Hello Runner,

Welcome back to your weekly moment of endurance nutrition!

Happy Weekend!
How are you?

I'm fine. I traveled on Tuesday and am in Brazil enjoying time with family and friends.

I came to spend a few days here to meet my niece, spend time with family, catch up with friends, and attend a sports nutrition conference next week.
My routine has changed a bit, but so far I’ve been able to work out every day.
At work, I’m just handling the most urgent tasks and will save my studies for the days of the conference.

Today's topic is vitamins. Are some vitamins more important than others for runners? Or should the focus be on all vitamins in general? 

When people think about improving their running, they usually focus on training plans, long runs, intervals, or race-day nutrition. Vitamins (coming from a strong nutrition plan) rarely make the top of the list.

It turns out that your body can only produce energy as efficiently as the nutrients available to support the process.

Every easy run, every tempo session, every long run, and every race depends on thousands of biochemical reactions happening inside your muscles. Vitamins don't provide energy themselves, but they help your body convert the carbohydrates, fats, and proteins you eat into the energy that powers every stride.

If you're eating a varied, balanced diet, you're already doing a lot right. 

If you eat a varied diet but still train A LOT over a long period of time (for example: training for a triathlon) or travel a lot, you may need some extra help (vitamin supplements). But this has to be evaluated on a case-by-case basis.

What matters most is making sure your body has what it needs to consistently adapt, recover, and perform at its best.

Here are the vitamins that matter most for runners.

If I had to choose one group of vitamins that every runner should know about, it would be the B vitamins.

This family, including vitamins B1, B2, B3, B6, folate, and B12, is essential for energy production. They help your body convert carbohydrates, fats, and protein into ATP, the energy your muscles use during every run.

They're also involved in:

✔ Red blood cell production
✔ Oxygen transport
✔ Nervous system function
✔ Muscle contraction
✔ Recovery and training adaptation

The harder and more consistently you train, the more important it becomes to meet your daily needs.

This doesn't necessarily mean you need supplements. For most runners (amateurs), regular intake through food is enough.

You'll find B vitamins in foods such as:

When are they most important?

Their biggest impact comes from supporting your body throughout your training cycle, especially during periods of higher mileage or more demanding training. 

Vitamin D is one of the most researched vitamins in sports nutrition.

Healthy vitamin D levels support:

Many runners, especially those training indoors or living in areas with limited sunlight during winter, can develop low vitamin D levels.

Research consistently shows that correcting a deficiency can improve overall health and reduce the risk of bone stress injuries. However, taking high doses just before a race won't improve performance if your levels are already adequate.

The key is maintaining healthy vitamin D status throughout the year.

Vitamin C often gets associated with immunity, but for runners it does much more.

It helps your body:

That last point is particularly important for endurance runners, as iron plays a key role in transporting oxygen to working muscles.

Vitamin C-rich foods include:

One important note: while vitamin C is essential, current research doesn't support taking large antioxidant doses immediately after training. 

Sleep is one of the most powerful recovery tools available to runners.

No vitamin can replace good sleep habits, but adequate vitamin status does support normal sleep physiology.

Some research suggests that:

Instead of looking for a "sleep vitamin," focus on consistently meeting your daily nutrient needs alongside healthy sleep habits.

A few weeks ago, I wrote a newsletter article with tips on how to improve your sleep this summer. I mention vitamins and give examples of meals that include foods rich in them. Click here to read it.

This is one of the questions I hear most often.

The answer is surprisingly simple:

Probably not.

Vitamins don't work like caffeine or carbohydrates. They don't provide an immediate performance boost.

Their job is to support your body's normal function over weeks and months of training.

Race week is to maintain your routine.

The focus should be on:

The preparation you've done over the previous months is what supports your race-day performance.

But it all depends on the runner's context. There are many people who travel for work, eat out a lot, and continue to train for races. In some cases, taking vitamin supplements is definitely worth considering, as it will help. 

One of the biggest myths in sports nutrition is that more vitamins automatically mean better performance.

For runners who already meet their nutritional needs, taking extra vitamins hasn't consistently been shown to improve endurance performance.

Where vitamins make the biggest difference is when they prevent or correct a deficiency.

That's why my advice is always the same:

Build a strong nutritional foundation first.

A varied diet, enough total energy, quality carbohydrates, adequate protein, healthy fats, and a colourful plate will provide most runners with the vitamins they need to train consistently, recover well, and keep progressing.

Supplements can absolutely have a place, but they should fill a gap, not replace good nutrition.

Any questions or something you would like to share, drop me an email

Wishing you a great weekend and week ahead!

Here’s to health and good runs⚡️

Ana Paula Alonso