Vitamin D	Supports bone health and immune function, reducing stress fractures	Fatty fish (salmon, tuna), fortified dairy, egg yolks, and sun exposure
Vitamin C	Reduces inflammation and aids muscle recovery after long runs	Oranges, strawberries, bell peppers, and broccoli
B Vitamins	Helps convert food into fuel and supports nervous system function	Whole grains, nuts, lean meats, and leafy greens
Iron	Iron is essential for oxygen transport in the blood and muscle function.	Lean meats, seafood, beans, spinach, and iron-fortified cereals
Magnesium	It helps prevent cramps and promotes faster recovery post-run.	Nuts, seeds, whole grains, spinach, and dark chocolate
Ashwagandha	Ashwagandha, an adaptogenic herb, is renowned for its ability to boost stamina, alleviate stress, and enhance endurance. Research indicates that supplementing with ashwagandha can elevate VO2 max and improve overall physical performance in athletes.	supplement in capsule or powder form

Science Behind These Nutrients

According to research from the National Institutes of Health (NIH), runners who maintain adequate levels of these vitamins experience fewer injuries, improved endurance, and faster recovery.

Additionally, a 2023 study published in the Journal of Sports Nutrition found that marathoners supplementing with vitamin D and B-complex had 8% greater endurance performance compared to those with deficiencies.

Fueling your body with the right vitamins is just as important as training.

But, you train hard, eat clean, and stay hydrated—but the truth is, even the most dialed-in diets can fall short when it comes to meeting the nutritional needs of a serious runner.

Supplements fill those critical gaps, giving your body what it truly needs to perform better, recover faster, and stay injury-free.

Ready to optimize your nutrition? Check out our recommended supplements here:

Prioritize nutrient-rich foods, supplement smartly, and ensure your body is fully equipped to cross that finish line strong.

Don’t leave your finish line success up to chance—fuel smart, supplement smarter.