Minerals may not be the most glamorous sports nutrition supplement, but they are very important and frequently ignored. For example, the RDA for calcium is 1,200 mg per day-an amount that is almost impossible to obtain from whole foods unless you eat a lot of dairy products. What is the typical bodybuilding diet? Egg whites, oatmeal, chicken breast, rice, vegetables (sound familiar?) I knew one bodybuilder who ate nothing but tuna and brown rice (even for breakfast). I pleaded with him to take a mineral supplement, but he didn’t think it was important. Mineral supplements cost a few cents a day and can provide valuable insurance against some major problems you really don’t want, like osteoporosis and anemia . This month I want to talk about the trace elements. These are the minerals which are required by the body in very small amounts. The body generally stores less than five grams of the trace minerals. If you eat a bal-anced diet, you probably don’t need a vita-min or mineral supplement. However, many people who do eat all of the food groups still have mineral deficiencies anyway. And to make matters worse, bodybuilders do not always eat a balanced diet. Most body-builders agree with our recommendation to avoid and dairy products because of the simple sugars found in these foods. So for most people following a strict bodybuilding diet, vitamin and mineral supplements are recommended . The following trace elements are con-sidered to be essential in human nutrition: iron, zinc, copper, iodine, magnesium, chromium, selenium, silicon, cobalt, fluo-ride, nickel, molybdenum, vanadium and arsenic (1). Iron is probably the most well studied of these, and also perhaps the one which is most commonly deficient.
As you know, most of the body’s iron is found in the red blood cells, where it is bound by hemoglobin. Hemoglobin is the protein which transports oxygen from the lungs to working tissues. Without enough iron, you can’t make enough hemoglobin and then this reduces the blood’s oxygen carrying capacity. In this condition, known as iron deficiency anemia, exercise performance is severely limited. In addition to being found in red blood cells, iron is also found in muscle cells incorporated into a protein called myoglobin. This is an oxygen bind-ing protein that helps shuttle oxygen from the blood to the respiratory center of the cell-the mitochondria. Iron is also present inside the mitochondria as part of the cyto-chrome enzyme system, which is the mo-lecular machinery responsible for energy production. In essence, iron plays a vital role at every step of the energy producing pathway because of its ability to reversibly bind oxygen. Iron which is not being “put to work” in red blood cells, muscle cells or other cells is stored in the bone marrow.
The average man will have about 1,000 mg of stored iron., while women store only about 300 mg (1). Most men lose about one mg of iron a day, an menstruating women lose about 1.4 mg. This is variable, however, and can be as high as 2.2 mg a day (1). Unfortunately, your intestines are not very efficient at absorbing iron. On average only about 10 percent of the iron you ingest is actually absorbed. For this reason the RDA for iron is 10 mg a day for adult males and 15 mg a day for adult non-pregnant females. During pregnancy, an extra 30 to 60 mg each day is recommended . Dietary iron comes in two general forms, called heme iron and nonheme iron . Heme iron is an iron atom which is bound into a heme complex, a chemical constituent of the hemoglobin molecule found in red blood cells. As you might imagine, the best sources of heme iron are red meat and liver. Heme iron is relatively well absorbed-about 23 percent.
Only about three to eight percent of nonheme iron is absorbed. Thus, on average, iron absorption works out to be around 10 percent since most people get some mix of heme and nonheme iron in their diets . For some reason that is not clear, meat and vitamin C seem to improve the absorption of nonheme iron. It stands to reason that the people most likely to be iron deficient are vegetarians, since their diet is lower in total iron, plus lacks heme iron altogether. Female vegetarians would be especially at risk. If you eat less iron than your body loses on a daily basis, over time this will deplete the iron reserves in your bone marrow and you will develop iron deficiency. Your body can cope fairly well with this until the iron stores are severely depleted, and then the bone marrow can’t make enough hemoglobin anymore. Iron deficiency anemia results. In the United States about 10 percent of women are iron deficient and about six percent are so low on iron that they develop iron deficiency anemia. Less than one percent of adult American men are iron deficient.
The higher frequency of iron deficiency in women usually attributed to menstrual blood loss, and no doubt that does explain their greater (average) daily iron loss. However, it is interesting to note that about 50 percent of women consume less than 10 mg of iron each day. So women seem to have more of a problem with iron deficiency for a combination of two reasons: greater iron loss and lower iron consumption . It is clear that iron deficiency anemia reduces exercise performance (2-4). When hemoglobin concentrations are too low the oxygen carrying capacity of the blood is reduced. This will obviously compromise energy production. When iron deficiency anemia is corrected exercise performance improves. Some evidence suggests that milder iron deficiency, without anemia, may also compromise exercise perfor-mance. For example, when athletes who have borderline anemia (hemoglobin levels near the lower limit of the normal range) are given supplemental iron their heart rate during exercise decreases (5). What does that mean? Well, if your blood cannot carry as much oxygen as it normally should, you can compensate at least partially by pump-ing a larger volume of blood per minute. This is why anemic people have a faster heart rate.
Their hearts are pumping faster to try to keep up with the oxygen demands of the tissues. Also, blood lactate levels are higher in iron deficient athletes following exercise, and the lactate is reduced follow-ing correction of the iron deficiency (1). This indicates that the body is forced to rely more on anaerobic energy producing sys-tems to fuel exercise if it is iron deficient. It seems logical that this would be the case if oxygen delivery was compromised. The Parrillo Performance Mineral Elec-trolyte Formula™ provides five mg of iron per tablet in a special chelate form to enhance absorption. For the ultimate iron supplement, try Liver Amino Formula™, an ultra-purified liver preparation that supplies heme iron. Endurance athletes, women and vegetarians are at greatest risk for iron defi-ciency and should consider this supplement . It has been specially prepared and fat and cholesterol removed, and it provides high quality protein in addition to heme iron.
Zinc is another important trace element . It is found in meat, seafood and poultry (1). Zinc is bound to many enzymes and is required for the optimum function of many diverse metabolic pathways. Zinc deficiency results in reduced growth rate, anorexia (appetite loss) and impaired would healing (1). Several studies have shown that athletes are more prone to zinc deficiency than sedentary people (6-8). Among the various studies, about 23 percent of female runners were found to be zinc deficient. This seems to be a result of both increased zinc excretion in urine and sweat as well as decreased zinc intake. Although zinc is not normally thought to be a key mineral for exercise performance, it is required for the activity of lactate dehydrogenase. This is the enzyme that converts pyruvate to lactate and is required for anaerobic energy production, the energy pathways that power weight lifting. So while adding extra zinc probably won’t improve your lifting, a zinc deficiency could definitely hurt it. Chromium is of special interest to athletes because it helps insulin act more effectively, and thus improves carbohydrate utilization. Some studies suggest it also has effects on lipid metabolism and perhaps lean body mass. The RDA for chromium has been set at 50 to 200 micrograms (mcg) a day.
Most people consume between five and 150 mcg a day. Chromium deficiency is common, probably because it is depleted in refined foods (1). The best food sources for chro-mium are meats, whole grains, yeast, nuts, cheese and molasses (1). Urinary excretion of chromium is increased by exercise, so athletes probably have a higher chromium requirement (9). Several studies have examined the role of chromium in weight training athletes (10,11). One group of beginning weight trainers were given 200 mcg of chromium per day for 40 days. The group increased lean body mass signifi-cantly more than the group given a placebo. Similar results were observed with football players. In another study, women receiving chromium achieved greater increases in lean body mass during a 12-week weight lifting program, but no difference was seen in men. Some studies have also indicated that chromium might help fat metabolism as well. Other trials have not been able to demon-strate any significant effect of chromium on muscle or fat metabolism.
Why do different scientific reports sometimes contradict each other? The most likely explanation is that chromium probably does have some effect, and if you are chromium deficient energy metabolism may not proceed with optimal efficiency. However, if you already have adequate chromium stores, taking extra may not make any further difference. This seems to be the case with a lot of issues relating to vitamins and minerals. If you are deficient in a vitamin or mineral big prob-lems will develop. But if you have normal levels then taking extra doesn’t confer any additional benefit. I suspect this is the case with chromium. We can see an effect of chromium supplementation if the subjects in the study started off with chromium de-ficiencies. But if the study participants be-gan the trial with replete chromium stores, then chromium supplementation might not do anything. Since several studies have demonstrated a significant effect on lean body mass from chromium supplementa-tion, it is not unreasonable to suggest that serious athletes consider trying chromium for a month or two to see if it works for them. As is the case with many nutritional supplements, you could go to the doctor to get your chromium level checked but it’s cheaper just to try the supplement than to get the blood test. You may be one of the people for whom it works.
One exception to this idea that enough is good but more may not be better is the anioxidants. The body’s requirements for vitamins C and E to prevent deficiency status are quite low. However, for C and E to function effectively as antioxidants you have to take quite a bit more than the minimum amount required to prevent an overt vitamin deficiency. Similar effects seem to be seen with vanadyl in promoting glycogen storage, but I haven’t hound this to be true for chromium. The Parrillo Meneral-Electrolyte For-mula™ provides 25 mcg of chromium as chromium picolinate per tablet. Our vitamin and mineral supplements are designed to be taken one tablet with each meal. That will work out to be five or six tablets a day for most bodybuilders. This will supply 25 to 30 mg of iron each day, in addition to all of the other minerals included .
This is enough to ensure adequate iron and chromium stores even in intensely training atheltes, who lose more minerals daily and thus have higher requirements. In closing, I would like to say a few more words about calcium. Although it is not a trace mineral. One of the most worrisome nutritional practices I see in bodybuilding is the avoidance of dairy products without adequate regard to eating enough green leafy vegetables or calcium supplementa-tion. Most women increase bone density until age 30 or so, and then by age 35 bone mineral density begins to decline. The rapid decline which occurs after menopause can result in osteoporosis. One of the most important things you can do to prevent osteoporosis when you’re old is to build strong bones while you’re young. If you come out of middle age with relatively poor calcium status, that makes it all the more likely you’ll have problems when you’re older. Women especially (but men as well) should make sure that they get enough cal-cium from some source while they’re still young and increasing bone mineral density. You should consume 1,200 mg of calcium per day.
This is difficult to do even if you do use dairy products, and it is very hard if you don’t. We all know that most bodybuilders use relatively little dairy. So it becomes very important to supplement calcium to make sure you get enough . Sometimes it’s hard to talk athletes into doing this because cal-cium supplements don’t have any effect on exercise performance or on your physique. But, if you don’t use dairy products please be conscientious about taking a calcium supplement. Our Mineral Electrolyte™ provides 250 mg of calcium in each tablet. Four tablets a day is probably enough when combined with the calcium from your diet. Five tablets each day would guarantee that you meet your requirement. Plus Parrillo Hi-Protein Powder™ contains 280 mg of calcium per serving; Parrillo Optimized Whey Protein™contains 130 mg of calcium per serving; and the Parrillo 50/50 Plus™ contains 250 mg per serving for the vanilla, chocolate and orange cream flavors and 300 mg per serving for the milk flavor, which tastes just like whole milk minus the sugar and fat.
1. Haymes EM. Trace minerals and exer-cise. Chapter 11 in Nutrition in Exercise and Sport, Wolinsky and Hickson, editors. CRC Press, Boca Raton, 1994.
2 . Celsing F, Blomstrand E, Werner B, Pihlstedt P and Edblom B. Effects of iron deficiency on endurance and muscle enzyme activity in man. Med. Sci. Sports Exerc. 18:156 (1986).
3. Edgerton VR, Ohira Y, Hettiarachchi J, Senewiratne B, Garner GW and Barnard RJ. Elevation of hemoglobin and work tolerance in iron deficient subjects. J. Nutr. Sci. Vitam. 27:77 (1981).
4. Gardner GW, Edgerton VR, Senewiratne B, Barnard RJ and Ohira Y. Physical work capacity and metabolic stress in subjects with iron deficiency anemia. Am. J. Clin. Nutr. 30:910 (1977).
5. Ohira Y, Edgerton VR, Gardner GW, Gu-nawardena KA, Senewiratne B and Ikawa S. Work capacity after iron treatment as a function of hemoglobin and iron deficiency. J. Nutr. Sci. Vitam. 27:87 (1981).
6. Dressendorfer RH and Sockolov R. Hy-pozincemia in runners. Phys. Sportsmed. 8(4):97 (1980).
7. Haralambie G. Serum zinc in athltes in training. Int. J. Sports Med. 2:135 (1981).
8. Singh A, Deuster PA and Moser PB. Zinc and copper status of women by physical activity and menstrual status. J. Sports Med. Phys. Fitness 30:29 (1990).
9. Anderson RA, Plansky MM and Bryden NA. Strenuous running: acute effects on chromium, copper, zinc and selected clini-cal variables in urine and serum of male runners. Biol. Trace Elem. Res. 6:327 (1984).
10. Evans GW. The effect of chromium picolinate on insulin controlled parameters in humans. Int. J. Biosocial Med. Res. 11:163 (1989).
11. Hasten DL, Rome EP, Franks BD and Hegsted M. Anabolic effects of chromium picolinate on beginning weight training stu-dents. Int. J. Sports Nutr. 2: 343 (1993).