Food, clothing, and shelter are the basic needs of man. The nutritional elements of food which are essential for all the life processes, make food one of our basic needs. This is why ‘food’ comes first in our basic necessities. When we talk of food basics, we intend to express the body’s requirement of food. Let us look at food’s nutritional elements and the roles they play in maintaining metabolism and overall health.
Carbohydrates, fats, vitamins, minerals, proteins, fiber, and water constitute the basic nutritional elements of food. They are categorized based on the amounts in which the body requires them. The nutrients required in relatively larger amounts by the body are classified as macronutrients. Carbohydrates, fats, proteins, water, and fiber belong to this class of nutrients. Vitamins and minerals are required in comparatively smaller amounts and hence called micronutrients.
Carbohydrates, fats, and proteins are sources of energy. Carbohydrates give four calories of energy per gram while one gram of fat gives nine calories of energy. Molecules of carbohydrates and fats are composed of carbon, hydrogen, and oxygen atoms. Proteins additionally contain nitrogen atoms. Foods contain some or all the nutrients in certain proportions. It is these nutritional elements that help maintain metabolism of the body and keep us healthy.
Based on the number of sugar units they contain, carbohydrates are classified as monosaccharides, disaccharides, or polysaccharides. They contain 1, 2, and 3 or more sugar units respectively. Carbohydrates require less water to digest and make up the most common source of energy. As the body can obtain energy from proteins and fats, they are not essential nutrients. Carbohydrate-rich foodstuffs include bread, pastas, rice, and beans.
They contain fatty acids and glycerol. If a molecule of fat has all its carbon atoms bonded to hydrogen atoms, it is known as a saturated fat. If some of its carbon atoms are doubly bonded to each other, it is an unsaturated fat. Saturated fats are solids while unsaturated fats are liquids. Fats disintegrate to form fatty acids and glycerol. Fatty acids are an essential dietary need while glycerol is used to produce glucose. This makes fats the energy stores of our body. Apart from this, they act as a buffer against diseases, maintain body temperature, and assist the functioning of cells. They are also responsible for healthy skin and hair. Fats act as solvents for vitamins A, D, E, and K. The body can absorb these vitamins only with the help of fats. Nuts, oil, and butter contain fats.
Vitamins work like hormones. They regulate cell and tissue growth. They are vital nutrients. Each of the vitamins, if consumed in amounts less than those required by the body, leads to a deficiency disease. This makes evident their importance to the body.
Vitamin A plays a major role in good eyesight. Its deficiency leads to night blindness. Sources of this vitamin include carrots, cod liver oil, sweet potatoes, bell peppers, and green leafy vegetables.
Vitamin B comes in different forms such as B1, B2, B3, B5, B6, B7, B9, and B12. All B vitamins help the body convert carbohydrates into glucose, which is used by the body to generate energy.
Vitamin B1 with the chemical name thiamine is responsible for neural function and carbohydrate metabolism. It is necessary for healthy mucus membranes. Rice bran is a major source of vitamin B1. Other sources include green peas, spinach, sunflower seeds, and soy milk. Symptoms of thiamine deficiency include irritability, confusion, and weight loss. In mammals, the deficiency can lead to a optic neuropathy and a disease called beriberi.
Vitamin B2, known as riboflavin is instrumental in the maintenance of normal vision and a healthy skin. It is a coenzyme used in the metabolism of energy. It helps in the production of vitamins B3 and B6. Cheese, beef, and lamb, milk and dairy products, as well as eggs, mushrooms, broccoli, and green leafy vegetables are among the good sources of vitamin B2. Its deficiency can lead to reddening of lips, mouth ulcers, soar throat, and iron deficiency anemia.
Known as niacin or nicotinic acid, vitamin B3 plays a role in DNA repair and in the production of steroid hormones in the adrenal gland. Good sources of this vitamin include asparagus, tomatoes, green beans, potatoes as well as trytophan sources like eggs and cheese. Lack of vitamin B3 in the diet, can lead to nausea, skin and mouth lesions, and anemia. Niacin deficiency is referred to as pellagra.
Vitamin B5, known as pantothenic acid is used in the synthesis of coenzyme-A and for the synthesis and metabolism of proteins, carbohydrates, and fats. Dietary sources of this vitamin include avocados, broccoli, tomatoes, cauliflower, salmon, chicken, and sunflower seeds. This vitamin is found in very small quantities in almost all foods. The deficiency of vitamin B5 has symptoms similar to other B vitamin deficiencies, but the occurrence is very rare.
The metabolically active form of vitamin B6 is PLP. The site for the metabolism of this vitamin is the liver. This vitamin is involved in the amino acid metabolism, glucose metabolism, lipid metabolism, synthesis of hemoglobin, and plays a role in gene expression. It is necessary for the development of a healthy immune system. It plays a crucial role in fertility. It can be found in the germ and aleurone layers of grains but it is found in large quantities in pork, beef, bananas, chickpeas, and potatoes. The deficiency of this vitamin is expressed as a seborrhoeic dermatitis-like eruption with other symptoms like confusion and neuropathy.
Vitamin B7 or biotin, is also called vitamin H. It is instrumental in cell growth, production of fatty acids, and the metabolism of fats and amino acids. It helps in the metabolic reactions that involve carbon dioxide transfer, and may be helpful in maintaining normal blood sugar levels. Its deficiency is rare but the improper metabolism of this vitamin can lead to metabolic disorders. Sources of vitamin B7 include raw egg yolk, green leafy vegetables, peanuts, Swiss chard, and fish like salmon and sardine.
Vitamin B9 is known as folic acid or folate. It is instrumental in DNA synthesis and repair and serves as a co-factor in certain biological reactions. It helps in rapid cell division and growth and in the production of healthy red blood cells. Dark green vegetables, citrus fruits, beans, peas, lentils, avocado, cauliflower, and nuts are among the good sources of this vitamin. Its deficiency can lead to neural tube defects in developing embryos. Other symptoms of vitamin B9 deficiency include diarrhea, weakness, limb numbness, confusion, cognitive deficits, and irritability.
Vitamin B12, also called cobalamin is instrumental in the normal functioning of the nervous system and in the formation of red blood cells. It is the largest and the most structurally complicated vitamin. Its sources include animal-derived foods like milk, fish, poultry, and eggs. In less severe cases of the deficiency of this vitamin, one may experience fatigue and depression. It can also lead to mania and psychosis. In severe cases, the deficiency can lead to irreversible damage to the nervous system.
Vitamin C is an antioxidant. It helps maintain healthy gums and teeth. It increases the absorption of iron in the body and helps fight infections. It protects against immune system deficiencies. Citrus fruits, cabbage, pineapples, and broccoli are rich sources of vitamin C. Bleeding gums, nosebleeds, a dry, rough and scaly skin are among the common symptoms of vitamin C deficiency. In severe cases, it leads to scurvy.
Vitamin D helps in the absorption of calcium and phosphate and plays a vital role in the health of bones and teeth. Sunlight is the richest source of this vitamin. Cheese, liver, and salmon are some other sources. The symptoms of vitamin D deficiency include pain in the bones and weakness. A severe form of deficiency is expressed as a disease called rickets in which the bone tissue does not mineralize properly, leading to soft bones and skeletal deformities.
Vitamin E has antioxidant properties and it helps prevent the destruction of vitamins A and C. It protects the body from damage caused by free radicals. It protects lipids and prevents the oxidation of polyunsaturated fatty acids. It plays a role in gene expression and enzymatic activity regulation. It is also instrumental in neurological functions. Wheat germ, avocados, almonds, peanuts, and green leafy vegetables are good sources of vitamin E.
The synthesis of proteins in plasma, bones, and kidneys is brought about by vitamin K. It is also necessary for normal clotting of blood. Spinach, lettuce, cabbage, and cauliflower are sources of this vitamin. Bruising, oozing of blood at surgical sites, stomach pain, and risk of bleeding are among the symptoms of vitamin K deficiency.
Oyster shell is a natural source of minerals. Iodized salt is an example of a mineral added as a supplement. Calcium, magnesium, and phosphorous, helpful in the growth and health of bones are some of the essential minerals. Sodium, potassium, iodine as also iron and zinc are other useful dietary minerals.
Proteins are often known as the building blocks of the body. The amino acids that they contain form the structural elements of the body. Proteins are particularly needed during one’s growth period. Meat, grains, eggs, and milk are rich in protein.
The indigestible portion of plant food constitutes dietary fibers. They ease the defecation process. They provide the body with roughage, which plays a major role in the process of digestion. Whole grain food, bran, and celery are fiber-rich.
We all know that 70% of the human body is water. This fact is sufficient to illustrate the importance of water as a basic nutrient. The human body needs around 1-5 liters of water everyday. The need of water depends on the physical activity of every individual. Water prevents dehydration. Water-soluble vitamins need it. It helps in the formation of lubricants in the body. It plays an important role in the transport of nutrients in the body and the removal of waste products from it. It is used in all the cells, organs, and tissues to aid temperature regulation, to cleanse the body, and maintain bodily functions.
Proper nutrition is the key to maintain an optimal state of health. The right food consumed in the right quantities helps us lead a healthy and a happy life.