From the Earth or Bottle? A Guide to Vitamin Supplementation

Vitamin supplements are very popular among active individuals. As many as 75% of recreational athletes take some type of supplement, ranging from a simple multivitamin to a complex assortment of pills. A good rule of thumb is that supplements should be part of the bigger picture for an optimal eating plan. The first priority should be to choose the fundamental foods that supply the vitamins and other nutrients needed for training.

Vitamins are metabolic catalysts that regulate biochemical reactions within the body. The body cannot manufacture vitamins, thus it is important to try to obtain them through food. To date, 13 vitamins have been discovered, each with a specific function. It is important to note that there is no scientific research that proves that extra vitamins offer a competitive edge. In the case of vitamin deficiencies, a vitamin supplement can help; however, vitamin deficiencies are usually related to a larger medical problem that needs attention. Keeping this in mind, some vitamins are stored in the body in large amounts (vitamins A, D, E and K) and others in smaller amounts (vitamins B and C), so it is virtually impossible for a nutritional deficiency to happen overnight.

Do active people need more vitamins? For most situations, the answer is no. Vitamins are the catalysts that are needed for metabolic processes to occur. Vitamins do not provide energy, and there is no evidence that vitamins improve performance. Another important point is that active individuals tend to eat more because of their increased activity. Thus, they will usually consume more vitamins from food since they are eating more. Having said this, some scientific studies suggest that the established RDAs for a few vitamins might be low for active individuals. The vitamins that are of importance for active individuals include the following:

• Thiamin
• Riboflavin
• Niacin
• Vitamin B₆
• Folic acid
• Biotin
• Pantothenic acid
• Vitamin B₁₂
• Vitamin C
• Vitamin D
• Vitamin E

Notice that 11 of the 13 vitamins are listed. All vitamins are important for active individuals, but the ones that aid in metabolism and cellular function are of utmost importance.

There are a few people who are at a higher risk for nutritional deficiencies and may immediately consider a daily multivitamin. These include:

• Those who are eating less than 1200-1500 calories per day.
• Those allergic to certain foods.
• Those who are lactose intolerant. This could result in low amounts of riboflavin and calcium.
• Those who are pregnant.
• Those who are contemplating pregnancy. Folic acid, iron and calcium are important for these individuals.
• Those who are complete vegetarians. This could result in low amounts of vitamins B₁₂ and D, riboflavin, iron and zinc.

The bottom line is that it is a good idea to try to obtain vitamins from foods first; however, a “perfect” eating plan does not exist. Therefore, taking a daily multivitamin that does not exceed 100-200% of the daily value of the vitamins may benefit the overall health of recreational athletes. Remember, each person is different, and a registered dietitian should be consulted to determine if nutritional deficiencies exist.

Here is an overview of the different vitamins, their functions and food sources (the foods listed are not the only ones where the vitamin is present, rather the more popular ones. If I listed all of the foods, the lists would be never ending!):

• Vitamin A (retinol) - Necessary for healthy eyes, skin and linings of the digestive and urinary tracts and the nose. Food sources include milk, dried apricots, squash, carrots, spinach and fortified products.
• Vitamin B₁ (thiamin) - Helps transform carbohydrates into energy. Food sources include potatoes, fish, bananas, ham, chicken, bread, cereal and enriched rice.
• Vitamin B₂ (riboflavin) - Necessary for energy release and for healthy skin, mucous membranes and nervous system. Food sources include spinach, steak, cottage cheese, milk, oranges, apples, enriched bread and enriched cereal.
• Vitamin B₃ (niacin) - Helps transform food into energy (metabolism), necessary for growth and for production of hormones. Food sources include tuna, potatoes, halibut, peas, cereal, corn, mushrooms, peanut butter, ground beef and enriched bread.
• Vitamin B₆ - Necessary for synthesis and breakdown of amino acids and aids in metabolism of carbohydrates. Food sources include peanut butter, chick peas, chicken, spinach, cereal, potatoes, bananas and lima beans.
• Folic Acid - Necessary for production of blood cells and a healthy nervous system. Food sources include spinach, broccoli, green beans, peas, lentils, asparagus, mushrooms, lima beans and oranges.
• Biotin - Needed for metabolism of carbohydrates, protein and fat. Food sources include nuts, split peas, eggs, cauliflower and mushrooms.
• Pantothenic Acid - Needed for metabolism of carbohydrates, protein and fat. Food sources include eggs, peanuts, mixed vegetables, steak, fish, wheat germ and broccoli.
• Vitamin B_{12 -} Needed for synthesis of red and white blood cells and for the metabolism of food. Food sources include chicken, meat, eggs, milk and yogurt.
• Vitamin C - Necessary for healthy connective tissue, bones, teeth and cartilage, enhances immune system. Food sources include bell peppers, broccoli, strawberries, oranges, potatoes, tomatoes and kiwi.
• Vitamin D - Needed for calcium and phosphorus metabolism and for healthy bones and teeth. Food sources include milk and fortified milk, fortified cereal and sunlight.
• Vitamin E - Necessary for nourishing and strengthening cells, antioxidant. Food sources include sunflower oil, wheat germ, sunflower seeds, almonds and whole wheat grain.
• Vitamin K - Necessary for blood clotting. Food sources include cabbage, spinach, broccoli and kale.

Choosing a Multivitamin

Multivitamins do have their place in a well-balanced eating plan, but remember they will not compensate for an unhealthy, unbalanced diet.

• Choose a multivitamin with the vitamins and minerals ranging from 100-200% of the Daily Value (DV). Don’t expect to find 100% of the DV for calcium and magnesium listed on a label in most cases, because these minerals are too bulky to include into one pill.
• Don’t purchase multivitamins that contain excessive doses of vitamins and minerals, especially minerals. High doses of one mineral can offset the benefits of another. For example, too much zinc can interfere with the absorption of copper.
• Choose a multivitamin with beta-carotene, not vitamin A. Beta-carotene is the precursor to vitamin A and acts as an antioxidant.
• Buy a supplement before its expiration date and store it in a cool, dry place.
• Ignore claims about “natural” vitamins. These usually tend to be a mixture of natural and synthetic vitamins and offer no additional benefits. The one exception is vitamin E, which is more potent in its natural form.
• Chelated supplements offer no advantages, nor do those made without sugar or starch.
• Just because the price tag is high does not mean the multivitamin is better. A well-known brand name costs more than generic but often times has the same amounts of vitamins and minerals in it. Buyer beware!
• Take a vitamin with a label that states it has passed the 45-minute dissolution test. A supplement is of little value unless it can be absorbed by the body.
• To optimize absorption, take a multivitamin with or after a meal.

References:

1. Modern Nutrition in Health and Disease. Ninth Edition. 1999.
2. Nutrition Concepts and Controversies. Ninth Edition. 2002.
3. Sport Nutrition for Health and Performance. 2000.