The Runner’s World Guide to Nutrition and Fueling: Vitamins, Nutrients, and Supplements

Creatine. Peptides. Protein maxxing. Anyone who wants to be an influencer seems to jump on social media to give advice about what supplement you can take that will revolutionize your running and overall health. If you’re savvy, you know most of it is not based on science and will eventually be just a waste of your money. It’s not that you don’t need supplements—the truth is, you might.But which supplements do you need and which ones are a waste of money when you’re a runner? In the Runner's World Guide to Nutrition and Fueling, registered dietitians Kristy Baumann and Briana Butler join host Mireille Siné to explain why you should first focus on making sure your day-to-day diet and pre- and postrace fueling are dialed in before you figure out which nutrients you may need to supplement.The bottom line is that most runners will benefit from some supplementation, but you need to take some time and advice before you just try whatever social media is trying to sell.What You’ll LearnIn The Runner’s World Guide to Nutrition and Fueling, we’ll teach you:Why you need to get bloodwork to determine your health status in regard to nutrients, and which supplements you might needWhy runners may need iron and vitamin D supplementation to support their trainingWhy you should let your doctor know you runWhat to know about certain supplements like creatine, green drinks/powders, and other trendy itemsWatch VideoGo DeeperThe first step all runners should take before considering supplements, whether they are vitamins, minerals, or something like green juices, is to get bloodwork. That’s because without a blood test, it is impossible to know what you specifically need or don’t need.All of our experts agree that without bloodwork, runners can be taking supplements that they don’t need while, at the same time, not taking supplements they might need.Here are some common deficiencies to pay attention to:Why Iron Is a Common Deficiency Among RunnersEvery time your feet strike the ground, your red blood cells break down, and that can lead to one of the common nutrient deficiencies in running: iron. Of course, women also lose iron (or ferritin) through menstruation, and vegetarian and vegan runners can also be low in iron because it is most available in meat. Being low in iron can limit how efficiently your body uses oxygen, leading to fatigue, and a higher heart rate.Adult men’s serum iron should be 75 to 150 mcg/dL.Adult women’s serum iron should be 60 to 140 mcg/dL.Even runners with the recommended levels of iron can need supplementation because, as our experts say, runners need to be on the high end of the spectrum of what is considered ideal for athletes.“Don’t guess,” says Briana Butler. “You want to get lab tests done to figure out if you’re deficient and not just take a supplement without knowing your numbers.”Why You Should Check Your Vitamin D and B LevelsAnother nutrient runners should check with a blood panel test is vitamin D, which can be in short supply during the winter, if you have dark skin (which blocks the sun’s rays), or if you live in a location with little sunshine and you’re mainly a treadmill runner. Together with calcium, vitamin D deficiencies can contribute to bone weaknesses that lead to stress fractures and other injuries.The optimal vitamin D level range is 30 to 50 ng/mL.“You have to make sure you’re putting the nutrients in through food first and then layer supplements in because in addition to the nutrients, the vitamins and minerals that you're getting from real foods, you're also getting antioxidants, fiber, carbs, protein, fats.”–Briana Butler, registered dietitianFood First, Then SupplementsIf you do find out you’re deficient in any vitamin or mineral, you should first, say our experts, try to eat more of the foods that are rich in those nutrients.Iron: liver, meat, clams, spinach and it helps to cook in cast-iron pansVitamin D: fish oil, fortified dairy or plant-based milks, and try to get sun exposureB vitamins: eggs, salmon, leafy greens, and whole grainsOf course, our dietitians also recommend working with an expert, yes, a nutritionist, to make sure you don’t go overboard and take too much of whichever nutrient in which you are deficient.The other reason it’s important to get testing is that many medications and medical illnesses can interfere with vitamin absorption, so if you find you are low in anything, working with a dietitian who understands your personal situation is the best way to make sure you get to, and remain at, the healthiest levels for you.Also, women who are pregnant or lactating need to check in with their doctors to be sure their supplementation is safe.Are Certain Supplements Worth It?Speaking of testing by third-party organizations, when you go to the store or online to buy supplements, be sure to buy products that do not make extreme promises and that state they have been certified to include the nutrients they claim to contain.Got questions about performance nutrition?Fueling can be the difference between a run that feels strong and one that falls apart.Through conversations with leading sports dietitians, nutrition experts, and coaches, the Runner’s World Guide to Nutrition and Fueling turns the science of sports nutrition into practical, runner-friendly strategies for everyday training and racing. Available exclusively to Runner’s World+ members on September 10!Donna Raskin has had a long career as a health and fitness writer and editor of books and magazine articles. A certified run coach who has practiced yoga for many years, she also loves to lift weights, dance, and go for long walks with her hound dog, Dolly.