Vitamins are divided into two classes based on their solubility. The the fat-soluble vitamins include vitamin D, Vitamin E, vitamin A, and vitamin K. The water-soluble vitamins are folate (folic acid), vitamin B12, biotin, vitamin B6, niacin, thiamin, riboflavin, pantothenic acid, and vitamin C (ascorbic acid). Fat-soluble vitamins contain only carbon, hydrogen, and oxygen while water-soluble vitamins contain these three elements plus nitrogen and some-times sulfur. Fat-soluble vitamins can be stored in appreciable amounts in the body and the water-soluble vitamins cannot be stored in the body.
Vitamins are necessary in small amounts for normal metabolism and good health. Vitamins and minerals have no calories and are not an energy source, but assist in metabolizing nutrients in food and are invaluable in keeping your body running smoothly. Vitamins make it possible for other nutrients to be digested, absorbed and metabolized by the body. Vitamins are sometimes referred to as the "spark plugs" of our human machine. They are required to do many things and their excess or depletion can lead to acute and chronic disease.
Fat Soluble Vitamins:Vitamin A - Vitamin A is the collective name for a group of fat-soluble vitamins. The most usable form of the vitamin is retinol. Vitamin A palmitate (retinyl palmitate) and vitamin A acetate (retinyl acetate) are the principal forms used as nutritional supplements. The precursors of vitamin A (retinol) are the carotenoids (most commonly beta-carotene). Vitamin A is one of the most versatile vitamins, with roles in such diverse functions as vision, immune defenses, maintenance of body linings and skin, bone and body growth, normal cell development, and reproduction.
Vitamin D - Vitamin D actually refers to a group of steroid molecules. Vitamin D is called the sunlight vitamin because the body produces it when the sun's ultraviolet B (UVB) rays strike the skin. Vitamin D is important for the proper absorption of calcium from food. It is vital for the control of the levels of calcium in the blood and also controls the rate at which the body excretes calcium in the urine. Low levels of vitamin D and insufficient sunlight exposure are associated with osteoporosis. Maintaining sufficient vitamin D levels may help decrease the risk of several autoimmune diseases.
Vitamin E - Vitamin E is actually an umbrella term for a group of compounds called tocopherols and tocotrienols. Alpha-tocopherol is the name of the most active form of vitamin E in humans. Vitamin E is one of the many nutrients that have protective properties. The main function of vitamin E is to maintain the integrity of the body's intracellular membrane by protecting its physical stability and providing a defense line against tissue damage caused by oxidation. Vitamin E is an antioxidant that prevents free radical damage in biological membranes.
Vitamin K - Vitamin K is a group of 2-methilo-naphthoquinone derivatives. Vitamin K is involved in the carboxylation of certain glutamate residues in proteins to form gamma-carboxyglutamate residues. Vitamin K plays an important role in blood clotting and bone metabolism (carboxylation of osteocalcin). Vitamin K supplements may improve bone mass in postmenopausal women. Vitamin K is used to reduce risk of bleeding in liver disease, jaundice, malabsorption, or in association with long-term use of aspirin or antibiotics.
Water Soluble Vitamins:
Vitamin B1 (thiamine) - Vitamin b1 is absolutely essential to several bodily functions. Thiamine is a coenzyme for the decarboxylation of pyruvate and the oxidation of alpha keto-glutamic acid. Thiamine
Water Soluble Vitamins:
Vitamin B1 (thiamine) - Vitamin b1 is absolutely essential to several bodily functions. Thiamine is a coenzyme for the decarboxylation of pyruvate and the oxidation of alpha keto-glutamic acid. Thiamine
Vitamin B2 (riboflavin) - Riboflavin or vitamin B2 is an essential nutrient in human nutrition and plays a key role in the production of energy. Vitamin B2 is an intermediary the transfer of electrons in the cellular oxidation-reduction reactions which generate energy from protein, carbohydrate and fat. Vitamin B2 helps prevent and is used to treat migraine headaches, cataracts, rheumatoid arthritis, and a number of skin disorders such as acne (acne rosacea), dermatitis, and eczema.
Vitamin B3 (niacin) - Vitamin B3 is also known as niacin, nicotinic acid, nicotinamide, niacinamide and antipellagra vitamin or PP factor. Vitamin B3 is essential in the metabolism of carbohydrates (to produce energy), fats, and proteins. It also aids in the production of hydrochloric acid, needed for proper digestion. Nicotinic acid, in pharmacological doses, is used as an antihyperlipidemic agent. Niacinamide is used to treat osteoarthritis, rheumatoid arthritis, insomnia, migraine headaches, and insulin-dependent diabetes.
Vitamin B6 (pyridoxine) - Vitamin B6 (pyridoxine) serves as coenzyme and is involved in the metabolism of protein and carbohydrates, the production of insulin and red and white blood cells, and the synthesis of neurotransmitters, enzymes, and prostaglandins. Vitamin B6 is a coenzyme for several enzyme systems. Vitamin B6, used mainly in the body for the processing of amino acids, performs this task along with certain enzymes. Vitamin B6 is required for the production of serotonin and helps to maintain healthy immune system functions.
Pantothenic acid (vitamin B5) - Pantothenic acid is an antioxidant water-soluble vitamin needed to break down carbohydrates, proteins, and fats. Pantothenic acid comes in two forms: calcium pantothenate and pantethine. Vitamin B5 is essential for human growth, reproduction and many normal bodily processes. Vitamin B5 helps metabolize nutrients, manufacture antibodies and produce vitamin D. Pantothenic acid plays a role in the synthesis of hemoglobin, steroid hormones, neurotransmitters, and lipids.
Biotin (vitamin H, vitamin B7) - Biotin is of great importance for the biochemistry of the human organism. Biotin helps in the synthesis of fatty acids, in energy metabolism, and in the synthesis of amino acids and glucose. Biotin serves as an essential coenzyme for four carboxylase enzymes, each of which is important in metabolism. Biotin is an important vitamin for helping certain enzymes in the body. The primary role of biotin is in the metabolism of fats, proteins and carbohydrates.
Folic acid (folate, vitamin B9) - Folate and folic acid are forms of a water-soluble B vitamin. Folic acid is a synthetic folate form which is used for food fortification and nutritional supplements. Folic acid plays an essential role in human growth and development, in particular cell division and DNA synthesis. Folic acid is important for any stage of human life which involves growth such as pregnancy, lactation and early growth because of the role the folate plays in DNA, RNA and protein production.
Vitamin C (ascorbic acid) - Vitamin C, also known as ascorbic acid is a water-soluble vitamin that is an essential part of life. Vitamin C is perhaps the most popular vitamin among the common nutrients and biochemicals. Ascorbic acid and its sodium, potassium, and calcium salts are commonly used as antioxidant food additives. The body requires vitamin C to form and maintain bones, blood vessels, and skin. Vitamin C is responsible for helping to build and maintain our tissues and strengthening our immune system.
Sources of Vitamins:
Most of the vitamins can be found in plant and animal sources. They can also be chemically synthesized. Vitamin A occurs in nature in two forms: preformed vitamin A and provitamin A, or carotene. The vegetable sources of beta-carotene are fat and cholesterol free. Thiamine (vitamin B1) is found in fortified breads, cereals, pasta, whole grains, lean meats (especially pork), fish, dried beans, peas, and soybeans. Sources of riboflavin include organ meats (liver, kidney, and heart) and certain plants such as almonds, mushrooms, whole grain, soybeans, and green leafy vegetables. Niacin is found in dairy products, poultry, fish, lean meats, nuts, and eggs. Vitamin B4 (adenine) is found in brewer's yeast, whole grains, raw unadulterated honey, bee pollen, royal jelly, propolis, most fresh vegetables, most fresh fruits. Common sources of pantothenic acid are cheese, corn, eggs, liver, meats, peanuts, peas soybeans, brewer's yeast, and wheat germ. Foods rich in vitamin B6 include white meat (poultry and fish), bananas, liver, whole-grain breads and cereals, soybeans and vegetables. Beans, leafy green vegetables, citrus fruits, beets, wheat germ, and meat are good sources of folic acid. Vitamin B12 is found naturally in food sources in protein-bound forms.
Good sources of orotic acid are root vegetables and whey. Pangamic acid is found in whole grains such as brown rice, brewer's yeast, pumpkin and sunflower seeds, and beef blood. Vitamin B17 is found in most all fruit seeds such as the apple, peach, cherry, orange, plums, nectarine and apricot. Inositol is available from both plant and animal sources. Dietary sources of carnitine include foods of animal origin. Natural sources of PABA include bran, eggs, kidney, liver, molasses, wheat germ, brewer's yeast, and yogurt. Good dietary sources of biotin include organ meats, oatmeal, egg yolk, soy, mushrooms, bananas, peanuts, and brewer's yeast. Cabbage and many dark green leafy vegetables are all good sources of vitamin C. Exposure to sunlight is an important source of vitamin D. Good food sources of vitamin D include milk, fatty fish. Vitamin E is found in the germ of a seed or grain. Alpha-lipoic acid is mainly derived from dietary sources. Rich sources of vitamin K include broccoli, Brussels sprouts, cabbage, cauliflower, kale, spinach and soybeans. Bioflavonoids are abundant in the pulp and rinds of citrus fruits and other foods containing vitamin C. Coenzyme Q10 is found in the membranes of endoplasmic reticulum, peroxisomes, lysosomes, vesicles and notably the inner membrane of the mitochondrion.Sources of Vitamins:
Most of the vitamins can be found in plant and animal sources. They can also be chemically synthesized. Vitamin A occurs in nature in two forms: preformed vitamin A and provitamin A, or carotene. The vegetable sources of beta-carotene are fat and cholesterol free. Thiamine (vitamin B1) is found in fortified breads, cereals, pasta, whole grains, lean meats (especially pork), fish, dried beans, peas, and soybeans. Sources of riboflavin include organ meats (liver, kidney, and heart) and certain plants such as almonds, mushrooms, whole grain, soybeans, and green leafy vegetables. Niacin is found in dairy products, poultry, fish, lean meats, nuts, and eggs. Vitamin B4 (adenine) is found in brewer's yeast, whole grains, raw unadulterated honey, bee pollen, royal jelly, propolis, most fresh vegetables, most fresh fruits. Common sources of pantothenic acid are cheese, corn, eggs, liver, meats, peanuts, peas soybeans, brewer's yeast, and wheat germ. Foods rich in vitamin B6 include white meat (poultry and fish), bananas, liver, whole-grain breads and cereals, soybeans and vegetables. Beans, leafy green vegetables, citrus fruits, beets, wheat germ, and meat are good sources of folic acid. Vitamin B12 is found naturally in food sources in protein-bound forms.
Vitamin recommended dietary allowance:
Insufficient vitamin intake will lead to a number of vitamin deficiency diseases. However, high doses of vitamins should be regarded as drugs rather than supplements, which will causes some potential health risks. To keep people informed of the correct nutrition intake, the Food and Nutrition Board of the National Academy of Sciences/National Research Council publishes the Recommended Daily Allowances (RDA) for vitamins and other nutritional supplements based on scientific researches and clinical findings. The amounts of nutrients and calories an individual is recommended to consume daily to maintain good health for the majority of populations. The Dietary Reference Intakes (DRIs) are a comprehensive set of nutrient reference values for healthy populations that can be used for assessing and planning diets. DRIs replace previously published Recommended Nutrient Intakes (RNIs). Estimated Average Requirement (EAR) is the average daily nutrient intake level estimated to meet the requirement of half the healthy individuals in a particular life stage and gender group. Recommended Dietary Allowance (RDA) is the average daily dietary nutrient intake level sufficient to meet the nutrient require- ment of nearly all (97 to 98 percent) healthy individuals in a particular life stage and gender group. Adequate Intake (AI) is the recommended average daily intake level based on observed or experimentally determined approximations or estimates of nutrient intake by a group (or groups) of apparently healthy people that are assumed to be adequate - used when an RDA cannot be determined. Tolerable Upper Intake Level (UL) is the highest average daily intake level that is likely to pose no risk of adverse health effects to almost all individuals in the general population. As intake increases above the UL, the potential risk of adverse effects may increase.
