Micronutrients include vitamins and minerals. Minerals and vitamins, although part of energy-yielding reactions in your body, cannot provide energy directly. Many have antioxidant, or cell-protecting, functions (e.g., vitamins A, C, and E; copper; iron; selenium; and zinc). It is important to consume the DRI amounts for vitamins and minerals (or at least obtain 70% of the DRI) to maintain overall health. Below provides a listing of the major vitamins and minerals, including common sources as well as concerns with consuming too much or too little.
• Thiamin (vitamin B1) – needed for carbohydrate and protein metabolism and functioning of the heart, muscles, and nervous system – Deficiency: Weakness, fatigue, psychosis, nerve damage – Examples of food sources: fortified breads and cereals, whole grains, lean meats (e.g., pork), fish, soybeans
• Riboflavin (vitamin B2) – needed for energy production and red blood cell production – Deficiency: fatigue, sore throat, and swollen tongue (all rare) – Food Sources: lean meats, eggs, nuts, green leafy vegetables, milk and milk-based products, fortified cereals
• Niacin (vitamin B3) – needed for energy production and health of digestive system, skin, and nerves – Deficiency: pellagra (symptoms include diarrhea, dementia, and dermatitis) – Toxicity: liver damage, peptic ulcers, skin rashes, skin flushing – Food sources: poultry, dairy products, fish, lean meats, nuts, eggs
• Pantothenic Acid – needed for energy production – Toxicity: Diarrhea (rare) – Food sources: eggs, fish, milk and milk products, lean beef, legumes, broccoli
• Biotin – needed for energy production – Food sources: eggs, fish, milk and milk products, lean beef, legumes, broccoli
• Vitamin B6 – needed for protein metabolism, immune and nervous system functions – Deficiency: dermatitis, sore tongue, depression, confusion – Toxicity: neurological disorders and numbness – Food Sources: beans, nuts, legumes, eggs, meats, fish, whole grains, fortified breads and cereals
• Folate – need for cellular growth, replication, regulation, and maintenance – Deficiency: diarrhea, fatigue, headache, sore tongue, poor growth – Food sources: beans and legumes, citrus fruits, whole grains, dark green leafy vegetables, poultry, shellfish
• Vitamin B12 – needed in red blood cell formation, neurological function, role with metabolism – Deficiency: anemia, numbness, weakness, loss of balance – Food sources: eggs, meat, poultry, shellfish, milk and milk products
• Vitamin C – needed for its antioxidant properties, iron absorption, and role with connective tissues (skin, bones, and cartilage) – Deficiency: dry/splitting hair, gingivitis, dry skin, depressed immune function, slow wound healing – Toxicity: gastrointestinal disturbances (cramps and diarrhea) – Food sources: citrus fruits, red and green peppers, tomatoes, broccoli, greens
• Vitamin A – important role in vision, as well as health teeth, bones, and skin – Deficiency: night blindness, deceased immune function – Toxicity: toxic at higher doses, birth defects – Food sources: eggs, milk, cheese, liver, kidney (also, beta carotene, which can be turned into a form of Vitamin A, is found in orange and dark green vegetables)
• Vitamin D – needed for calcium absorption and for bone growth and remodeling – Deficiency: osteoporosis – Toxicity: kidney stones, and calcium deposits in heart and lungs – Food sources: skin exposure to sunlight, fish, fortified milk
• Vitamin E – needed for its antioxidant properties and important role in immune function – Deficiency is rare – Toxicity: increase risk of death at higher doses (400 IU or higher) – Food sources: wheat germ, nuts, seeds, vegetable oils
• Vitamin K – major role in blood clotting – Deficiency: excessive bleeding due to clotting impairment, more likely to bruise – Food sources: green vegetables, dark colored berries
• Calcium: needed for bone growth and maintenance, muscular contractions, cardiovascular and nervous system functions, hormone and enzyme secretion – Deficiency: numbness, muscle cramps, convulsions, lethargy, abnormal heart rhythms, low bone mineral density – Toxicity: high amounts for a long time can increase risk of kidney stones – Food sources: milk, cheese, yogurt, leafy green vegetables
• Iron – major role in oxygen transport in the blood – Deficiency: iron deficiency anemia, lack of energy, headache, dizziness, weight loss – Toxicity: fatigue, dizziness, nausea, vomiting, weight loss, shortness of breath – Food sources: dried beans, eggs, liver, lean red meat, oysters, salmon, whole grains
• Zinc – major role in energy production, immune function, and wound healing – Deficiency: slow growth, impaired immune function, hair loss, delayed healing of wounds, problems with sense of taste and smell – Toxicity: vomiting, abdominal cramps, diarrhea, and headaches can occur with large amount of supplements – Food sources: beef, pork, lamb, peanuts, peanut butter, legumes
• Chromium – enhances the function of insulin and involved with the metabolism of fat and carbohydrates – Deficiency: impaired glucose tolerance – Food sources: beef, liver, eggs, chicken, bananas, spinach, apples, green peppers
• Magnesium – major role in proper muscle and nerve function – Deficiency: muscle weakness, sleepiness (all rare) – Food sources: dark green leafy vegetables, nuts, whole grains, soy products
• Selenium – helps with antioxidant function to prevent cellular damage – Deficiency: joint/bone disease, mental retardation (all rare) – Toxicity: selenosis (gastrointestinal upsets, hair loss, fatigue, irritability, some nerve damage) (rare) – Food sources: vegetables, fish, shellfish, grains, eggs, chicken, liver
• Copper – role in the formulation of red blood cells as well as healthy blood vessels, nerves, immune system, and bones – Deficiency: anemia and osteoporosis – Toxicity: poisonous in large amounts – Food sources: organ meats (kidneys, liver), oysters and other shellfish, whole grains, beans, nuts, potatoes, dark leafy greens
• Iodine – major role in the metabolism of cells and in normal thyroid function – Deficiency: goiter or hypothyroidism – Toxicity: reduced functioning of the thyroid gland (rare) – Food sources: iodized salt, seafood (e.g., cod, sea bass), kelp
• Phosphorus – major role in the formulation of bones and teeth, also involved in the utilization of fats, carbohydrates and protein for growth and maintenance of cells, and for energy production – Deficiency: rare (available widely in the food supply) – Toxicity: deposits in muscle (rare) – Food sources: milk and milk products, meat
Source: U.S. Department of Health and Human Services and National Institutes of Health, U.S. National Library of Medicine 2010, and Institute of Medicine, National Academy of Science 1997, 1998, 2000, 2001, 2005, and 2011
You may be feeling overwhelmed thinking about consuming each of the macronutrients and the micronutrients (all the vitamins and minerals) each day. However, if you consume a diet that is varied, includes five to eight servings of fruits and vegetables per day, and is composed mostly of whole foods and less of processed foods, you will be doing your body well. You may also feel daunted by the idea of consuming five to eight servings of fruits and vegetables per day, but remember that these servings include fruits and vegetables (not five to eight servings of each!), and that a serving can be a medium banana, 4 ounces (113 ml) of 100% fruit juice, ½ cup of broccoli, and the like. The website MyPyramid.gov can help you better understand serving sizes, as well as your particular requirements. When making food choices, consider the following simple guidelines:
• Whole grain is better than processed or white grain.
• More color is better than less color (e.g., dark green leafy vegetables, deep red vegetables and fruits, and dark blue or purple fruits have more vitamins and minerals than those with less color).
• Less-processed foods are best.
Often, contemplating how to improve your diet is difficult because it is hard to know where to start. A with any change, focus on short-term and long-term goals. Consider a person, who has a long-term goal of cutting down on fat intake as well as improving the nutrient content of his diet (e.g., increasing his consumption of whole grains, fruits, and vegetables). A short-term goal might be: I will pack my lunch (including vegetable sticks, lean meat sandwich on whole wheat bread, piece of fruit, and a yogurt cup) rather than stopping at fast-food restaurants each day for the upcoming week. This is a SMART goal. It is specific in terms of the activity as well as the time frame. At the end of the week, you can reflect on whether you packed a lunch (measurable). It provides accomplished without excessive difficulty (i.e., it is realistic). A specific time frame is provided so that the action starts now rather than being too open-ended (i.e., it is time-ancbored).
• To stop at a local farmer’s market each weekend for the next month to select enough fruit to provide at least two selections each day
• To include a salad with Romaine lettuce, tomatoes, onions, peppers, and carrots, topped with low-fat vinaigrette dressing, for dinner on at least two days during the upcoming week
• To replace an afternoon candy bar from the vending machine with a piece of fruit and some almonds
Building on short-term goals, and maintaining those healthy behaviors, will ultimately result in success at reaching the long-term goal.
Water is required nutrient for all living beings. Water is important for hydration; however, it may be valuable for disease prevention as well. For example, researchers have found a relationship between water intake and reduction of gallstones and kidney stones as well as between water intake and colon cancer. Similarly, maintaining a sufficient intake of water while flying may help reduce the risk of blood clots.
With respect to physical activity, water is important for hydration. When you are active, you need to remain in a euhydrated (balanced) state. Water balance means that you are replacing the fluid you lose through sweating and urine production. Hydration does not just occur from drinking water. Water can be gained from food, which makes up about 20% of total water intake, and as well as from other beverages. Thus, although water is an excellent source of fluid, other beverages, such as tea, milk, coffee and 100% juice, can also fulfill your fluid needs.
Sweating during exercise is one way the body tries to cool you. Sweat is composed of water as well as other substances such as electrolytes (sodium, potassium, and chloride). The amount of electrolytes in sweat varies among people depending on a eat rate, fitness level, electrolyte intake, as well as the temperature of the environment. Sodium (salt) is one electrolyte you may have noticed dried on your skin after prolonged sweating. Replacement of sodium lost in the sweat is not an issue for most people, considering that, in general. Americans consume far more salt than their bodies need.