According to the most recent CDC report on dietary and nutritional indicators in the U.S population, the most deficient micronutrients are vitamin B6, iron and vitamin D [1, 2]. Not only for the general population but also for endurance athletes, iron is one of the most essential minerals and, at the same time, one with the highest risk of deficiency [3-6].
Iron is critical to health and vitality of all bodily functions and it is paramount for optimal athletic performance. It is essential for energy metabolism, oxygen transport, and acid-base balance. In the human body, approximately 6% of iron is a component of proteins involved in respiration and energy metabolism, collagen synthesis, immune function and neurotransmission; about 25% is stored as ferritin within the circulating red blood cells. The majority however (~ 70%), is found in hemoglobin, a fundamental protein of red blood cells, which facilitates the transportation of oxygen (O2) and carbon dioxide (CO2) throughout muscles, organs and other tissues.
With low iron intake or insufficient absorption, iron depletion develops and stores are exhausted. Without addressing this issue, iron depletion may lead to iron-deficient erythropoiesis and ultimately to iron deficiency anemia. Endurance athletes and women are at an increased risk for suboptimal iron status and compromised hemoglobin function with potential negative consequences on performance due to the combination of increased iron requirements, exercise induced inflammation, and inadequate dietary intake [4, 7].
Factors that affect iron levels can be dietary, hereditary (i.e., sickle cell anemia), other diseases that cause inflammation and may compromise the immune system (e.g., inflammatory bowel diseases), carbon dioxide levels, blood pH, body temperature, hormonal imbalances and other environmental factors and stressors . Interestingly, recent literature reviews show that critically low body iron levels can cause anemia and thus limit the delivery of oxygen to exercising muscle, but tissue iron deficiency may also affect performance by, for example, hampering muscle oxidative metabolism .
Endurance athletes typically strive to control one or many of the above factors in order to improve and maximize their iron and hemoglobin levels, increase oxygen carrying capacity and elevate their performance. A few of theeasiest parameters to control for that purpose are: enhancing diet and digestion, minimizing inflammation and stress, and maximizing the immune system response. Enhancing diet and digestion involves incorporating iron-rich foods such as dark green leafy veggies (e.g., spinach, kale, broccoli), beets, lentils, cow liver or any red meat in moderation, increasing anti-inflammatory foods such as honey, olive oil, fruits/berries, nuts, green tea and fatty fish, avoiding supplements that alter the stomach pH and compromise digestion efficiency, and keeping the microbiome diverse by consuming yoghurt, kefir or other healthy fermented foods and/or probiotic/prebiotic supplements. Minimizing inflammation and stress and maximizing the immune system strength may be achieved by adequate sleep and recovery, optimal digestion, and adequate macro/micro nutrient intake to ensure proper metabolism and energetics, vitamin and hormonal levels and mental health.
Aside from dietary interventions, for athletes seeking high level performance, even if hemoglobin and iron levels are within the clinical healthy range, it may be beneficial to elevate those to the upper ranges as a preventative action in order to avoid depletion during phases of training overload and also as a supportive action to aid in optimal oxygen transfer. For example, even as little as 30 mg of Fe as ferrous sulfate improved ventilatory threshold during submaximal exercise tests in recreational endurance athletes . Randomized, placebo-controlled supplementation trials of iron-depleted female athletes have also shown that oral iron supplementation in doses of 100-mg FeSO4·d (approximately 20 mg elemental iron) improves iron status and measures of physical performance . In a recent literature meta-analysis, it was found that improved performance is reported in non-anemic iron-deficient athletes that supplemented with oral iron .
In summary, iron is an important element for the health and vitality of blood, metabolism, oxygen transportation and energy production. Iron is a crucial component of hemoglobin and without enough iron, hemoglobin’s function is impaired and the body cannot maintain healthy oxygen-carrying red blood cells. This condition may lead to fatigue and compromise mental and physical performance as well as the immune system defenses. Therefore, maintaining iron levels at the highest clinical range is beneficial, especially for endurance athletes and females that are at increased risk of low iron levels.
MultiV Pro contains 27mg of Iron (as Ferrocel amino acid chelate) as well as a unique blend of micronutrients and pro/pre-biotics that aid absorption. It is an excellent choice for maintaining strength, endurance and optimal health, and for improving performance.
- Pfeiffer, C.M., et al., The CDC’s Second National Report on Biochemical Indicators of Diet and Nutrition in the U.S. Population is a valuable tool for researchers and policy makers. J Nutr, 2013. 143(6): p. 938S-47S.
- CDC. Second National Report on Biochemical Indicators of Diet and Nutrition in the U.S. Population 2012 2012; Available from: https://www.cdc.gov/nutritionreport/index.html.
- Clenin, G., et al., Iron deficiency in sports – definition, influence on performance and therapy. Swiss Med Wkly, 2015. 145: p. w14196.
- Hinton, P.S., Iron and the endurance athlete. Appl Physiol Nutr Metab, 2014. 39(9): p. 1012-8.
- Coates, A., M. Mountjoy, and J. Burr, Incidence of Iron Deficiency and Iron Deficient Anemia in Elite Runners and Triathletes. Clin J Sport Med, 2017. 27(5): p. 493-498.
- Parks, R.B., S.J. Hetzel, and M.A. Brooks, Iron Deficiency and Anemia among Collegiate Athletes: A Retrospective Chart Review. Med Sci Sports Exerc, 2017. 49(8): p. 1711-1715.
- John Beard, B.T., Iron status and exercise. The American Journal of Clinical Nutrition, 2000. 72(2): p. 594S-597S.
- Peeling P, D.B., Goodman C, Landers G, Trinder D, Athletic induced iron deficiency: new insights into the role of inflammation, cytokines and hormones. European Journal of Applied Physiology, 2008. 103(4): p. 381-391.
- Buratti P, G.E., Rybinska I, Cairo G, Recalcati S, Recent Advances in Iron Metabolism: Relevance for Health, Exercise and Performance. Medical Science Sports & Exercise, 2015. 47(8): p. 1596-1604.
- Hinton PS, S.L., Iron supplementation maintains ventilatory threshold and improves energetic efficiency in iron-deficient nonanemic athletes. European Journal of Clinical Nutrition, 2007. 61(1).
- DM, D., Iron supplementation for female athletes: effects on iron status and performance outcomes. Current Sports Medicine Reports, 2013. 12(5): p. 349.
- Rubeor A, G.C., Manning J, White J, Does Iron Supplementation Improve Performance in Iron-Deficient Nonanemic Athletes? Sports Health, 2018. 10(5): p. 400-405.