Common Nutrient Deficiencies in Runners

Common Nutrient Concerns in Distance Runners

By Holley Samuel MEd, RD, LD, CSSD, CPT 

Runners push their bodies hard every time they head out the door, especially in training for longer distance events such as half, full, and ultra marathons. While running is an excellent way to be active and contribute to a healthy lifestyle, it can deplete certain nutrients at a faster rate than other activities. While runners and non-runners can have some overlapping nutrient deficiencies or concerns, such as vitamin D, what is recommended to the average American population may not apply the same way to runners. Generally speaking, nutrients of concern for Americans are calcium, potassium, vitamin D, and dietary fiber, whereas nutrient concerns for runners are zinc, magnesium, iron, vitamin D, and vitamin B12.

Iron

While iron is not typically a nutrient of concern for the general sedentary population, it is a nutrient of concern for sedentary Americans who menstruate and even more so for runners who menstruate due to blood loss, inadequate intake through the diet, and the poor absorptive nature of iron containing foods and supplements. The RDA for this group is 18mg per day, however there is not an official amount recommended for athletes. Runners in particular experience hemolysis of red blood cells every time their foot strikes the ground, which can deplete iron at a faster rate than non-runners who do low impact exercise or are sedentary. It is estimated that between 20-68% of female athletes are iron deficient as opposed to about 10% of sedentary females. 

Food based sources of iron include heme rich sources from animal products, absorbed at a higher rate, such as red meat or oysters. They also include non-heme rich sources from plant based products, which are absorbed at a lesser rate, such as black beans, lentils, teff, and leafy greens. In order to correct existing deficiencies or anemias, supplemental iron may be required, but should not be taken without supervision from a qualified health care professional. Athletes looking to assess and improve their iron levels should get their ferritin levels tested in their next blood panel at their check up with their physician and/or work with a sports dietitian using a third party lab test such as InsideTracker. 

Vitamin D

Vitamin D is a nutrient concern for Americans in general and for runners. Those who live in seasonal places that experience winter may be at an increased risk for vitamin D deficiency. Since one of the main sources of vitamin D is from the sun and in the winter sun exposure on bare skin decreases, so does absorption of vitamin D from its rays. Many Americans and runners also do not get enough vitamin D from dietary sources, and runners seem to need more than the RDA for Americans which is 600IU. Vitamin D deficiencies can be linked to a whole host of health issues including seasonal depression, reduced bone density (and stress injuries in runners), decreased immune health and more.

While there is vitamin D in food sources like egg yolks, mushrooms, and salmon, many athletes do also need to supplement vitamin D. Dosages can range from 400-50,000IU though, so testing your levels and working with a qualified health care professional to determine the correct amount for you to take is vital. Taking too much vitamin D can be toxic and should be avoided while taking too little will not reduce risk of complications from deficiency.

Magnesium

Magnesium is the fourth most abundant mineral in the human body, and is heavily involved in over 300 different reactions. It is an electrolyte involved in bone structure, building muscle through protein synthesis, muscle and nerve function, and assists in blood glucose and blood pressure regulation. Many Americans are not getting enough magnesium through their diets, and runners tend to need even more magnesium than the sedentary population.

For people who menstruate or experience menopause ages nineteen and older, the RDA for magnesium is between 310-320 mg. For people who do not menstruate or go through menopause in the same age bracket, the RDA is between 400-420 mg. Athletes likely need to increase magnesium intake to meet their nutritional needs. Testing magnesium levels can be challenging, since less than 1% of magnesium is in the blood and the gold standard urine sample test is less convenient to use. Working with a sports dietitian who can assess an athlete’s daily food intake can help determine magnesium status and if supplementation or dietary adjustments are needed.

Vitamin B12

Vitamin B12 is a water soluble vitamin primarily found in animal products that is involved in red blood cell health and energy metabolism. Since runners require more energy in general and hemolyze red blood cells with foot strike impact, vitamin B12, along with other materials involved in the formation of red blood cells (like iron), is depleted at a higher rate than in non-runners. Vitamin B12 deficiencies are not common in the sedentary American population, since most Americans consume plenty of animal products and easily meet their RDA needs of 2.4mcg per day.

While runners who consume animal products may be getting enough vitamin B12, plant based athletes in particular may struggle to get enough vitamin B12 without a supplement. Vitamin B12 supplement dosages range widely, so working with a sports dietitian and testing your vitamin B12 levels via blood work are essential to determining status. While dietary interventions to increase vitamin B12 will benefit runners who consume animal products, supplementation or eating fortified plant based foods will be necessary for plant based runners.

References

  1. Current dietary guidelines. Top 10 Things You Need to Know About the Dietary Guidelines for Americans, 2020-2025 | Dietary Guidelines for Americans. (n.d.). Retrieved June 21, 2022, from http://dietaryguidelines.gov/resources/2020-2025-dietary-guidelines-online-materials/top-10-things-you-need-know-about-dietary 

  2. Alaunyte, I., Stojceska, V. & Plunkett, A. Iron and the female athlete: a review of dietary treatment methods for improving iron status and exercise performance. J Int Soc Sports Nutr 12, 38 (2015). https://doi.org/10.1186/s12970-015-0099-2

  3. Sodium and Food Sources. CDC. (n.d.). Retrieved June 21, 2022, from https://www.cdc.gov/salt/food.htm#:~:text=Americans%20consume%20an%20average%20of,mg)%20of%20sodium%20each%20day.&text=But%20the%202020%2D2025%20Dietary,of%20a%20healthy%20eating%20pattern. 

  4. Vitamin D Fact Sheet for Professionals. National Institute of Health. Updated August 17, 2021. Accessed March 2, 2022. https://ods.od.nih.gov/factsheets/VitaminD-HealthProfessional/

  5. Yoon S, Kwon O, Kim J. Vitamin D in athletes: focus on physical performance and musculoskeletal injuries. Physical Activity and Nutrition. 2021;25(2):020-025. DOI: https://doi.org/10.20463/pan.2021.0011

  6. Magnesium Fact Sheet for Health Professionals. National Institute of Health. Updated on March 1, 2022. Accessed March 27, 2022. https://ods.od.nih.gov/factsheets/Magnesium-HealthProfessional/

  7. National Institute of Health. Vitamin B12 Fact Sheet. Updated March 9, 2022. Accessed March 16, 2022.

  8. Nebl J, Schuchardt JP, Ströhle A, Wasserfurth P, et al. Micronutrient status of recreational runners with vegetarian or non-vegetarian dietary patterns. Nutrients. 2019 May 22;11(5):1146. doi: 10.3390/nu11051146. PMID: 31121930; PMCID: PMC6566694.

Holley Samuel