Maintaining adequate levels of vitamins and minerals is important for bodily function, and therefore, athletic performance. As the activity level of an athlete increases, the need for different vitamins and minerals may increase as well. However, this need can be easily met by eating a balanced diet including a variety of foods. There is no evidence that taking more vitamins than is obtained by eating a variety of foods will improve performance.
Vitamins are chemical compounds that are required for normal growth and metabolism.
Some vitamins are essential for a number of metabolic reactions that result in the release of energy from carbohydrates, fats, and proteins.
There are thirteen vitamins, which may be divided into two groups:
• The four fat-soluble vitamins – vitamins A, D, E, and K
• The nine water-soluble vitamins – the B vitamins and vitamin C.
These two groups are dissimilar in many ways.
First of all, cooking or heating destroys the water-soluble vitamins much more readily than the fat-soluble vitamins.
On the other hand, fat-soluble vitamins are much less readily excreted from the body, compared to water-soluble vitamins, and can therefore accumulate to excessive, and possibly toxic, levels.
This means, of course, that levels of water-soluble vitamins in the body can become depleted more quickly, leading to a vitamin deficiency if those nutrients are not replaced regularly.
• Vitamin B1 (thiamine): Thiamine plays a central role in the release of energy from carbohydrates. It is involved in RNA and DNA production, as well as nerve function. Its active form is a coenzyme called thiamine pyrophosphate (TPP), which takes part in the conversion of pyruvate to acetyl coenzyme A (CoA) in metabolism.
• Vitamin B2 (Riboflavin): Riboflavin is involved in release of energy in the electron transport chain, the citric acid cycle, as well as the catabolism of fatty acids (beta oxidation).
• Vitamin B3 (Niacin, Nicotinic Acid): Niacin is composed of two structures: nicotinic acid and nicotinamide. There are two co-enzyme forms of niacin: nicotinamide adenine dinucleotide (NAD) and nicotinamide adenine dinucleotide phosphate (NADP). Both play an important role in energy transfer reactions in the metabolism of glucose, fat and alcohol.
Are essential for producing energy from the fuel sources in the diet.
Carbohydrate and protein foods are excellent sources of these vitamins.
B vitamins are water soluble vitamins, which means that are not stored in the body, so toxicity is not an issue.
Some female athletes may lack riboflavin, so it is important to ensure adequate consumption of riboflavin-rich foods, like milk. Milk products not only increase the riboflavin level but also provide protein and calcium.
• Has many functions in the body, and is crucial for calcium absorption. Athletes who train indoors for prolonged periods of time should insure that they consuming adequate amounts of vitamin D through diet.
Free Radicals, Antioxidants & Exercise:
Free radicals are highly reactive molecules that can cause damage to the cells and are thought to accelerate the aging process and contribute to cancer, heart disease and diabetes. They are found in cigarette smoke, environmental pollution and some medications. Exercise may also increase the production of free radicals.
The body has an elaborate defence system against free radicals in the form of antioxidant enzymes.
Vitamins A, C and E: are known as antioxidant vitamins and can protect the cells against free radical damage.
Although foods like citrus fruits, green vegetables and nuts contain antioxidant vitamins, some athletes feel the need to take a supplement due to the high level of training they undergo.
Exercise increases the oxidative stress on the body, increasing the need for vitamins C and E, which have an antioxidant effect.
Vitamin E is a fat soluble vitamin, found in fats in the diet such as nuts, seeds, and vegetable oils.
When an individual consumes excess fat-soluble vitamins (A, D, E and K), they are stored in fat throughout the body. Because they are stored, excessive amounts of fat-soluble vitamins may have toxic effects.
Minerals are different from the other nutrients discussed thus far, in that they are inorganic compounds (carbohydrates, proteins, lipids, and vitamins are all organic compounds).
The fundamental structure of minerals is usually nothing more than a molecule, or molecules, of an element.
The functions of minerals do not include participation in the yielding of energy. But they do play vital roles in several physiological functions, including critical involvement in nervous system functioning, in cellular reactions, in water balance in the body, and in structural systems, such as the skeletal system.
Because minerals have a very simple structure of usually one or more molecules of an element, they are not readily destroyed in the heating or cooking process of food preparation.
However, they can leak out of the food substance that contains them and seep into the water or liquid the food is being cooked in. This may result in a decreased level of minerals being consumed if the liquid is discarded.
There are many minerals found within the human body, but of the sixteen (or possibly more) essential minerals, the amount required on a daily basis varies enormously.
This is why minerals are subdivided into two classes:
Macrominerals include those that are needed in high quantities, ranging from milligrams to grams.
Calcium, phosphorus, sodium, potassium and magnesium. are macrominerals.
Microminerals are those necessary in smaller quantities, generally between a microgram and a milligram.
Examples of microminerals include zinc, copper, selenium and chromium.
Is lost through the course of an athletic event through sweat, so it may be necessary to replace sodium in addition to water during an event.
Sweating during exercise increases the concentration of salt in the body, so consuming salt tablets after competition and workouts is not advised.
This will draw water out of the cells, causing weak muscles.
Good sodium guidelines are to: 1) avoid excessive amounts of sodium in the diet and. 2) consider consuming beverages containing sodium during endurance events (> 2hours).
Potassium levels can decline during exercise, similar to sodium, though losses are not as significant.
Eating potassium-rich foods such as oranges, bananas and potatoes throughout training and after competition supplies necessary potassium.
Iron carries oxygen via blood to all cells in the body.
Needs for this mineral are especially high in endurance athletes.
Female athletes and athletes between 13 and 19 years old may have inadequate supplies of iron due to menstruation and strenuous exercise.
Female athletes who train heavily have a high incidence of amenorrhea, the absence of regular, monthly periods, and thus conserve iron stores.
Choosing foods high in iron such as red meat, lentils, dark leafy greens, and fortified cereals can help prevent iron deficiencies, but taking an iron supplement may be advised. It is best to consult a physician before starting iron supplements.
Calcium is important in bone health and muscle function.
Athletes should have an adequate supply of calcium to prevent bone loss.
Inadequate calcium levels may lead to osteoporosis later in life. Female athletes are more likely to have inadequate calcium consumption.
Low-fat dairy products are a good source of calcium.