Learning Objectives List reasons why vitamins and minerals are critical to a healthy diet. Describe the functional role, intake recommendations and sources of vitamins and major minerals. Learn about the importance and sources of dietary fiber. Learn about the importance of water. Vitamins and minerals are essential to human health and can be obtained in our diet from different types of food. Dietary Minerals Minerals in food are inorganic compounds that work with other nutrients to ensure the body functions properly. Minerals are abundant in our everyday lives. From the soil in your front yard to the jewelry you wear on your body, we interact with minerals constantly. There are 20 essential minerals that must be consumed in our diets to remain healthy. The amount of each mineral found in our bodies vary greatly and therefore, so does consumption of those minerals. When there is a deficiency in an essential mineral, health problems may arise. Major minerals (Figure \(\PageIndex{1}\)) are classified as minerals that are required in the diet each day in amounts larger than 100 milligrams. These include sodium, potassium, chloride, calcium, phosphorus, magnesium, and sulfur. These major minerals can be found in various foods. Consuming a varied diet significantly improves an individual’s ability to meet their nutrient needs. The most common minerals in the body are calcium and phosphorous, both of which are stored in the skeleton and necessary for the hardening of bones. Most minerals are ionized, and their ionic forms are used in physiological processes throughout the body. Sodium and chloride ions are electrolytes in the blood and extracellular tissues, and iron ions are critical to the formation of hemoglobin. There are additional trace minerals that are still important to the body’s functions, but their required quantities are much lower. Like vitamins, minerals can be consumed in toxic quantities (although it is rare). A healthy diet includes most of the minerals your body requires, so supplements and processed foods can add potentially toxic levels of minerals. Tables \(\PageIndex{1}\) and \(\PageIndex{2}\) provide a summary of minerals and their function in the body. Table \(\PageIndex{1}\) Major Minerals and their Function in the Body. Major Minerals Mineral Sources Recommended daily allowance Function Problems associated with deficiency Potassium Meats, some fish, fruits, vegetables, legumes, dairy products 4700 mg Nerve and muscle function; acts as an electrolyte Hypokalemia: weakness, fatigue, muscle cramping, gastrointestinal problems, cardiac problems Sodium Table salt, milk, beets, celery, processed foods 2300 mg Blood pressure, blood volume, muscle and nerve function Rare Calcium Dairy products, dark green leafy vegetables, blackstrap molasses, nuts, brewer’s yeast, some fish 1000 mg Bone structure and health; nerve and muscle functions, especially cardiac function Slow growth, weak and brittle bones Phosphorous Meat, milk 700 mg Bone formation, metabolism, ATP production Rare Magnesium Whole grains, nuts, leafy green vegetables 310–420 mg Enzyme activation, production of energy, regulation of other nutrients Agitation, anxiety, sleep problems, nausea and vomiting, abnormal heart rhythms, low blood pressure, muscular problems Chloride Most foods, salt, vegetables, especially seaweed, tomatoes, lettuce, celery, olives 2300 mg Balance of body fluids, digestion Loss of appetite, muscle cramps Table \(\PageIndex{2}\) Trace Minerals and their Function in the Body. Trace Minerals Mineral Sources Recommended daily allowance Function Problems associated with deficiency Iron Meat, poultry, fish, shellfish, legumes, nuts, seeds, whole grains, dark leafy green vegetables 8–18 mg Transport of oxygen in blood, production of ATP Anemia, weakness, fatigue Zinc Meat, fish, poultry, cheese, shellfish 8–11 mg Immunity, reproduction, growth, blood clotting, insulin and thyroid function Loss of appetite, poor growth, weight loss, skin problems, hair loss, vision problems, lack of taste or smell Copper Seafood, organ meats, nuts, legumes, chocolate, enriched breads and cereals, some fruits and vegetables 900 µg Red blood cell production, nerve and immune system function, collagen formation, acts as an antioxidant Anemia, low body temperature, bone fractures, low white blood cell concentration, irregular heartbeat, thyroid problems Iodine Fish, shellfish, garlic, lima beans, sesame seeds, soybeans, dark leafy green vegetables 150 µg Thyroid function Hypothyroidism: fatigue, weight gain, dry skin, temperature sensitivity Sulfur Eggs, meat, poultry, fish, legumes NaN Component of amino acids Protein deficiency Fluoride Fluoridated water 3–4 mg Maintenance of bone and tooth structure Increased cavities, weak bones and teeth Manganese Nuts, seeds, whole grains, legumes 1.8–2.3 mg Formation of connective tissue and bones, blood clotting, sex hormone development, metabolism, brain and nerve function Infertility, bone malformation, weakness, seizures Cobalt Fish, nuts, leafy green vegetables, whole grains NaN Component of B12 NaN Selenium Brewer’s yeast, wheat germ, liver, butter, fish, shellfish, whole grains 55 µg Antioxidant, thyroid function, immune system function Muscle pain Chromium Whole grains, lean meats, cheese, black pepper, thyme, brewer’s yeast 25–35 µg Insulin function High blood sugar, triglyceride, and cholesterol levels Molybdenum Legumes, whole grains, nuts 45 µg Cofactor for enzymes Rare The Vitamins: Vital, but Not All are Amines In 1747, the Scottish surgeon James Lind discovered that citrus foods helped prevent scurvy, a particularly deadly disease in which collagen is not properly formed, causing poor wound healing, bleeding of the gums, severe pain, and death. In 1753, Lind published his Treatise on the Scurvy , which recommended using lemons and limes to avoid scurvy, which was adopted by the British Royal Navy. This led to the nickname limey for British sailors. In East Asia, where polished white rice was the common staple food of the middle class, beriberi resulting from lack of vitamin B 1 was endemic. In 1884, Takaki Kanehiro, a British-trained medical doctor of the Imperial Japanese Navy, observed that beriberi was endemic among low-ranking crew who often ate nothing but rice, but not among officers who consumed a Western-style diet. This convinced Takaki and the Japanese Navy that diet was the cause of beriberi, but they mistakenly believed that sufficient amounts of protein prevented it. That diseases could result from some dietary deficiencies was further investigated by Christiaan Eijkman, who in 1897 discovered that feeding unpolished rice instead of the polished variety to chickens helped to prevent beriberi in the chickens. The following year, Frederick Hopkins postulated that some foods contained "accessory factors" — in addition to proteins, carbohydrates, fats etc. — that are necessary for the functions of the human body. Hopkins and Eijkman were awarded the Nobel Prize for Physiology or Medicine in 1929 for their discoveries. In 1910, the first vitamin complex was isolated by Japanese scientist Umetaro Suzuki, who succeeded in extracting a water-soluble complex of micronutrients from rice bran and named it aberic acid (later Orizanin ). He published this discovery in a Japanese scientific journal. When the article was translated into German, the translation failed to state that it was a newly discovered nutrient, a claim made in the original Japanese article, and hence his discovery failed to gain publicity.In 1912 Polish-born biochemist Casimir Funk, working in London, isolated the same complex of micronutrients and proposed the complex be named "vitamine". It was later to be known as vitamin B 3 (niacin), though he described it as "anti-beri-beri-factor" (which would today be called thiamine or vitamin B 1 ). Funk proposed the hypothesis that other diseases, such as rickets, pellagra, coeliac disease, and scurvy could also be cured by vitamins. Vitamine to Vitamin Max Nierenstein a friend and reader of Biochemistry at Bristol University reportedly suggested the "vitamine" name (from "vital amine"). The name soon became synonymous with Hopkins' "accessory factors", and, by the time it was shown that not all vitamins are amines, the word was already ubiquitous. In 1920, Jack Cecil Drummond proposed that the final "e" be dropped to deemphasize the "amine" reference, after researchers began to suspect that not all "vitamines" (in particular, vitamin A) have an amine component. Vitamins are organic compounds found in foods and are a necessary part of the biochemical reactions in the body. They are involved in a number of processes, including mineral and bone metabolism, and cell and tissue growth, and they act as cofactors for energy metabolism. The B vitamins play the largest role of any vitamins in metabolism (Tables \(\PageIndex{3}\) and \(\PageIndex{4}\)) You get most of your vitamins through your diet, although some can be formed from the precursors absorbed during digestion. For example, the body synthesizes vitamin A from the β-carotene in orange vegetables like carrots and sweet potatoes. Vitamins are either fat-soluble or water-soluble. Fat-soluble vitamins A, D, E, and K, are absorbed through the intestinal tract with lipids in chylomicrons. Vitamin D is also synthesized in the skin through exposure to sunlight. Because they are carried in lipids, fat-soluble vitamins can accumulate in the lipids stored in the body. If excess vitamins are retained in the lipid stores in the body, hypervitaminosis can result. Water-soluble vitamins, including the eight B vitamins and vitamin C, are absorbed with water in the gastrointestinal tract. These vitamins move easily through bodily fluids, which are water based, so they are not stored in the body. Excess water-soluble vitamins are excreted in the urine. Therefore, hypervitaminosis of water-soluble vitamins rarely occurs, except with an excess of vitamin supplements. Fat Soluble Vitamins From the structures shown below, it should be clear that these compounds have more than a solubility connection with lipids. VitaminsA is a terpene, and vitamins E and K have long terpene chains attached to an aromatic moiety. The structure of vitamin D can be described as a steroid in which ring B is cut open and the remaining three rings remain unchanged. The precursors of vitamins A and D have been identified as the tetraterpene beta-carotene and the steroid ergosterol, respectively. Table \(\PageIndex{3}\) lists the different fat soluble vitamins and its function. Table \(\PageIndex{3}\) Fat Soluble Vitamins and Their Function. Vitamin and alternative name Sources Recommended daily allowance Function Problems associated with deficiency A retinal or β-carotene Yellow and orange fruits and vegetables, dark green leafy vegetables, eggs, milk, liver 700–900 µg Eye and bone development, immune function Night blindness, epithelial changes, immune system deficiency D cholecalciferol Dairy products, egg yolks; also synthesized in the skin from exposure to sunlight 5–15 µg Aids in calcium absorption, promoting bone growth Rickets, bone pain, muscle weakness, increased risk of death from cardiovascular disease, cognitive impairment, asthma in children, cancer E tocopherols Seeds, nuts, vegetable oils, avocados, wheat germ 15 mg Antioxidant Anemia K phylloquinone Dark green leafy vegetables, broccoli, Brussels sprouts, cabbage 90–120 µg Blood clotting, bone health Hemorrhagic disease of newborn in infants; uncommon in adults Web link More detailed information on the different fat soluble vitamins can be found on the link below. https://med.libretexts.org/Bookshelves/Nutrition/Book%3A_Human_Nutrition_(University_of_Hawaii)/9%3A_Vitamins/9.2%3A_Fat-Soluble_Vitamins Water Soluble Vitamins All water-soluble vitamins (Table \(\PageIndex{4}\)) play a different kind of role in energy metabolism; they are required as functional parts of enzymes involved in energy release and storage. Vitamins and minerals that make up part of enzymes are referred to as coenzymes and cofactors , respectively. Coenzymes and cofactors are required by enzymes to catalyze a specific reaction. They assist in converting a substrate to an end-product. Coenzymes and cofactors are essential in catabolic pathways and play a role in many anabolic pathways too. In addition to being essential for metabolism, many vitamins and minerals are required for blood renewal and function. At insufficient levels in the diet these vitamins and minerals impair the health of blood and consequently the delivery of nutrients in and wastes out, amongst its many other functions. Table \(\PageIndex{4}\) Water Soluble Vitamins and Their Function. Vitamin and alternative name Sources Recommended daily allowance Function Problems associated with deficiency B1 thiamine Whole grains, enriched bread and cereals, milk, meat 1.1–1.2 mg Carbohydrate metabolism Beriberi, Wernicke-Korsikoff syndrome B2 riboflavin Brewer’s yeast, almonds, milk, organ meats, legumes, enriched breads and cereals, broccoli, asparagus 1.1–1.3 mg Synthesis of FAD for metabolism, production of red blood cells Fatigue, slowed growth, digestive problems, light sensitivity, epithelial problems like cracks in the corners of the mouth B3 niacin Meat, fish, poultry, enriched breads and cereals, peanuts 14–16 mg Synthesis of NAD, nerve function, cholesterol production Cracked, scaly skin; dementia; diarrhea; also known as pellagra B5 pantothenic acid Meat, poultry, potatoes, oats, enriched breads and cereals, tomatoes 5 mg Synthesis of coenzyme A in fatty acid metabolism Rare: symptoms may include fatigue, insomnia, depression, irritability B6 pyridoxine Potatoes, bananas, beans, seeds, nuts, meat, poultry, fish, eggs, dark green leafy vegetables, soy, organ meats 1.3–1.5 mg Sodium and potassium balance, red blood cell synthesis, protein metabolism Confusion, irritability, depression, mouth and tongue sores B7 biotin Liver, fruits, meats 30 µg Cell growth, metabolism of fatty acids, production of blood cells Rare in developed countries; symptoms include dermatitis, hair loss, loss of muscular coordination B9 folic acid Liver, legumes, dark green leafy vegetables, enriched breads and cereals, citrus fruits 400 µg DNA/protein synthesis Poor growth, gingivitis, appetite loss, shortness of breath, gastrointestinal problems, mental deficits B12 cyanocobalamin Fish, meat, poultry, dairy products, eggs 2.4 µg Fatty acid oxidation, nerve cell function, red blood cell production Pernicious anemia, leading to nerve cell damage C ascorbic acid Citrus fruits, red berries, peppers, tomatoes, broccoli, dark green leafy vegetables 75–90 mg Necessary to produce collagen for formation of connective tissue and teeth, and for wound healing Dry hair, gingivitis, bleeding gums, dry and scaly skin, slow wound healing, easy bruising, compromised immunity; can lead to scurvy Web link More detailed information on the different water soluble vitamins can be found on the link below. https://med.libretexts.org/Bookshelves/Nutrition/Book%3A_Human_Nutrition_(University_of_Hawaii)/9%3A_Vitamins/9.3%3A_Water-Soluble_Vitamins Vitamins as Antioxidants The “big three” vitamin antioxidants are vitamins E, A, and C, although it may be that they are called the “big three” only because they are the most studied. Other antioxidants obtained from the diet are given in Table \(\PageIndex{5}\). A simplified diagram on the role of antioxidants is shown in Figure \(\PageIndex{4}\). Table \(\PageIndex{5}\) Some Antioxidants Obtained from Diet and Their Related Functions. 0 1 Antioxidant Functions Attributed to Antioxidant Capacity Vitamin A Protects cellular membranes, prevents glutathione depletion, maintains free radical detoxifying enzyme systems, reduces inflammation Vitamin E Protects cellular membranes, prevents glutathione depletion Vitamin C Protects DNA, RNA, proteins, and lipids, aids in regenerating vitamin E Carotenoids Free radical scavengers Lipoic acid Free radical scavenger, aids in regeneration of vitamins C and E Phenolic acids Free radical scavengers, protect cellular membranes Effects of Cooking The USDA has conducted extensive studies on the percentage losses of various nutrients from different food types and cooking methods. Some vitamins may become more "bio-available" – that is, usable by the body – when foods are cooked. Table \(\PageIndex{6}\) below shows whether various vitamins are susceptible to loss from heat—such as heat from boiling, steaming, frying, etc. The effect of cutting vegetables can be seen from exposure to air and light. Water-soluble vitamins such as B and C dissolve into the water when a vegetable is boiled, and are then lost when the water is discarded. Table \(\PageIndex{6}\) Vitamin Stability Upon Air, Light and Heat Exposure. Source: Wikipedia. Vitamin Soluble in Water Stable to Air Exposure Stable to Light Exposure Stable to Heat Exposure Vitamin A no partially partially relatively stable Vitamin C very unstable yes no no Vitamin D no no no no Vitamin E no yes yes no Vitamin K no no yes no Thiamine (B1) highly no ? > 100 °C Riboflavin (B2) slightly no in solution no Niacin (B3) yes no no no Pantothenic Acid (B5) quite stable no no yes Vitamin B6 yes ? yes ? Biotin (B7) somewhat ? ? no Folic Acid (B9) yes ? when dry at high temp Cobalamin (B12) yes ? yes no Dietary Fiber and Water Dietary fiber consists of non-starch polysaccharides and other plant components such as cellulose, resistant starch, resistant dextrins, inulin, lignins, chitins, pectins, beta-glucans, and oligosaccharides already mentioned in Section 17.1. Dietary fibers can act by changing the nature of the contents of the gastrointestinal tract and by changing how other nutrients and chemicals are absorbed. Some types of soluble fiber absorb water to become a gelatinous, viscous substance which may or may not be fermented by bacteria in the digestive tract. Some types of insoluble fiber have bulking action and are not fermented. Lignin, a major dietary insoluble fiber source, may alter the rate and metabolism of soluble fibers. Other types of insoluble fiber, notably resistant starch, are fermented to produce short-chain fatty acids, which are physiologically active and confer health benefits. Health benefit from dietary fiber and whole grains may include a decreased risk of death and lower rates of coronary heart disease, colon cancer, and type 2 diabetes. Food sources of dietary fiber (Table \(\PageIndex{7}\) ) have traditionally been divided according to whether they provide soluble or insoluble fiber. Plant foods contain both types of fiber in varying amounts, according to the plant's characteristics of viscosity and fermentability. Advantages of consuming fiber depend upon which type of fiber is consumed and which benefits may result in the gastrointestinal system. Bulking fibers – such as cellulose, hemicellulose and psyllium – absorb and hold water, promoting regularity. Viscous fibers – such as beta-glucan and psyllium – thicken the fecal mass. Fermentable fibers – such as resistant starch and inulin – feed the bacteria and microbiota of the large intestine, and are metabolized to yield short-chain fatty acids, which have diverse roles in gastrointestinal health. Table \(\PageIndex{7}\) Types and Sources of Dietary Fiber. 0 1 2 Nutrient Food additive Source/Comments Water-insoluble dietary fibers Water-insoluble dietary fibers Water-insoluble dietary fibers β-glucans (a few of which are water-soluble) β-glucans (a few of which are water-soluble) β-glucans (a few of which are water-soluble) Cellulose E 460 cereals, fruit, vegetables (in all plants in general) Chitin — in fungi, exoskeleton of insects and crustaceans Hemicellulose NaN cereals, bran, timber, legumes Hexoses — wheat, barley Pentose — rye, oat Lignin — stones of fruits, vegetables (filaments of the garden bean), cereals Xanthan gum E 415 production with Xanthomonas-bacteria from sugar substrates Resistant starch NaN Can be starch protected by seed or shell (type RS1), granular starch (type RS2) or retrograded starch (type RS3) Resistant starch — high amylose corn, barley, high amylose wheat, legumes, raw bananas, cooked and cooled pasta and potatoes Water-soluble dietary fibers Water-soluble dietary fibers Water-soluble dietary fibers Arabinoxylan (a hemicellulose) — psyllium Fructans NaN replace or complement in some plant taxa the starch as storage carbohydrate Inulin — in diverse plants, e.g. topinambour, chicory, etc. Polyuronide Polyuronide Polyuronide Pectin E 440 in the fruit skin (mainly apples, quinces), vegetables Alginic acids(Alginates) E 400–E 407 in Algae Sodium alginate E 401 NaN Potassium alginate E 402 NaN Ammonium alginate E 403 NaN Calcium alginate E 404 NaN Propylene glycol alginate (PGA) E 405 NaN agar E 406 NaN carrageen E 407 red algae Raffinose — legumes Xylose — monosacharide, pentose Polydextrose E 1200 synthetic polymer, ca. 1kcal/g Lactulose — synthetic disaccharide Fiber Contents in Food Dietary fibers are found in fruits, vegetables and whole grains. The amount of fiber contained in common foods are in Table \(\PageIndex{8}\). Table \(\PageIndex{8}\) Amount of Fiber in Common Foods. Source Wikipedia Food group Serving mean Fibermass per serving Fruit 120 mL (0.5 cup) 1.1 g Dark green vegetables 120 mL (0.5 cup) 6.4 g Orange vegetables 120 mL (0.5 cup) 2.1 g Cooked dry beans (legumes) 120 mL (0.5 cup) 8.0 g Starchy vegetables 120 mL (0.5 cup) 1.7 g Other vegetables 120 mL (0.5 cup) 1.1 g Whole grains 28 g (1 oz) 2.4 g Meat 28 g (1 oz) 0.1 g The breakdown of total dietary fiber in terms of the amounts of soluble and insoluble fiber found in five different foods are listed in Table \(\PageIndex{9}\). Food Total Dietary Fiber Total Insoluble (Nonfermentable) Total Soluble (Fermentable) Cereal, all bran 30.1 28.0 2.1 Blueberries, fresh 2.7 2.4 0.3 Broccoli, fresh, cooked 3.5 3.1 0.4 Pork and beans, canned 4.4 3.0 1.4 Almonds, with skin 8.8 8.6 0.2 tr = trace amounts Dietary fiber is found in plants, typically eaten whole, raw or cooked, although fiber can be added to make dietary supplements and fiber-rich processed foods. Grain bran products have the highest fiber contents, such as crude corn bran (79 g per 100 g) and crude wheat bran (43 g per 100 g), which are ingredients for manufactured foods. Medical authorities, such as the Mayo Clinic, recommend adding fiber-rich products to the Standard American Diet (SAD) which is rich in processed and artificially sweetened foods, with minimal intake of vegetables and legumes. Plant Sources of Fiber Some plants contain significant amounts of soluble and insoluble fiber. For example, plums and prunes have a thick skin covering a juicy pulp. The skin is a source of insoluble fiber, whereas soluble fiber is in the pulp. Grapes also contain a fair amount of fiber. A listing of other plant sources of fiber is given in the table below. Table \(\PageIndex{10}\) Plant Sources of Soluble and Insoluble Fiber. 0 1 Sources of Soluble Fiber Sources of Insoluble Fiber legumes (peas, soybeans, lupins and other beans) oats, rye, chia, and barley some fruits (including figs, avocados, plums, prunes, berries, ripe bananas, and the skin of apples, quinces and pears) certain vegetables such as broccoli, carrots, and Jerusalem artichokes root tubers and root vegetables such as sweet potatoes and onions (skins of these are sources of insoluble fiber also) psyllium seed husks (a mucilage soluble fiber) and flax seeds nuts, with almonds being the highest in dietary fiber whole grain foods wheat and corn bran legumes such as beans and peas nuts and seeds potato skins lignans vegetables such as green beans, cauliflower, zucchini (courgette), celery, and nopal some fruits including avocado, and unripe bananas the skins of some fruits, including kiwifruit, grapes and tomatoes Fiber Supplements These are a few example forms of fiber that have been sold as supplements or food additives. These may be marketed to consumers for nutritional purposes, treatment of various gastrointestinal disorders, and for such possible health benefits as lowering cholesterol levels, reducing risk of colon cancer, and losing weight. Soluble fiber supplements may be beneficial for alleviating symptoms of irritable bowel syndrome, such as diarrhea or constipation and abdominal discomfort. Prebiotic soluble fiber products, like those containing inulin or oligosaccharides, may contribute to relief from inflammatory bowel disease, as in Crohn's disease, ulcerative colitis, and Clostridium difficile , due in part to the short-chain fatty acids produced with subsequent anti-inflammatory actions upon the bowel.Fiber supplements may be effective in an overall dietary plan for managing irritable bowel syndrome by modification of food choices. One insoluble fiber, resistant starch from high-amylose corn, has been used as a supplement and may contribute to improving insulin sensitivity and glycemic management as well as promoting regularity and possibly relief of diarrhea. One preliminary finding indicates that resistant corn starch may reduce symptoms of ulcerative colitis. Inulin Chemically defined as oligosaccharides occurring naturally in most plants, inulins have nutritional value as carbohydrates, or more specifically as fructans, a polymer of the natural plant sugar, fructose. Inulin is typically extracted by manufacturers from enriched plant sources such as chicory roots or Jerusalem artichokes for use in prepared foods. Subtly sweet, it can be used to replace sugar, fat, and flour, is often used to improve the flow and mixing qualities of powdered nutritional supplements, and has significant potential health value as a prebiotic fermentable fiber. Inulin is advantageous because it contains 25–30% the food energy of sugar or other carbohydrates and 10–15% the food energy of fat. As a prebiotic fermentable fiber, its metabolism by gut flora yields short-chain fatty acids (see below) which increase absorption of calcium, magnesium, and iron, resulting from upregulation of mineral-transporting genes and their membrane transport proteins within the colon wall. Among other potential beneficial effects noted above, inulin promotes an increase in the mass and health of intestinal Lactobacillus and Bifidobacterium populations. Inulin's primary disadvantage is its tolerance. As a soluble fermentable fiber, it is quickly and easily fermented within the intestinal tract, which may cause gas and digestive distress at doses higher than 15 grams/day in most people. Individuals with digestive diseases have benefited from removing fructose and inulin from their diet. While clinical studies have shown changes in the microbiota at lower levels of inulin intake, some of the health effects require higher than 15 grams per day to achieve the benefits. Vegetable Gums Vegetable gum fiber supplements are relatively new to the market. Often sold as a powder, vegetable gum fibers dissolve easily with no aftertaste. In preliminary clinical trials, they have proven effective for the treatment of irritable bowel syndrome. Examples of vegetable gum fibers are guar gum and gum arabic. Water Add all the ways you use water every day and you still will not come close to the countless uses water has in the human body. Of all the nutrients, water is the most critical as its absence proves lethal within a few days. Organisms have adapted numerous mechanisms for water conservation. Water uses in the human body can be loosely categorized into four basic functions: transportation vehicle, medium for chemical reactions, lubricant/shock absorber, and temperature regulator. On a typical day, the average adult will take in about 2500 mL (almost 3 quarts) of aqueous fluids. Although most of the intake comes through the digestive tract, about 230 mL (8 ounces) per day is generated metabolically, in the last steps of aerobic respiration. Additionally, each day about the same volume (2500 mL) of water leaves the body by different routes; most of this lost water is removed as urine. The kidneys also can adjust blood volume though mechanisms that draw water out of the filtrate and urine. The kidneys can regulate water levels in the body; they conserve water if you are dehydrated, and they can make urine more dilute to expel excess water if necessary. Water is lost through the skin through evaporation from the skin surface without overt sweating and from air expelled from the lungs. This type of water loss is called insensible water loss because a person is usually unaware of it. Summary Vitamins and minerals are essential parts of the diet. They are needed for the proper function of metabolic pathways in the body. Vitamins are not stored in the body, so they must be obtained from the diet or synthesized from precursors available in the diet. Minerals are also obtained from the diet, but they are also stored, primarily in skeletal tissues. Dietary fibers can act by changing the nature of the contents of the gastrointestinal tract and by changing how other nutrients and chemicals are absorbed. Whole grain, legumes, vegetables, and fruits are excellent sources of dietary fiber. Health benefit from dietary fiber and whole grains may include a decreased risk of death and lower rates of coronary heart disease, colon cancer, and type 2 diabetes. Contributors Template:ContribOpenStaxAP Template:ContribUofHawaiiNutrition Wikipedia Marisa Alviar-Agnew ( Sacramento City College )