Drug Free Sport Staff Writers

Drug Free Sport Staff Writers

Tuesday, November 30, 2010

Minerals: Macrominerals and Trace Elements

Minerals are naturally occurring substances, chemical elements, that the body needs to carry out its processes. The are macrominerals, those that are found in body in amounts greater than 5 grams, and trace elements, those found in amounts less than 5 grams. Minerals help the body to maintain fluid balance and acid-base balance (pH). Each mineral has a specialized role in this process.


Calcium is the body’s most abundant mineral and is stored in the bones and teeth. It is an important part of bone structure and this stored calcium can release into the body if a drop in blood calcium concentration occurs. Calcium is important in nerve transmission, helps maintain blood pressure, aids in blood clotting, is needed for muscle contraction, allows secretion of hormones, digestive enzymes, and neurotransmitters, and activates cellular enzymes. Deficiencies cause bone loss or stunted growth; toxicity interferes with the absorption of other minerals and risk of kidney stones.

DRI: Adults 19-50 yrs old 1,000mg/day
Food sources:
1c milk 300mg
1.5c broccoli 93mg
1.5 oz cheddar cheese 306mg

Phosphorus is found mostly in the bones and teeth and helps to maintain acid-base balance, assists in energy metabolism, and forms part of cell membranes. Phosphorus needs are easily met by most diets. Deficiencies cause muscle weakness and bone pain; toxicity causes calcification of soft tissues.

DRI: 700mg/day
Food sources:
1c cottage cheese 341mg
3oz sirloin steak 208mg
1c milk 235 mg

Magnesium is used in building protein, helps the body use energy, and plays a role in immune function.

DRI: Men 400 mg/day; Women 310mg/day
Food sources:
½c black beans 60mg
1c yogurt 43mg
½c spinach 78mg

Sodium maintains fluid and electrolyte balance and is essential to muscle contraction and nerve transmission. A sodium deficiency in an athlete can lead to cramping. Most diets in the US are extremely high in sodium and if you look at food labels you will quickly see how much sodium is in many of your favorite foods. Too much sodium can increase blood pressure. DRI recommended intakes for sodium is 1,500mg/day. Tolerable Upper Intake Levels are set at 2,300mg. Try to stay below the UI by monitoring your daily sodium intake, eating less processed foods, and cooking without salt.

Potassium plays a role in maintaining fluid and electrolyte imbalance, cell integrity and heartbeat. Dehydration leads to a loss of potassium . Potassium from foods is safe, but when injected into the vein, can stop the heart. Please check with a physician before taking potassium supplements that may deliver a large dose causing muscle weakness or vomiting.

DRI: 4,700mg/day
Food sources:
1c orange juice 496mg
1 baked potato 844mg
1 banana 422 mg

Chloride helps maintain fluid and electrolyte balance. No known diets lack chloride, and the principal food source is salt.

Sulfate is used to synthesize sulfur-containing compounds such as hair, skin, and nails.

Trace Minerals

Iodine is part of thyroxine, the hormone that influences energy metabolism. It is an additive in milk and bakery products as well as being found naturally in seafood. The DRI is 150 micrograms.

Iron carries oxygen in the blood and muscles. It is required for energy metabolism. The amount absorbed increases when the body is deficient and decreases when iron is abundant. Iron deficiencies can cause anemia, weakness, fatigue, impaired immunity, and other health issues. Iron fortified foods can help individuals avoid deficiency.

DRI: Men 8mg/day; Women 18mg/day
Food sources:
½c black beans 1.8mg
½c spinach 3.2mg
3oz beef steak 2.6mg

Zinc assists enzymes in cells associated with hormones, taste perception, synthesis of genetic material and proteins, reproduction, wound healing and transport of vitamin A. Too much zinc from supplements can block copper and iron absorption. Zinc from foods is nontoxic.

DRI: Men 11mg/day; Women 8mg/day
Food sources:
1c yogurt 2.2mg
3oz pork chop 2mg
3oz shrimp 1.5mg

Selenium works to help prevent oxidative harm to the body’s cells and tissues. Selenium is abundant in unprocessed foods such as vegetables and grains grown in selenium rich soil, as well as meats and shellfish. DRI: 55micrograms/day

Fluoride is beneficial to the diet because it helps stabilize bones and prevent tooth decay. It is found most often in drinking water. DRI: Men 4mg/day; Women 3mg/day

Chromium works to control blood glucose concentrations. It can be found in unrefined foods and whole grains. DRI: 50 micrograms/day

Copper is needed to form hemoglobin and collagen and also plays roles in the body’s handling of iron. Water, seafood, nuts, and vegetables are all sources of copper. DRI: 900micrograms/day.

Molybdenum (DRI: 45 micrograms/day) and manganese (DRI: Men 2.3mg/day; Women 1.8mg/day) work with enzymes within the body.

All trace minerals can be toxic in excess, which is usually a result from high levels taken in a variety of nutrient supplements.

Supplementation of antioxidants does not improve exercise performance and athletes can obtain sufficient intakes of natural antioxidants by eating a well-balanced diet including a variety of fruits and vegetables. There has not been evidence that supplementation of minerals can act as an ergogenic aid, although some athletes may need to pay attention to sodium and potassium levels if exercising for long periods of time or in hot, humid environments. Sports drinks include these minerals to help replenish losses due to sweat during exercise.

If you compete in a sport such as wrestling, gymnastics, or dance, where weight may be restricted or kept low, talk with a sports nutritionist or registered dietitian for suggestions on foods you need to include to get adequate nutrients.

Poor diets are the most common reasons for nutrient deficiencies in athletes. A well balanced diet including all food groups (meat, dairy, fruits, vegetables, and grains) can provide all the minerals the body needs. The increase in calories needed to fuel performance and maintain energy, increases the intake of minerals and satisfies the needs of athletes. Supplements do not make up for a poor diet.

Bonci, L. Sports Nutrition for Coaches. 2009.
Jeukendrug, A. and M. Gleeson. Sport Nutrition: An introduction to energy production and performance, 2nd ed. 2010.
Sizer, F. and E. Whitney. Nutrition Concepts and Controversies, 10th ed. 2006.
Skolnik, H. and A. Chernus. Nutrient Timing for Peak Performance. 2010.

Wednesday, November 17, 2010

The Fat Soluble Vitamins: A, D, E, and K

The fat soluble vitamins, A, D, E, and K, are stored in the liver and fatty tissues of the body until they are needed. They are found most often in the fat and oil of foods. The body can survive weeks without consuming foods that contain these vitamins as long as the diet as a whole provides average amounts that approximate DRI recommended intakes. Because these vitamins are stored by the body, toxicity is easier to reach if you take in too much.

Vitamin A (retinol): Vitamin A is a versatile vitamin that has a role in gene expression, maintenance of body linings and skin, immune defenses, bone and body growth and normal development of cells. The role of vitamin A in vision is probably the most familiar, helping to maintain a healthy cornea.

Vitamin A deficiency is a worldwide health problem because of poor nutrition and starvation. Researchers are close to developing a Vitamin A rich rice to serve to the world’s children who lack the vitamin. On the other side, Vitamin A toxicity, over 3000 micrograms/day, can pose health problems such as skin rashes, hair loss, birth defects, liver failure, and death.

DRI: Men 900 micrograms/day; Women 700 micrograms/day
Food Sources:
1c fortified milk 150 micrograms
½c carrots 671 micrograms
3 apricots 100 micrograms

Vitamin D (calciferol): Vitamin D is unique in that the body can get the amount it needs by synthesizing sunlight. This sounds simple, as being in the sun each day would mean you would not need to consume Vitamin D in food. However, research has shown many people are deficient in this vitamin. To counter this, many foods are being fortified with Vitamin D.

Vitamin D helps to regulate blood calcium and phosphorus levels to help maintain bone integrity. Vitamin D also plays a role in the functions of the brain, heart, stomach, pancreas, skin and reproductive organs.

Too little Vitamin D can cause rickets, an abnormality in the bones. Too much Vitamin D can cause too much calcium to be deposited in soft tissues and organs causing them to malfunction. More is not always better, especially in children and young adults.

DRI: Adults (19-50yr) 5 micrograms/day
Food Sources:
3oz salmon 4.3micrograms
1c fortified milk 2.5micrograms
3oz shrimp 3.0micrograms

Vitamin E (alpha-tocopherol): Vitamin E is an antioxidant and serves as a defender against damage to cell components and membranes. This action is very important in the lungs. White blood cells also depend on Vitamin E. Excess Vitamin E from supplements can increase the effects of anticoagulant medications.

DRI: 15mg/day
Food Sources:
Widespread in foods, especially those containing oils.
2tbs sunflower seeds 9mg
1tbs canola oil 2.4mg
1tbs mayo 3.0mg

Vitamin K (menadione): Vitamin K helps to clot the blood by synthesizing proteins. It is also needed for synthesis of some bone proteins. It is important to know that Vitamin K may interfere with blood thinning medications. Some bacteria in the intestines can synthesize Vitamin K for the body’s use.

DRI: Men 120 micrograms/day; Women 90 micrograms/day
Food Sources:
½ cauliflower 20micrograms
1c lettuce 60micrograms
1tbs canola oil 19micrograms

It seems that athletes may need more of Vitamins A and K, than their non-athlete counterparts. Typically, the higher needs are met by the increased number of calories required for in an athlete’s diet to power performance and maintain energy levels. There have not been conclusive studies showing that supplementation can actually increase performance.

Next week, we will focus on the minerals needed by the body.

Bonci, L. Sports Nutrition for Coaches. 2009.
Sizer, F. and E. Whitney. Nutrition Concepts and Controversies, 10th ed. 2006.
Skolnik, H. and A. Chernus. Nutrient Timing for Peak Performance. 2010.

Thursday, November 11, 2010

The Water Soluble Vitamins: Vitamin C and the B Vitamins

Water soluble vitamins, Vitamin C and the B Vitamins, are absorbed directly into the bloodstream and travel freely. For the most part, these vitamins are not stored in tissues to a great extent and excesses are excreted from the body. This also means that these must be ingested each day. While these vitamins seldom reach toxic levels, high amounts in some supplements can cause levels in the body to reach toxicity.

Vitamin C (ascorbic acid): Vitamin C works to maintain connective tissue and assists enzymes in performing their jobs, in particular enzymes involved in formation and maintenance of collagen. Collagen helps heal wounds, mend fractures, and support capillaries, preventing bruises. Immune system cells maintain high levels of Vitamin C as well. Vitamin C promotes iron absorption in the intestines.

A popular belief is that Vitamin C will prevent colds. Studies have shown that taking extra Vitamin C does not actually prevent a cold, although it may shorten its duration and lessen the severity of the symptoms.

Too much Vitamin C can be dangerous for people who have an overload of iron in their system or for those on medications to prevent blood clotting.

DRI: Men 90mg/day; Women 75mg/day
Food sources:
½ c red pepper 142mg
½ c orange juice 62mg
½ c strawberries 43mg
½ c sweet potato 20mg

B Vitamins: B Vitamins work together, and as a whole, help the body use fuel from carbohydrates, fat and proteins. Thiamin, Riboflavin, Niacin, Biotin and Pantothenic Acid support energy metabolism in every cell of the body.

Thiamin (B1) also aids nerve function.
DRI: Men 1.2mg/day; Women 1.1 mg/day
Food sources:
½ whole wheat bagel .19mg
¾ cup enriched cereal .38mg
1 baked potato .22mg
½ cup green peas .23mg

Riboflavin (B2) also supports normal vision and skin health.
DRI: Men 1.3mg/day; Women 1.1mg/day
Food sources:
1 c milk .45mg
1 c cottage cheese .32mg
½ c spinach .21mg
3 oz pork chop .23mg

Niacin (B3) contributes to skin health and nervous and digestive system function.
DRI: Men 16mg/day; Women 14mg/day
Food sources:
3 oz chicken breast 8.9mg
3 oz tuna 11.3mg
¾ c enriched cereal 5.0mg
1 baked potato 3.3mg

DRI: 30 micrograms/day
Food sources: Meat, milk, egg yolk, legumes, most vegetables

Pantothenic Acid
Food sources: meat, eggs, most vegetables, whole grain cereal products

Folate helps the body make new cells.
DRI: 400 micrograms/day
Food sources:
1 c spinach 58 micrograms
½ c avocado 45 micrograms
½ c pinto beans 145 micrograms

Vitamin B12 (cobalamin) helps to convert folate to its active form and helps maintain the sheath around nerve cells.
DRI: 2.4 micrograms/day
Food sources:
3 oz sirloin steak 2.0 micrograms
1.5 oz Swiss cheese 1.5 micrograms
1 c cottage cheese 2.0 micrograms

Vitamin B6 (pyridoxine) is needed in protein metabolism and helps convert one amino acid to another.
DRI: 1.3mg/day
Food sources:
1 Banana .66mg
3oz chicken breast .35mg
½ c spinach .22mg

Athletes may need more of some water soluble vitamins than their non-athlete counterparts. Typically, the higher needs are met by the increased number of calories that an athlete already needs to power performance and maintain energy levels, as long as the calories come from a combination whole grains, vegetables, fruits, meat and dairy, and not from an extra bag of chips. There have not been conclusive studies showing that supplementation of the B Vitamins or Vitamin C can actually increase performance.

Next week, we will discuss the fat soluble Vitamins A, D, E, and K.

Bonci, L. Sports Nutrition for Coaches. 2009.
Sizer, F. and E. Whitney. Nutrition Concepts and Controversies, 10th ed. 2006.
Skolnik, H. and A. Chernus. Nutrient Timing for Peak Performance. 2010.

Thursday, November 4, 2010

Introduction to Vitamins and Minerals

Vitamins and Minerals are nutrients the body needs to carry out its processes. Often, the REC receives questions regarding the supplementation of different vitamins and minerals. There are many products on the market, including multivitamins, that boast positive health affects and an ability to help athletic performance. Many athletes, and even the general public, aren’t aware of their needs when it comes to vitamins and minerals, or what food sources they come from.

Some people operate on the assumption that if vitamins and minerals are good for you, then it can’t hurt to take more than you need. This isn’t necessarily true. Vitamins and minerals can be toxic at certain levels and may also interfere with medications an individual is on or with the actions of other vitamins and minerals in the foods you eat. If you eat well and have a balanced diet, including a wide variety of fruits and vegetables, supplementation is not necessary unless you have a specific deficiency. Remember as an active athlete, your caloric and nutrient needs may be higher than non-athletes. This makes it even more important that you consume a diet that includes all food groups. We will give you examples of foods and their nutrient levels to show you how food can help you reach the amount of nutrients your body needs.

The Recommended Dietary Allowance (RDA) is a nutrient intake goal for healthy individuals (no nutrient deficiencies) in certain age and gender categories. The Adequate Intake levels are set for nutrients when there is not enough scientific evidence to support an RDA value. Daily Reference Intakes recommended intakes (DRI) will be used to describe nutrient intakes as there is no need to distinguish between them for our purposes. DRI recommended intakes are different from the Daily Values that are listed on food labels. Daily Values allow consumers to compare nutrient and energy contents of packaged foods and are percentages based on certain caloric intake levels. The DV does not take into account different needs for different age and gender groups and are intended to help compare nutritional value of foods.

This month, we will take a look at different vitamins and minerals and their functions, DRI recommended intakes, and what food sources supply them. We will start next week by focusing on the water soluble vitamins. Then we will explain fat soluble vitamins and their actions within the body. The final post of the month will focus on minerals.