Do Ultrarunners *Really* Need Vitamin and Mineral Supplements?
by Sunny Blende, MS
No! Well, maybe. Well, sometimes. This has to be one of the more confusing and ongoing issues for all endurance athletes, ultrarunners in particular. We are bombarded daily with advertisements, articles, friends and doctor recommendations and so on even though the vast majority of ultrarunners receive the RDA (Recommended Daily Allowance) of most vitamins and minerals in their daily diet. Even so, most of these runners, as well as most athletes in general, believe vitamin and mineral supplements are necessary for training success and studies show that most consume these supplements either as nutritional insurance or in hopes of improving performance. At the same time, supplement manufacturers have targeted the physically active individual through advertising, including older athletes, implying they have a need for more of these nutrient supplements and that by consuming these supplements, they will enhance their athletic performance. What’s the truth? Will these substances really help athletes, particularly ultra-athletes?
The short answer to this question is “Think food first.” The vitamin and mineral needs of athletes have always been a topic of discussion and, in recent years, have particularly centered on antioxidant vitamins for ultra endurance athletes, and iron and calcium for all athletes. Aerobic exercise induces oxidative stress in the body and increases the production of free radicals. These free radicals are chemical substances that contain a lone, unpaired electron and are very unstable, causing cellular damage by oxidative processes; usually to cell membranes, DNA and other molecules. Besides chronic disease, these free radicals can cause muscle tissue damage and muscle soreness. The body has two basic defenses for dealing with this carnage: the naturally formed, free radical-scavenging enzymes produced in cells, and the so-called “antioxidant vitamins” – Vitamins E, C and beta-carotene (a precursor of vitamin A found in plants).
Minerals, on the other hand, serve some basic functions of nutrients for the human body. First, many minerals serve as building blocks for body tissues such as calcium in bones and iron in hemoglobin, which is needed for oxygen transport during aerobic ultrarunning or other endurance exercise. And second, minerals are involved in metabolic regulation of many of our body’s processes. The only basic function minerals do not do, is provide a source of caloric energy. However, guess what? Which two minerals are the majority of Americans somewhat deficient in? You guessed it – calcium and iron.
Most research with antioxidant vitamins has been focused on prevention of muscle tissue damage and soreness. Eccentric exercise, such as that which the quadriceps incur when running downhill, may cause mechanical soreness that can overpower the body’s antioxidant system and theoretically, more antioxidants could help with deterrence of that soreness. Training running downhill will increase the ultrarunner’s natural enzymes, but consuming antioxidants has also been shown to reduce markers for muscle tissue damage in many studies. These include creatine kinase (CK) and lactic acid dehydrogenase… found in many ultrarunners at the end of a 100-mile run.
There may be some other good reasons for athletes to take antioxidant vitamins, but not all of them apply to endurance athletes. Those athletes involved in certain types of weight-control sports such as gymnastics, ballet and wrestling, may need supplementation due to very low-calorie diets that do not include enough vitamins to support training. Those athletes who have a poor diet or a diet heavy in processed foods where the vitamins have been removed, may also need more vitamins. Finally, because older athletes may be more susceptible to oxidative stress during endurance exercise due to the decline with age in optimal functioning of free radical-scavenging enzymes, antioxidants may be helpful.
Vitamin E has been shown to have a beneficial effect on VO2 max, reduced blood lactic acid during submaximal exercise and increased aerobic endurance at altitudes of 5,000 and 15,000 feet. This improved lactate threshold could be applicable to ultrarunners training and racing at altitude.
Even though the research is not all positive for improving athletic performance, decreasing recovery time or minimizing injury time with supplementation, the use of antioxidant vitamins can provide insurance against a suboptimal diet or the heavy training of an ultrarunner and can help limit the effects of oxidative stress on his or her body. There are no clear guidelines specifying types and dosages of specific vitamins and most experts still recommend obtaining antioxidant vitamins naturally from food. Increasing fruits and vegetables primarily, and whole grains next, will enable ultrarunners to ingest the beneficial amounts of beta-carotene (10-30 milligrams) and vitamin C (250-1,000 milligrams), but it may be difficult to ingest 100-200 IU of vitamin E through natural dietary sources. For this benefit, over-the-counter 100 or 200 IU supplement capsules are inexpensive and easy to obtain. Vitamin E comes in two forms – dalpha- tocopherol (natural form) and dl-alphatocoperol (synthetic form). The natural form is almost twice as absorbable as the synthetic form, so you need to take 40-50 percent of the synthetic form.
What should an individual take if he or she wants to take a supplement?
It is difficult to exceed the UL (Upper Limit - the highest level of intake that poses no health risk) for any given vitamin by eating natural, wholesome foods. Remember, if the vitamin content in the body is adequate, excessive vitamin intake serves no useful purpose and may even be harmful. If you want to take a supplement, the inexpensive house brands of major drug stores and warehouse stores is fine. But rather than take individual vitamins, which can lead to toxic doses and often begin to function like drugs versus nutrients, most medical authorities recommend a simple, balanced multi-vitamin with 50-100 percent of the RDA. The one exception is the athlete training for, or at, altitude, and then the recommended dosage is 100-200 IU of vitamin E.
A basic principle of mineral nutrition is the “key nutrient” theory. If you eat natural foods that are rich in calcium and iron and provide the RDA for these minerals, you should receive adequate amounts of the other major and trace minerals at the same time. Foods bring many nutrients in combination and the foods that contain calcium and iron, also contain many of the other minerals. Some of these foods include dairy products, lean meats, beans and many dark green leafy vegetables. Even whole wheat bread and potatoes (with the skin), staples of the ultrarunner’s diet, contain calcium and iron as well as many other minerals. Because these two minerals are key, a little more information may be helpful.
Calcium’s main function is giving strength to our bones, and indeed, that’s where 99 percent of our calcium is located. The other one percent is involved in all types of muscle contraction…a must for an ultrarunner! Calcium balance is important for health as well as sports performance, but national surveys show that Americans, especially females, are not obtaining adequate calcium in their diet. And the major factor underlying calcium deficiency is inadequate intake - not absorption problems or transporting problems. Because ultrarunners are eating more calories to support their increased exercise, this may not apply, but other factors, such as calcium loss in sweat, still make it necessary to be sure to include plenty of high calcium foods in your diet.
Some nutrients in food may influence the absorption or excretion of calcium. The Vitamin D and lactose in milk facilitate absorption and make dairy foods an excellent source of calcium. Phytates in beans and oxalates in spinach decrease absorption, as does dietary fiber. Excess sodium increases calcium excretion, as do high intakes of coffee, and alcohol.
The major function of iron in the body is the formation of compounds essential to transporting and utilizing oxygen – mostly hemoglobin, a compound found in the red blood cell (RBC) – a necessity for the ultrarunner, especially one running in the higher altitudes. Iron deficiency occurs in stages, with the first stage involving depletion of the bone marrow and some serum (blood) iron. The second stage further depletes the serum iron as well as begins to deplete the iron in the hemoglobin. The third stage is iron deficiency anemia and includes decreased hemoglobin with accompanying symptoms of tiredness, low energy and an inability to regulate temperature in a cold environment. It is this stage that impairs muscular performance and strongly inhibits performance in ultrarunning. It is interesting to note that research shows no performance benefit through iron supplementation in athletes that are iron deficient, yet non-anemic. Although iron supplementation will improve iron ferritin status, without increases in hemoglobin concentration, performance is not enhanced. In other words, if your hemoglobin is normal (shown with a blood test), more iron will not help your running even if your serum ferritin level increases.
Another problem for the ultrarunner is the repeated foot contact that can contribute to hemolysis - a rupturing of red blood cells in the foot - and can lead to hematuria or the presence of hemoglobin (blood) in the urine. Prolonged running may also lead to damaged muscle cells, releasing myoglobin (the iron-containing compound in muscle tissue) into the urine with the same result of iron loss.
Iron comes in two forms and the form affects the how available it is to our cells. Heme iron is associated with hemoglobin and is only found in animal foods such as meat, chicken and fish. Non-heme iron is found in both plant and animal foods; 100 percent of the iron in plant foods and 20-70 percent of the iron in animal foods is non-heme iron. Heme iron has an intestinal absorption rate of 10-30 percent while non-heme iron has only 2-10 percent absorption rate! This makes it difficult to absorb all the iron you need from plants only…you must take in almost ten times (in micrograms) the amount you need. Calcium may impair iron absorption, as will tannins in tea and oxalates in vegetables. Vitamin C will aid absorption, but only with non-heme iron; it will do nothing for heme iron. Also, a small amount of meat will increase iron absorbed from beans, vegetable or grain products. (Think chili with meat.)
Remember, “Think food first.” Vitamin and mineral supplements do not supply all the nutrients and phytochemicals present in foods that are important to our health. There are over 5,000 phytochemicals in plant foods and many of their functions are still unknown, so eat fresh fruits, vegetables and whole grains first, then, if you wish, take a multiple vitamin (that will include antioxidants) and mineral supplement to prevent any possible deficiencies that may slow your running performance or recovery.