The term vitamin derives from experiments conducted early in this century, which indicated that proper nutrition was dependent upon introduction of one or several vital nitrogen-containing amines into the diet.
Vitamins are organic molecules (not necessarily amines) that are essential to metabolism in all living organisms. While these molecules serve essentially the same role in all forms of life, higher organisms have lost the ability to synthesize vitamins. There are two major groups of vitamins: the fat-soluble vitamins designated by the letters A, D, E, and K, and the water-soluble vitamins, which are referred to as the vitamin B complex. Most vitamins are converted in vivo into coenzymes that work with metabolic enzymes to complete their biochemical functions. A lack of proper amounts of vitamins in the diet leads to a host of vitamin-deficiency diseases.
Adenine (Vitamin B-4) – Purine that is definitely not a vitamin.
Early studies of chicks and rats that were fed autoclaved cereals without nutritional supplements, indicated that these animals exhibited retarded growth and developed general muscular weakness leading to paralysis. Dr. V. Reader isolated a factor from both yeast and liver that alleviated these symptoms, and he later termed the factor vitamin B-4. This vitamin was determined to be adenine, the purine present as a nucleotide base in both DNA and RNA. However, subsequent investigations indicated that the addition of adenine to the deprived animals' diet did not alleviate the retarded growth and paralysis symptoms. Later, workers found that thiamine (vitamin B-1) cured the symptoms and it is now generally agreed that adenine does not possess any vitamin properties. In fact, the human body has a number of complicated pathways to produce adenine, and this substance is definitely not required as a dietary supplement.
The term vitamin derives from experiments conducted early in the twentieth century, which indicated that proper nutrition was dependent upon introduction of one or several nitrogen-containing amines into the diet. Considered vital to life, these amines were dubbed “vitamines” by Polish scientist Casimir Funk, and the term was soon applied to all organic molecules that are essential to metabolism in living organisms. When it was later realized, however, that not all of these organic molecules contain amines, the letter “e” was dropped from the word, which was already in widespread use. Vitamins serve essentially the same role in all forms of life, but higher organisms have lost the ability to synthesize the molecules (or to synthesize them in adequate amounts) and must consume them in small quantities in the diet. This necessity has come to be included as part of the presiding definition of a vitamin, and many molecules that are necessary for proper health and were once considered vitamins, are no longer classed as such since they may be synthesized in sufficient quantities by the body.
Amygdalin (Vitamin B-17, Laetrile) – Anticancer agent and vitamin–not!
Amygdalin is a naturally occurring glycoside that was originally isolated from apricot pits by the famous biochemist Forest T. Krebs in the 1920s. Other sources include the seeds and pits of apples, cherries, peaches, plums, almonds, papaya, and nectarines. An unusual feature of this carbohydrate is the presence of a cyanide substituent that yields HCN upon hydrolysis by intestinal bacteria. The more common name for amygdalin is "laetrile" and many investigations have been conducted to determine the potential anti-cancer activity of amygdalin. For the most part, it has been found that amygdalin is devoid of any significant activity against tumor cells and can be lethal if ingested in excessive amounts. Ernst Krebs conducted many of the anti-cancer studies of amygdalin and he ultimately named the compound vitamin B-17, although there is no established metabolic need for amygdalin and none of the common vitamin deficiency symptoms occur when this chemical is excluded from the diet of humans.
There are two major groups of vitamins: the fat-soluble vitamins designated by the letters A, D, E, and K, and the water-soluble vitamins which include vitamin C and the group of molecules referred to as the vitamin B complex. Members of both groups are absorbed in the human body through the intestines, but the fat-soluble vitamins are transported to other areas via the lymph system while water-soluble vitamins are conveyed to tissues via the circulatory system. Storage of the vitamins also differs, fat-soluble varieties remaining in the body for longer periods of time since the molecules may be stored in the liver, in fat, and, in some cases, organs of the reproductive system. Water-soluble vitamins, however, are only stored in the body in trace amounts, and it is, therefore, not believed to be beneficial to consume excessive amounts of the substances. Indeed, most of the surplus of a water-soluble vitamin exits the body in urine, resulting in the need of consuming the same vitamin on a daily basis in order to maintain sufficient quantities.
Anthranilic Acid (Vitamin L) – A factor originally thought to be important for lactation.
In the 1930s a group of Japanese researchers led by Dr. W. Nakahara isolated two distinct factors that were reported to be essential for lactation in the rat. They coined the term "Vitamin L" for these factors and proposed that they were essential for proper metabolism in humans. Subsequent studies indicated that factor L(1), extracted from bovine (calf) liver, was anthranilic acid. The second factor, L(2), was extracted from yeast and shown to be adenylthiomethylpentose. Later studies have confirmed that neither of these factors are essential to lactation either in rats or in humans. There are no proven symptoms from dietary deficiencies of either of these biochemicals.
Vitamins, which may be consumed from a wide range of sources, are important to the human body in a variety of ways. One of the main roles of vitamins is to act as enzymes, or coenzymes that work with other metabolic enzymes, to catalyze and aid in the completion of biochemical reactions. The specific reactions involved, however, are vitamin dependent, each molecule being associated with certain kinds of activities. Vitamin B1, for instance, is associated with the metabolism of carbohydrates, fats, and proteins, while vitamin B12 is believed to facilitate red blood cell production in humans and other higher animals. Some of the other aspects of health that vitamins are concerned in include the formation of proteins crucial for blood clotting (vitamin K), inhibition of oxidation in body tissues (vitamin E), and the production of collagen (vitamin C).
Ascorbic Acid (Vitamin C) – One of the most ubiquitous vitamins ever discovered.
Vitamin C is one of the most ubiquitous vitamins ever discovered. Besides playing a paramount role as an anti-oxidant and free radical scavenger, it has been suggested to be an effective antiviral agent by some very respected scientists. Although the antiviral properties of vitamin C remain the subject of great debate in some circles, this water-soluble vitamin remains one of the most popular and important vitamins. Vitamin C is commonly found naturally in peppers, citrus fruits, tomatoes, melons, broccoli, and green leafy vegetables such as spinach, turnip, and mustard greens. The primary function of vitamin C is to assist in the production of collagen, although it is rapidly becoming identified as a key player in detoxifying the body from foreign substances. Although there is somewhat limited documentation, other reported uses of vitamin C are healing wounds and burns, accelerate healing after surgery, decreasing blood cholesterol, reduce blood clotting, offer protection against cancer agents, and extend life. Many of these reputed uses are highly speculative and lack the proper scientific verification.
Vitamin C is perhaps the most popular vitamin among the common nutrients and biochemicals. Because the vitamin is water-soluble, it must be regularly replenished and is commonly found in fresh fruits, especially in the citrus family that is dominated by oranges, lemons, limes, and tangerines. Vitamin C (commonly referred to as ascorbic acid) is also abundant in green leafy vegetables. One of the prime responsibilities of ascorbic acid is to assist in the production of collagen, the principal protein used to synthesize connective tissue that is essential to skin, bone, and cartilage formation. Vitamin C accomplishes this task by helping the body utilize such nutrients as carbohydrates, fats, and proteins. More Important, ascorbic acid is recognized as a potent anti-oxidant, helping to protect cells from damage by free radicals. The biochemical is also essential for wound healing and in strengthening blood vessel walls. Among the many sources of vitamin C are grapefruits, melons, papaya, cabbage, strawberries, broccoli, winter squash and raspberries.
The term "vitamin" is derived from the Latin word vita meaning life, and describes a class of nutrients that regulate important metabolic reactions. Collectively, vitamins assist in the formation of a wide spectrum of biochemicals including hormones, enzymes, proteins, neurotransmitters, and the genetic materials RNA and DNA. Although these organic nutrients are generally not structurally related to each other, they all promote metabolic balance within cells, ensuring that important biochemical reactions proceed as required. Many vitamins combine with proteins to create enzymes (termed co-enzymes) that mediate chemical reactions occurring within the body. Vitamins are divided into two categories, one of which is commonly known as fat soluble and includes vitamins A, D, E, and K. The other, water soluble, vitamin category includes the B-vitamin complex and vitamin C. Both of these vitamins must frequently be replenished because they are not stored in body tissue, and are usually rapidly excreted with urine. Vitamin C, or ascorbic acid, is necessary for a wide range of biochemical reactions and its antioxidant properties are vital to several key metabolic pathways.
Soluble ascorbic acid is largely confined to the watery parts of fruits and vegetables and represents one of the least chemically stable molecules in the vitamin family. This weak acid is easily destroyed by mild alkali solutions such as baking soda. Once ingested, vitamin C is readily absorbed by the intestines and continues its journey through the watery components of tissues that make up the human body, helping to build collagen protein while doubling as an antioxidant along the way.
Ascorbic acid is a fragile molecule that is easily destroyed in neutral or alkaline solutions, at elevated temperatures, and upon exposure to oxygen. The vitamin C structure is freely soluble in water, less so in alcohol, and insoluble in certain chemicals such as chloroform, ether, and benzene. In its natural state, ascorbic acid appears in the form of a white to yellowish crystal or powder. The chemical name ascorbic acid refers to L-ascorbic acid, the levorotatory isomer, and has been widely synthesized as a supplement or food additive. Fruits and vegetables are rich natural sources, however the vitamin C content can be rapidly depleted as food becomes stale or when the labile biochemical leaches into water during cooking. The photomicrograph presented above was made with vitamin C recrystallized from the melt and has been titled: Vitamin C Horse.
One of the oldest known medical texts, the Ebers Papyrus of Ancient Egypt, describes symptoms associated with eating inadequate quantities of foods that are rich in vitamin C (ascorbic acid). The condition is called scurvy, and the symptoms include swollen gums, loose teeth, black-and-blue spots or open sores on the skin, and slow wound healing. The disease was especially prevalent in seamen on long sea voyages during the sixteenth and seventeenth centuries who primarily ate nonperishable foods that lacked this essential vitamin. Relief from scurvy finally came about when the curative properties of ascorbic acid-containing citruses were discovered in 1747 by the Scottish naval surgeon, James Lind. Naturally abundant in many fruits and vegetables, vitamin C is especially rich in citrus fruits such as oranges, lemons, tangerines, and limes. Although treatment with ascorbic acid usually achieves a quick recovery from the effects of scurvy, not all damage is reversible, especially that occurring in non-regenerative tissues such as eye cornea, nerve tissue, and calcified bone. Today, advanced techniques that help preserve freshness and the availablility of a large variety of vitamin C-rich foods have almost eradicated this disease.
Vitamin C is so often found in sources of fresh fruits and vegetables that it is called ubiquitous, yet many details concerning how the vitamin precisely affects metabolism remain elusive. Described as a carbohydrate-like substance, vitamin C or ascorbic acid is essential to the synthesis of collagen, a protein important in the formation of healthy skin, teeth, and bones. Being a relatively strong reducing agent, this nutrient's reputation as a key in vivo antioxidant is well established. Although there is no question that the biochemical is essential to life, scientists are in considerable debate over the extent of vitamin C's influence in such arenas as lowering blood cholesterol, combating viruses and the common cold, and protecting against cancer-causing agents. Some of the scientific evidence seems to suggest that ascorbic acid helps prevent formation of carcinogenic compounds called nitrosamines that can be produced in the stomach when eating a meal of smoked, processed, or preserved meats such as bacon, sausage, ham, and hot dogs. Interestingly, many Old World European recipes have, for centuries, combined cured meats with such vitamin C rich fruits and vegetables as stewed apples, baked tomatoes, and/or onions.
Vitamin C has a simple chemical structure, yet this nutrient has an important role in intracellular formation of the body's most abundant protein, termed collagen. Collagen provides the foundation upon which tendons, ligaments, skin, and bones are formed. The water-soluble vitamin fulfills its role by hydroxylating proline and lysine, two amino acids that are indispensable to the body's production of healthy tissue, in a process called oxidation-reduction or redox. The vitamin C deficiency disease, scurvy, results when the body is unable to hydroxylate proline due to an inadequate supply of vitamin C. The affliction, which results from weakened collagen fibers, is manifested in rotting teeth, slow healing, and open sores on the skin. Many scurvy symptoms can be corrected by proper intake of ascorbic acid. As a relatively strong reducing agent, this water-soluble vitamin also serves as an anti-oxidant to protect cells from damage by free radicals. Some plants and animals are able to produce their own ascorbic acid because they have a cascade of enzymes that can transform glucose into ascorbic acid when needed. Interestingly, somewhere in the chain of evolution, humans either lost or never developed the enzymes that that can manufacture vitamin C, and therefore are dependent on dietary intake of ascorbic acid.
Vitamin C is found in a wide spectrum of popular foods, but occurs most commonly in citrus fruits such as lemons, limes, and grapefruits, as well as tomatoes. The sugar-like vitamin easily oxidizes in air and is sensitive to both light and heat. Ascorbic acid is a relatively fragile molecule and may be lost from foods during preparation, cooking, and/or storage. In spite of the fact that vitamin C is easily destroyed, it has the ability to preserve foods by virtue of its role as a reducing agent. Leafy greens such as collards, spinach, and turnip greens are good sources of needed vitamin C in either raw or cooked forms. Most foods, however, yield maximum amounts of ascorbic acid when eaten raw or minimally cooked. Other good food sources of vitamin C include rosehips, strawberries, watercress, papaya, and mangos. Potatoes and green vegetables such as broccoli, brussel sprouts, and cabbage also provide this essential nutrient. In addition to natural sources, vitamin C may be obtained in synthetic derivatives of glucose. Supplemental forms include tablets, capsules, powdered crystalline, and liquid forms.
Many plants and most animals, including reptiles, do not need to consume ascorbic acid rich foods and are instead genetically programmed to produce enzymes that convert glucose into vitamin C. Mammals, in particular, possess the L-gulonolactone oxidase enzyme, enabling them to manufacture ascorbic acid from blood glucose in a metabolic cascade of enzymatic action. Curiously, however, the only way that humans, guinea pigs, and several primate species can satisfy their ascorbic acid requirements is to obtain the vitamin in their diets. As it happens, although humans have three essential enzymes required to convert glucose into ascorbic acid, they lack the fourth and final enzyme needed to complete the biochemical pathway.
Some scientists believe that naturally occurring bioflavinoids increase the influence of ascorbic acid on good health. Flavinoids are, in essence, plant pigments largely responsible for the colors of many fruits and vegetables that often contain large quantities of vitamin C. Over 4,000 flavinoid-type compounds have been identified and classified according to chemical structure. Some of the better-established citrus flavinoids include rutin, hesperidin, and quercitin, which function to increase capillary permeability. The scientist who discovered both vitamin C and the first flavinoids, Dr. Albert Szent-Gyorgyi, received a Nobel Prize for his research relating to these substances.
The Recommended Dietary Allowance (RDA) is a benchmark for nutritionally well-balanced diets, which was originally developed to ensure that World War II soldiers received proper types of food for maintaining good health. Designed to protect people against possible nutrient deficiencies, the RDA sets minimum dietary requirements of nutrient intake for average, healthy individuals. Different levels, however, may be recommended for children, the elderly, and people whose health is comprised by disease or stressed by activities such as physical exertion, smoking, and exposure to extreme environmental conditions. The Food and Nutrition Board of the National Research Council (a division of the National Academy of Sciences) is currently supplementing the RDA baseline by issuing nutrient recommendations that are based on optimizing health in individuals and certain groups. An additional indictor, Adequate Intake, has been assigned to nutrients that do not have sufficient scientific evidence to establish average requirements. Increasing interest in nutritional supplements and fortified foods has led to maximum intake indicators, which provide general guidance about possible toxic levels to healthy people in specific groupings of gender and age, called the Tolerable Upper Intake Level or ULs. Labels on packaged foods, termed the Nutrition Facts Panel, are mandatory on all processed foodstuffs and must quantitatively indicate the product's content of ascorbic acid and other vitamins.
Beta-Carotene (Vitamin A precursor) – Yellow pigment that forms vitamin A.
Beta-carotene is the pigment that gives carrots, sweet potatoes, and other yellow vegetables their characteristic coloring. This conjugated polyene also serves as a precursor that can be enzymatically converted into vitamin A in most animals and man. Although vitamin A is not present in any plants, the carotene precursor can be found in carrots, pumpkins, spinach, squash, watermelon, asparagus, broccoli, and cantaloupe. Liver is also a very good source for beta-carotene. Vitamin A (retinol) is an essential component for vision and it promotes bone growth, tooth development, and helps maintain healthy skin, hair, and mucous membranes. Deficiencies of vitamin A result in a number of maladys including night blindness, dry skin, poor bone growth, weak tooth enamel, and weight loss.
A lack of proper amounts of vitamins in the diet leads to a host of vitamin-deficiency diseases. The photomicrograph in our banner depicts crystallites of vitamin C, also known as ascorbic acid, which serves as a general reducing agent in many biochemical reactions and has been implicated by Nobel laureate Linus Pauling as a cure for the common cold. More importantly, this vitamin is necessary to ward off the disease known as scurvy, which is characterized by pronounced weakness, spongy gums, bleeding mucous membranes, and spotting of the skin caused by extravasation of blood. Awareness that the consumption of citrus fruits, which are rich in vitamin C, could ward off scurvy developed during the eighteenth century, more than a hundred years before the vitamin itself was identified. This early awareness improved the lives of many sufferers of the condition and led to the regular rations of lime juice provided for sailors of the British Royal Navy that resulted in their being dubbed “limeys.” Additional well-known diseases associated with vitamin deficiency include rickets (vitamin D), beriberi (vitamin B1), pellagra (vitamin B3), and pernicious anemia (vitamin B12), among others.
Biotin (Vitamin H) – Carbon dioxide carrier that builds fats.
Biotin is a water-soluble member of the B-complex group of vitamins and is commonly referred to as vitamin H. The biochemical acts as a carrier for carbon dioxide in the pyruvate carboxylase reaction, where biotin is linked to the epsilon-amino group of a lysine residue in the enzyme. Biotin is necessary for both metabolism and growth in humans, particularly with reference to production of fatty acids, antibodies, digestive enzymes, and in niacin (vitamin B-3) metabolism. Food sources for biotin are liver, kidney, soy flour, egg yolk, cereal, and yeast. There are suggestions that biotin is also capable of curing baldness, alleviating muscle pain and depression, and functions as a cure for dermatitis, although there is no substantial evidence for any of these claims. Biotin deficiency results in fatigue, depression, nausea, muscle pains, hair loss, and anemia.
Typically, a normal, well-balanced diet is sufficient in meeting all of the human body’s requirements for vitamins. To help ensure that consumers know exactly how balanced their food choices are, a number of different reference guides have been developed. The most familiar in the United States is the Recommended Dietary Allowance (RDA), a guideline issued by the Food and Nutrition Board of the National Academy of Sciences. RDAs may be different depending upon age and gender. A similar, but more recently developed, guideline is the Reference Daily Intake (RDI), which provides a population-adjusted average RDA based on all ages and sex groups of RDA values. Another way of expressing vitamin recommendations is through Daily Reference Values (DRV), a loose consumer guide for labeling purposes that relates suggested amounts of certain substances that a 2000-calorie diet should contain. Also frequently found on labels is the Percent of Daily Value, which relates the percentage of the total daily requirement of a vitamin or other substance provided by a single serving of the food in question.
Cholecalciferol (Vitamin D) – The vitamin made from rich sunlight.
Cholecalciferol is the most widely known of the vitamin D series and is a fat soluble vitamin that is stored to some degree in the body. Many people know that sunlight is a source of vitamin D, but this is true only in the fact that ultraviolet light from the sun acts as a catalyst on a vitamin D precursor in the skin. Vitamin D formed in this manner is termed "natural vitamin D" or vitamin D3. Vitamin D precursors obtained from milk and other products as well as sunlight-produced vitamin D must be metabolized in the liver to form the active coenzyme. The primary functions of vitamin D are stimulation of calcium and magnesium absorption, two minerals that are essential for strong bones. Sources of vitamin D include fish liver oil, butter, and milk.
Cyanocobalamin (Vitamin B-12) – A vitamin that treats pernicious anemia.
Cyanocobalamin, a synthetic derivative of vitamin B-12, is considered the most potent vitamin and is one of the last true vitamins that has been classified. Vitamin B-12 was discovered through studies of pernicious anemia, a condition that begins with a megaloblastic anemia and leads to an irreversible degeneration of the central nervous system. Scientists found that this condition could be reversed by feeding afflicted patients large amounts of raw liver. The active material in the liver was later found to be vitamin B-12, but it is present only in very small concentrations, so many years passed before enough was isolated for serious investigations. Cyanocobalamin is a very unusual biochemical that contains a tetrapyrrole ring system, called a corrin ring, that is chemically very similar to the porphyrin ring system of the heme compounds. Contained within the corrin ring, at the coordination point, is a cobalt ion that is associated with a cyanide ion and a dimethylbenzimidazole nucleotide. Vitamin B-12 functions to provide a methyl group that is used in the synthesis of a number of products during biochemical reactions. Clinically, cyanocobalamin works to promote normal growth and development, helps with certain types of nerve damage, and treats pernicious anemia. This vitamin is not available from plant sources (vegetarians beware!), but animal sources include beef, liver, blue cheese, eggs, fish, milk, and milk products. Symptoms associated with a deficiency of vitamin B-12 are primarily those of pernicious anemia.
second image of Cyanocobalamin (Vitamin B-12)
Folic Acid (Folate, Vitamin B-9) – A vitamin that helps fetus development during pregnancy.
Folic acid is a water-soluble B vitamin that takes its name from the Latin word for leaf, folium, because it was first isolated from spinach leaves. Biochemically, folic acid (or folate) functions as a methyl donor after being enzymatically reduced to tetrahydrofolate by the enzyme dihydrofolate reductase. This biochemical reaction is the target of a number of chemotherapeutic antimetabolites such as methotrexate that bind to the enzyme and prevent the reduction. Folic acid is found in brewer's yeast, liver, fruits, leafy vegetables, oranges, rice, soybeans, and wheat. Clinically, folic acid promotes normal red blood cell formation, helps to maintain the central nervous system, and promotes normal growth and development. Deficiencies in folic acid cause conditions such as anemia, weakness, lack of energy, paleness, mental confusion, and headaches.
Inositol (Myo-Inositol) – A useful sugar once thought to be a!vitamin.
Inositol is a simple carbohydrate that was originally thought to be essential to good health, but has since been demonstrated not be a vitamin. In the body, inositol is metabolized into phosphatidylinositol, which then acts as a second messenger system to stimulate the release of calcium from its intracellular storage site in the endoplasmic reticulum. The sugar has also been implicated in improving the transmission of neural signals in individuals afflicted with diabetic nerve damage and numbness. Major sources of inositol include beans, citrus fruit, nuts, rice, veal, pork, and wheat germ. There are no known deficiency symptoms in humans.
Menadione (Vitamin K) – A fat-soluble vitamin that helps to clot blood.
Menadione is a fat-soluble vitamin precursor that is converted into menaquinone in the liver. The primary known function of vitamin K is to assist in the normal clotting of blood, but it may also play a role in normal bone calcificaton. Vitamin K is primarily found in green leafy vegetables, but also in lesser amounts in some dairy products, meat, eggs, and fruits.
second image of Menadione (Vitamin K)
Niacin (Nicotinamide, Vitamin B-3) – A pyridine important in nucleic acid metabolism.
For metabolic purposes, niacin is interchangeable with its amide, niacinamide, also known as nicotinamide. Important in the biochemistry of humans and other organisms, both substances are components of the coenzymes nicotinamide adenine dinucleotide (NAD) and nicotinamide adenine dinucleotide phosphate (NADP), which function in a number of oxidation and reduction reactions catalyzed by enzymes. A niacin deficiency in humans often leads to a chronic illness called pellagra, characterized by gastrointestinal problems, lesions of the skin, and dementia. In dogs, a similar condition is known as black tongue disease. Both illnesses can generally be avoided by regularly including sources of niacin in the diet, including legumes, lean meats, and whole-grain or enriched breads and cereals. Some protein-rich food items that are poor sources of niacin, such as eggs and milk, can also help reduce the risk of niacin deficiency because they contain tryptophan, an amino acid that can be converted into niacin through bacterial action in the body.
second image of Niacin (Nicotinamide, Vitamin B-3)
PABA (Para-aminobenzoic acid, Vitamin B-x) – Bacterial vitamin that serves as a sunscreen.
Para-aminobenzoic acid (PABA), a component of pteroylglutamate, was once considered a vitamin and named vitamin B-x because it serves as a provitamin for some bacteria. Later studies in humans demonstrated that it does not have vitamin activity because humans lack the ability to synthesize folate from PABA. This biochemical is very useful in other ways and has been extensively utilized as a sunscreen in topical lotions to protect the skin from harmful ultraviolet radiation upon exposure to the sun. It is also effective in the treatment of vitiligo, a condition that causes discoloration of the skin. Natural sources of PABA include bran, kidney, liver, molasses, wheat germ, and yogurt. There are no reported symptoms arising from a dietary deficiency of PABA.
Pangamic Acid (Vitamin B15) – The non-vitamin “vitamin” that cures everything.
There have been a number of false claims about the biological activity of pangamic acid, a derivative of the amino acid glycine (pangamic acid is dimethyl glycine). This substance has been reported to be an oxygenator of body tissues, and also as an excellent scavenger of free radicals. Unfortunately, none of these claims has held up under scientific scrutiny. Therefore, we suggest that visitors avoid using this chemical as a vitamin suppliment until further work has been conducted on the biological properties.
Pantothenic Acid (Pantothenate, Vitamin B-5) – Important for normal growth.
Pantothenic acid was discovered in 1933 by Dr. R. J. Williams and was found to be a true vitamin shortly thereafter. Its name is derived from the Greek word pantos that means "everywhere", which is appropriate for this widely distributed vitamin. Pantothenic acid is an integral part of coenzyme A and plays the important role of decarboxylating pyruvate in the citric acid cycle. Clinically, pantothenic acid is necessary for the synthesis of red blood cells, steroid metabolism, neuron activity, and stimulation of antibody production. Common sources of pantothenic acid are cheese, corn, eggs, liver, meats, peanuts, peas soybeans, brewer's yeast, and wheat germ. Because of its wide occurance, pantothenic acid deficiency is very rare unless specifically engineered for the purposes of biochemical investigations.
Pyridoxine (Pyridoxal phosphate, Vitamin B-6) – A very versatile coenzyme.
Pyridoxine was discovered in the 1930s as the result of a series of nutritional investigations of rats fed vitamin-free diets. The original compound that was isolated is pyridoxine, named due to its structural similarity with pyridine, but possessing an additional hydroxymethyl group in the para position. In the body, however, the parahydroxymethyl moiety is oxidized to an aldehyde and the similar group in the meta position is phosphorylated, resulting in the biologically active pyridoxal phosphate. This coenzyme is remarkably versatile, being involved in transaminations, decarboxylations, racemizations, and numerous modifications of amino acid side chains. Clinically, pyridoxine helps normal function of the brain, promotes blood cell formation, maintains the chemical balance among body fluids, and assists in carbohydrate, protein, and fat metabolism. Common sources of pyridoxine include bananas, carrots, nuts, rice, fish, soybeans, and wheat germ. Symptoms of pyridoxine deficiency are very non-specific and hard to reproduce.
second image of Pyridoxine (Vitamin B-6)
Retinol (Vitamin A) – The first vitamin to be discovered.
The first nutritional deficiency disease to be identified and studied was night blindness. Ancient cultures recognized this and utilized cooked liver as both a topical and systemic cure for this malady. Retinol was first identified in 1920 and, being the first vitamin, was named vitamin A under the alphabetical nomenclature system. Its high concentration in the liver is due to the fat-soluble nature of this polyene biochemical, although because of the storage mechanism, excessive doses of vitamin A can be very toxic. The most critical biochemical to vision is retinal, an aldehyde that can be synthesized in vivo from retinol by NAD oxidation. Retinal exists in several isomeric states that are modulated by photon irridation and are very important in the conversion of light waves into vision. The most common source of vitamin A is liver, but many plants contain beta-carotene, which is metabolically converted to vitamin A. Symptoms associated with a deficiency of vitamin A are night blindness, changes in the eyes, poor bone growth, weak tooth enamel, slow growth, and dry skin.
second image of Retinol (Vitamin A)
Riboflavin (Vitamin B-2) – The vitamin that gives urine its yellow color.
Riboflavin is a water-soluble vitamin that was named from the Latin word flavius (yellow) to denote the deep color of crystals formed from the pure vitamin and the deep yellow color it gives to urine. Biochemically, riboflavin is metabolized to form the flavin coenzymes: flavin adenine dinucleotide (FAD) and flavin mononucleotide (FMN). The functional moiety in both coenzymes is riboflavin's isoalloxazine ring system, which serves as a two-electron acceptor in enzymatic biochemical reductions. Enzymes that use a flavin cofactor are termed "flavoproteins" and have been extensively studied. Common sources of riboflavin are almonds, yeast, cheese, eggs, chicken, beef, kidney, liver, and wheat germ. Clinically, riboflavin promotes normal growth, helps with the breakdown of fat, and assists in the synthesis of steroids, red blood cells, and glycogen. Symptoms associated with riboflavin deficiency are inflammation of the tongue, light sensitivity, itching, dizziness, insomnia, and slow learning.
second image of Riboflavin (Vitamin B-2)
Thiamine (Vitamin B-1) – A sure cure for Beriberi.
The first recognized vitamin deficiency disease was beriberi, a condition that is manifested by numerous neurological and metabolic disorders. Sufficient thiamine in the diet is a sure cure for beriberi, a fact that was established over a long period of time through crude dietary experiments by the Chinese, Japanese, and Dutch. Biochemically, thiamine forms a coenzyme after phosphorylation by an ATP-dependent pyrophosphorylase. Thiamine pyrophosphate contains a substituted pyrimidine nitrogen heterocyclic ring and a thiazole nitrogen-sulfur heterocycle. The thiazole moiety is responsible for the coenzyme's activity in pyruvate metabolism where it acts to perform a nonoxidative decarboxylation. Clinically, thiamine helps to maintain normal function of the nervous system, muscles, and heart, and is necessary for normal growth and development. Common sources of thiamine are kidney, liver, brewer's yeast, flour, beans, pork, salmon, soybeans, and wheat germ. Symptoms of thiamine deficiency are loss of appetite, fatigue, nausea, vomiting, and mental problems. Severe deficiency leads to beriberi, pain in the arms and legs, heart enlargement and fluid accumulation.
Alpha-Tocopherol (vitamin E) – What some people call the “love” vitamin is really a free radical scavenger.
Vitamin E was the fifth vitamin discovered when researchers found that a dietary deficiency in laboratory rats produced fetal death in pregnant females. The name "tocopherol" was derived from the Greek words for childbirth (tos), to bring forth (phero), and the chemical designation for an alcohol (ol). Vitamin E acts as a co-enzyme in cellular membranes and serves as a scavenger for free radicals that are destructive to the membrane and internal cellular components. Natural sources of vitamin E are vegetable oils, sunflower seeds, almonds, and peanuts.
second image of alpha-Tocopherol (Vitamin E)