Vitamins are natural substances found in plants and animals and known as Essential nutrients for human beings. The name vitamin is obtained from "vital amines" as it was originally thought that these substances were all amines. Human body uses these substances to stay healthy and support its many functions. There are two types of vitamins: water-soluble and fat-soluble.
The body needs vitamins to stay healthy and a varied diet usually gives you all the vitamins you need. Vitamins do not provide energy (calories) directly, but they do help regulate energy-producing processes. With the exception of vitamin D and K, vitamins cannot be synthesized by the human body and must be obtained from the diet. Vitamins have to come from food because they are not manufactured or formed by the body.
There are 13 essential vitamins and each one has a special role to play within the body, helping to regulate the processes such as cell growth and repair, reproduction and digestion.
They are vitamins A, C, D, E, K and the B vitamins (thiamine, riboflavin, niacin, pantothenic acid, biotin, vitamin B-6, vitamin B-12 and folate). You can usually get all your vitamins from the foods you eat. Your body can also make vitamins D and K. People who eat a vegetarian diet may need to take a vitamin B12 supplement.
Vitamin A is important for vision, reproductive function, and normal cell reproduction. Beta-carotene, a precursor to Vitamin A, helps to fight disease-causing free radicals. Vitamin A is found in milk products, organ meats, and fish oils. Beta-carotene is found in colorful vegetables, such as carrots, broccoli, spinach, and sweet potatoes.
Vitamin B-1 (thiamin) processes carbohydrates into energy and is necessary for nerve cell function. Breads and cereals are often fortified with thiamin, though it is also found in whole grains, fish, lean meats, and dried beans.
Vitamin B-2 (riboflavin) helps the production of red blood cells and is important for growth.
Vitamin B-3 (niacin) helps control cholesterol, processes alcohol, maintains healthy skin, and converts carbohydrates to energy.
Vitamin B-5 (pantothenic acid) serves several bodily functions, such as converting fats to energy and synthesizing cholesterol.
Vitamin B-6 (pyridoxine) is important in the production of hormones such as serotonin, dopamine, and melatonin, as well as for processing amino acids.
Vitamin B-12 is a crucial component of DNA replication and nerve cell regulation. It is found in milk products, poultry, meat, and shellfish.
Vitamin C is important in wound healing and acts as an antioxidant. It also helps the body absorb iron. It's found in citrus fruits, potatoes, and greens.
Vitamin D helps the body absorb calcium, which creates healthy bones and teeth. The body can synthesize Vitamin D after exposure to sunshine, but it can also be found in fortified milk products and cereals, as well as in fish.
Vitamin E helps to combat free radicals, which can damage our cells. It's found in nuts and seeds, green leafy vegetables, corn, asparagus, and wheat germ.
Vitamin K is what makes the blot clot. While our bodies produce some Vitamin K, it can also be found in vegetables like cauliflower and cabbage.
1. A lot of the vitamins in fruits and vegetables are lost between the farm and your plate. The longer the foods are stored before you eat them, the more nutrients are lost. Heat, light, and exposure to air all reduce the amount of vitamins, especially Vitamin C, thiamin, and folic acid.
2. About 25% of US households do not have balanced meals to meet the requirements that the body needs in digesting enough nutrients to sustain the body's health and fuel factors.
3. Research has shown that almost all varieties of disease can be produced by the deficiency of vitamins, minerals, amino acids, and other nutrients. Vitamins are vital for your skin. The most important factor of nutritional deficiencies is the intense processing and refining of foods like cereals and sugar.
4. The human body uses food to manufacture all its building blocks as well as to provide fuel. To do this, it performs several thousand different chemical reactions. Each reaction is controlled by "enzymes" and "coenzymes". Some of the coenzymes contain vitamins which the body cannot make by itself and which must be obtained from outside the body.
Types of Vitamins.
Vitamins, one of the most essential nutrients required by the body and can be broadly classified into two main categories by the substance that carries them throughout the body. i.e., water-soluble vitamins (vitamins that wash away) and fat-soluble vitamins (vitamins that build up).
Water-soluble vitamins cannot be stored in the body, so you need to get them from food every day. They can be destroyed by overcooking. These are easily absorbed by the body. Human body doesn't store large amounts of water-soluble vitamins. B-complex vitamins and vitamin C are water-soluble vitamins that are not stored in the body and must be replaced each day. These vitamins are easily destroyed or washed out during food storage and preparation. They are eliminated in urine so, body need a continuous supply of them in diets.
Proper storage and preparation of food can minimize vitamin loss. To reduce vitamin loss, refrigerate fresh produce, keep milk and grains away from strong light, and use the cooking water from vegetables to prepare soups. An excess of water soluble vitamins should not result in any side effects as they will disperse in the body fluids and voided in the urine.
Nine of the water-soluble vitamins are known as the B-complex group: Thiamin (vitamin B1), Riboflavin (vitamin B2), Niacin, Vitamin B6, Folate, Vitamin B12, Biotin, Pantothenic acid and Vitamin C. These vitamins are widely distributed in foods.
The fat-soluble vitamins include vitamins A, D, E and K - since they are soluble in fat and are absorbed by the body from the intestinal tract. The human body has to use bile acids to absorb fat-soluble vitamins. Once these vitamins are absorbed, the body stores them in body fat. When you need them, your body takes them out of storage to be used. Eating fats or oils that are not digested can cause shortages of fat-soluble vitamins.
Fat soluble vitamins should not be consumed in excess as they are stored in the body and an excess can result in side effects. An excess of vitamin A may result in irritability, weight loss, dry itchy skin in children and nausea, headache, diarrhea in adults.
Characteristics of the vitamins are:
1. Most of the vitamins have been artificially synthesized.
2. Some of vitamins are soluble in water and others are fat-soluble.
3. Some vitamins are synthesized in the body. Some members of vitamin B complex are synthesized by microorganisms in the intestinal tract.
4. Vitamins are partly destroyed and are partly excreted.
5. Vitamins can be stored in the body to some extent, for example the fat-soluble vitamins are stored in the liver and subcutaneous tissue.
6. Vitamins can perform their work in very small quantities. Hence, the total daily requirement is usually very small.
Deficiencies of vitamins are classified as either primary or secondary.
A primary deficiency occurs when an organism does not get enough of the vitamin in its food. A secondary deficiency may be due to an underlying disorder that prevents or limits the absorption or use of the vitamin, due to a “lifestyle factor”, such as smoking, excessive alcohol consumption, or the use of medications that interfere with the absorption or use of the vitamin. People who eat a varied diet are unlikely to develop a severe primary vitamin deficiency. In contrast, restrictive diets have the potential to cause prolonged vitamin deficits, which may result in often painful and potentially deadly diseases.
Dietary supplements, often containing vitamins, are used to ensure that adequate amounts of nutrients are obtained on a daily basis, if optimal amounts of the nutrients cannot be obtained through a varied diet. Scientific evidence supporting the benefits of some dietary supplements is well established for certain health conditions, but others need further study.
Why They Matter.
Vitamins and minerals are substances your body needs for normal growth and functioning. Some facilitate crucial chemical reactions, while others act as building blocks for the body.
Nutritionists call vitamins and minerals "micronutrients" to distinguish them from the macronutrients such as proteins, carbohydrates, and fats that make up the bulk of our food. While micronutrients are vital for the proper processing of macronutrients, they're needed in smaller quantities. Think of it this way: If macronutrients are the gas in your engine, then micronutrients are like the motor oil, coolant, and battery fluid.
Micronutrient deficiency can lead to acute diseases with exotic names like scurvy, pellagra, and beriberi. Deficiency diseases were common in the U.S. until the 1940s, when the FDA-mandated fortification of common foods like bread and milk. These diseases are still common in many poorer countries.
If you don't eat a nutritious variety of foods, some supplements might help you get adequate amounts of essential nutrients. However, supplements can't take the place of the variety of foods that are important to a healthy diet. Good sources of information on eating well include the Dietary Guidelines for Americans and MyPlate. However, for those not eating properly, supplementation is better than nothing.