
Risk Management Vitamin and Mineral Requirements
Vitamin and mineral needs depend on the level of energy expenditure. The energy expenditure of wildland firefighting is two to three times higher than the expenditure of the typical individual (up to 6,000 kilocalories per day for firefighters compared to 2,000 kilocalories per day for the typical individual).
Vitamins, minerals, antioxidants, and immune-friendly foods can be obtained by increasing caloric intake to match energy expenditure, by eating a variety of foods, and by eating enough servings of fruits, vegetables, and whole-grain products. Under the old U.S. Department of Health and Human Services and U.S. Department of Agriculture dietary guidelines, less active individuals were encouraged to eat two servings of fruits and three servings of vegetables daily. New (2005) guidelines call for everyone to eat four servings of fruit and five servings of vegetables daily. Firefighters should eat even more (see the Field Notes section).
Firefighters should begin deployment with a sound nutritional base.
Military studies demonstrate the need to begin an arduous deployment with a sound nutritional base. The Committee on Military Nutrition Research recommends that, whenever possible, individuals who have lost significant lean body mass should not be deployed until they regain the lean mass. Maintenance of body weight is a simple indicator of nutritional status. Loss of weight and lean tissue are signs of an energy imbalance. Failure to restore energy balance will harm physical performance and immune function and could open the door to upper respiratory infections and other illnesses.
VitaminsWhy are vitamins, which do not supply energy and are needed in the tiniest quantities, essential for life? In many cases, the answer lies in vitamins’ role as enzymes needed for cellular metabolism. For example, vitamin B1 (thiamin) is a coenzyme that removes carbon dioxide in a metabolic pathway. Without the vitamin, the metabolic pathway grinds to a halt, and intermediary compounds build up. Chronic lack of vitamin B1 leads to a vitamin deficiency characterized by weakness, wasting, and nerve damage (beriberi). Fortunately, the small amounts of vitamins needed are readily available from a variety of foods in a well-balanced diet. Doses that exceed the DRI (megadoses) do not improve function or performance, and they may be toxic.
Vitamins in food have proven more effective than vitamin supplements.
Vitamins are classified according to their solubility. Fat-soluble vitamins are ingested with fats in the diet. Water-soluble vitamins are found in a wide variety of foods. While excess water-soluble vitamins can be eliminated in the urine, excess fat-soluble vitamins may accumulate, sometimes to toxic levels. High doses of some water-soluble vitamins (B6 and C) also have been shown to be toxic. Table 1 lists the vitamins, their daily reference intakes for adults, important functions, and foods that are sources of these vitamins.
Minerals are important for enzymes and cellular activity, for some hormones, for bones, for muscle and nerve activity, and for acid-base balance. Minerals are available in many food sources, but concentrations are higher in animal tissues.
Excess intake of mineral supplements can pose problems, including diarrhea (magnesium, zinc), high blood pressure (sodium), or liver damage (iron). Mineral and vitamin supplements should not exceed the DRI (table 2).