Nutrition, is a study of how food affects the health and survival of the human body. Human beings require food to grow, reproduce, and maintain good health. Without food, our bodies cannot stay warm, build or repair tissue, or maintain a heartbeat. Eating the right foods can help us avoid certain diseases or help us recover faster when illness occurs. These and other important functions are fueled by chemical substances in our food called nutrients. Nutrients are classified as carbohydrates, proteins, fats, vitamins, minerals, and water.
An individual needs varying amounts of each essential nutrient, depending upon such factors as gender and age. Here we try to present a general overview about these essential nutrients and their features..
Water
If the importance of a nutrient is judged by how long we can do without it, water ranks as the most important. A person can survive only eight to ten days without water, whereas it takes weeks or even months to die from a lack of food.
Source
|
Major Function
|
Quantity
|
Water is replenished by drinking liquids, preferably those without caffeine or alcohol, both of which increase the output of urine and thus dehydrate the body. Many foods are also a good source of water fruits and vegetables, for instance, are 80 to 95 percent water; meats are made up of 50 percent water; and grains, such as oats and rice, can have as much as 35 percent water.
| Water circulates through our blood and lymphatic system, transporting oxygen and nutrients to cells and removing wastes through urine and sweat. Water also maintains the natural balance between dissolved salts and water inside and outside of cells. | The human body is 65 percent water, and it takes an average of eight to ten cups to replenish the water our bodies lose each day. How much water a person needs depends largely on the volume of urine and sweat lost daily, and water needs are increased if a person suffers from diarrhea or vomiting or undergoes heavy physical exercise. |
Vitamins
Vitamin, any of the organic compounds essential for many living organisms to maintain normal health and development. Vitamins also assist in the formation of hormones, blood cells, nervous-system chemicals, and genetic material. The Vitamins are divided into Fat soluble -- A, D, E & K and water soluble -- all types of vitamin B & C.
Vitamins
| Dietary Source | Major Functions |
Deficiency Symptoms
|
A
| Liver, Egg yolk, Fish oil, Kidney, Milk fat, Dark green fruits and vegetables | Aids in maintenance of healthy bones, skin and hair, normal bone and teeth formation. Essential for vision, especially night vision. Helps repair body tissues. Reduces susceptibility to infections. Helps protect the membranes of the mouth, nose, throat & lungs. | Night blindness, rough, dry, scaly skin, loss of sense of taste, increased susceptibility to infections, retarded growth,defective teeth & gums. |
B1 (thiamin)
| Pork, Liver, Whole-grain and enriched cereals and breads, Legumes, Potatoes. | Helps produce energy in all cells of the body. Promotes growth & good muscle tone. Stabilizes the appetite. Essential for the normal functioning of the nervous system, muscles & heart. | Poor appetite, weakness, nerve damage, pins and needles in legs, fatigue, loss of weight, vague aches & pains. Beriberi, which affects the nervous and cardiovascular systems, and muscle wasting. |
| B2 (riboflavin) | Green vegetables, Liver, Wheat germ, Eggs and Cheese. | Necessary for carbohydrate, fat and protein metabolism. Essential for growth and general health. Promotes smooth skin. Necessary for the maintenance of good vision, nails & hair. Aids in the formation of antibodies and red blood cells. | Itching and burning eyes, which become sensitive to light. Cracks and sores in the mouth & lips, bloodshot eyes, dry and flaky skin, retarded growth, sore, red tongue, skin rash, digestive disturbances, depression . |
| B3 (Niacin) | Liver, poultry, meat, canned tuna and salmon, whole grain and enriched cereals, dried beans and peas, and nuts. | Helps metabolize protein, carbohydrate and fat. Maintains the nervous system. May reduce high blood pressure. Reduces the cholesterol level in the blood. Helps maintain healthy skin, tongue & digestive system. Improves circulation | Diarrhea and memory loss, weakness, irritability, headaches, muscular weakness, loss of appetite, gastric problems. |
| B6 (Pyridoxine) | grains, cereals, bread, liver, avocadoes, spinach, green beans, and bananas. | Aids in protein metabolism. Helps with normal brain function. Essential for normal growth. Helps maintain a proper balance of sodium & phosphorous in the body .Aids in the formation of antibodies. Aids in the production of hormones and the formation of red blood cells. Maintains the central nervous system | Skin disorders, cracks at the mouth corners, smooth tongue, convulsions, loss of hairdizziness, nausea, anemia,nervousness, arm & leg cramps and kidney stones. |
| B12 (Cobalamin) | Liver, kidneys, meat, fish, eggs, and milk. | Necessary for carbohydrate, fat and protein metabolism. Helps in the formation & regeneration of red blood cells. Helps maintain the central nervous system. Promotes growth in children. Needed for calcium absorption. Increases energy. | Weakness and fatigue, poor appetite, red-sore tongue or smooth tongue, growth failure in children, nerve damage. |
| Pantothenic Acid | Salmon, liver, kidney, egg, yeast, chicken, yogurt, sweet potato, milk, ham, corn, whole-wheat macaroni, kidney beans, avocado, mushrooms, soybeans, banana, orange, potato, broccoli, cantaloupe, peanut butter, apple, whole grain breads and cereals. | Helps convert proteins, carbohydrates, fats into energy. Synthesizes hormones and cholesterol. Fights infections by building antibodies. Improves the body's resistance to stress. | Retards growth, infertility, fatigue, irritability, skin abnormalities, weakness, depression, decreased resistance to infection, muscle cramps. |
Folic Acid ( Folacin )
| meats, leafy green vegetables, legumes, nuts, whole grains, and brewer's yeast | Necessary for DNA & RNA synthesis. Essential for the growth and reproduction of all body cells. . Especially important for women of childbearing age | Anemia , depression, impairs growth & intestinal problems. |
| C ascorbic Acid | Tomatoes, Fruits (especially citrus), Melon, Raw cabbage, Green leafy vegetables, Peppers | Essential for healthy teeth, gums, skin, blood and bones. Helps heal wounds, scar tissue, and fractures. Aids in the absorption of iron from plant sources of food. Builds resistance to infection, maintains white blood cell function. Aids in the treatment of the common cold. | Scurvy a disease that causes excessive bleeding, loose teeth, and swollen gums. Slow healing wounds and fractures. Swollen or painful joints. Nosebleeds, impaired digestion, loss of appetite and aching joints. |
| D | egg yolk, liver, tuna, and milk | Improves absorption and utilization of calcium and phosphorous. Essential for normal growth and development. Required for bone and teeth formation. Maintains a stable nervous system and normal heart action.. Helps with calcium absorption from food | Rickets (softening of bones) in infants and children, softening of bones in adults, tooth decay, muscular weakness, improper healing of fractures, spontaneous fractures, defective bone growth |
| E | Wheat germ, Vegetable oils, Egg yolk, Milk fat, Green leafy vegetables, Nuts | Strong anti-oxidant nutrient, which helps protect tissues (cells) against damage caused by free radicals.. Important for cell health and the proper functioning of the immune system. Protects cell membrane and tissues. Essential for normal growth and development. Aids in bringing nourishment to cells | Poor muscular and circulatory performance, anemia , abnormal fat deposits in muscles, dry skin. |
| K | leafy green vegetables, egg yolks, soybean oil, and liver | Essential for the formation of blood-clotting proteins. May aid in bone mineralization. | Diarrhea, increased tendency to hemorrhage. |
| Fats | ||||||
Fats, which provide 9 calories of energy per gram, are the most concentrated of the energy-producing nutrients, so our bodies need only very small amounts.
|
Dietary proteins are powerful compounds that build and repair body tissues, from hair and fingernails to muscles. Proteins are made of smaller units called amino acids. Of the more than 20 amino acids our bodies require, eight (nine in some older adults and young children) cannot be made by the body in sufficient quantities to maintain health. These amino acids are considered essential and must be obtained from food.
Dietary Source
|
Major Functions
|
Quantity
|
| Eggs, milk, meat, fish, poultry, vegetables, grains, dried peas and beans, rice, nuts, and soybean product. | Proteins helps to build and repair .body tissues. |
A healthy woman normally needs 45 grams of protein each day. Experts recommend that a pregnant woman consume 55 grams of protein per day, and that a breast-feeding mother consume 65 grams to maintain health. A man of average size should eat 57 grams of protein daily. To support their rapid development, infants and young children require relatively more protein than do adults. A three-month-old infant requires about 13 grams of protein daily, and a four-year-old child requires about 22 grams.
|
Minerals
Minerals are minute amounts of metallic elements that are vital for the healthy growth of teeth and bones. They also help in such cellular activity as enzyme action, muscle contraction, nerve reaction, and blood clotting. Mineral nutrients are classified as major elements (calcium, chlorine, magnesium, phosphorus, potassium, sodium, and sulfur) and trace elements (chromium, copper, fluoride, iodine, iron, selenium, and zinc).
Minerals
| Dietary Source | Major Functions | Deficiency Symptoms |
| Calcium : Calcium is a major mineral. The human body contains more calcium than any other mineral. Ninety-nine % of your body's calcium is in your bones. | Evaporated skim milk, skim or %1 milk, yogurt, greens, turnip greens, mustard greens, whole milk, buttermilk, salmon with bones, cottage cheese, dark green leafy vegetables, broccoli, almonds, cheese, tofu, corn , legumes (dried beans), calcium fortified soy milk | Builds and maintains strong bones and teeth. Helps to regulate heart rhythm and muscle contractions. Lowers blood pressure. Aids in regulation of water balance in cells. Helps regulate the passage of nutrients in & out of the cell walls. Important to normal kidney function | Rickets (softening of bones) in infants and children. Poor growth in children. Tooth decay, possibly high blood pressure, arm and leg muscles spasms, back and leg cramps. |
| Chromium | cereal, peas, cheese, liver, egg, spinach, chicken, mushrooms, wheat bread, apple, potatoes, vegetable oils. | Important in the metabolism of carbohydrates and fats. Works with insulin to help the body use glucose or blood sugar. Helps control the appetite | Low blood sugar levels. Impaired glucose tolerance. Impaired growth. |
| Copper | sunflower seeds, peanuts, mushrooms, crab, kidney beans, brown rice, potato, pinto beans, black beans, spinach, almonds, shrimp, nuts, raisins | Aids in the formation of red blood cells. Helps production of energy in the cells. Maintains blood vessels, nerves and the immune system. Helps proper bone formation & maintenance. Necessary for the absorption & utilization of iron | Anemia, Loss of color in the skin and hair, Damage to the brain and spinal cord, General weakness, Skin sores, Fatigue, Bone fragility. |
| Fluoride | Fluoride is not widely available in food. The primary means of obtaining fluoride is drinking and cooking with fluorinated water. | Helps harden tooth enamel, and protects against tooth decay. May help prevent osteoporosis, or brittle bone disease | Increases dental caries (cavities), Weak tooth enamel. |
| Iodine | Iodized salt, saltwater fish, milk. | Aids in the development and functioning of the thyroid gland. Needed for normal growth and development, regulates the body's production of energy. | Goiter, enlarged thyroid gland. Loss of physical and mental vigor. Dry skin and hair and weight gain. |
| Iron : They play a major role in health, since even minute portions of them can powerfully affect health. | Liver, pork, kidneys, red meat, 100% fortified cereal, poultry, eggs, cream of wheat, prune juice, legumes (dried beans) such as navy beans, lima beans and black-eyed peas, nuts, spinach, oysters, blackstrap molasses, enriched breads and cereals, dried fruits, dark green leafy vegetables. | Increases resistance to stress and disease. It is part of several enzymes and proteins. Needed for the red blood cell formation and oxygen delivery to tissues and the brain. Prevents fatigue and promotes good skin tone | Anemia , fatigue from anemia, decrease in immune function, paleness of skin, constipation, brittle fingernails. |
| Magnesium |
Whole grain products, brown rice, pineapple, wheat germ, brewed tea, green vegetables such as spinach and kale, oatmeal, black beans, almonds, strawberries, lentils
| Vital to many basic metabolic functions. . Aids in bone growth and the function of nerves, bones and muscles. Required for regulation of normal heart rhythm. Aids in regulation of blood pressure and water balance in cells. | Nausea, muscle weakness, irritability, abnormalities in heart rhythm, growth failure, leg cramps, kidney stones |
Carbohydrates
Carbohydrates are organic compounds containing carbon, hydrogen and oxygen. They are the human body's key source of energy. Carbohydrates are the most abundant organic compounds in nature. The carbohydrate group consists principally of sugar, starch, dextrin, cellulose, and glycogen, substances that form an important part of the human diet and that of many animals. Within living organisms, carbohydrates serve both structural and energy-storage functions.
Dietary Source
|
Major Functions
|
Quantity
|
| Rice, wheat, pulses, fruits, vegetables, sodas , sugar, honey and jaggery . | Provide energy sources for the brain, nervous system , heart and muscles.Carbohydrates some times spare proteins for the job of repairing tissue etc. | Heart disease and cancer. High blood pressure. Anemia and kidney disorders. |