Macronutrients and Micronutrients: Vitamins and Minerals L. Scheffler 1 Micronutrients and Macronutrients Micronutrients are substances required in very small amounts (mg or μg) and that mainly function as co-factors of enzymes ( < 0.005% body weight). Examples include: 1. Vitamins 2. Trace minerals (Fe, Cu, F, Zn, I, Se, Mn, Mo, Cr, Co and B). Macronutrients are chemical substances that are required in relatively large amounts (> 0.005% body weight). Examples include proteins, fats, carbohydrates and minerals (Na, Mg, K, Ca, P, S, and Cl). 2 Micronutrients Vitamins and Minerals Vitamins and minerals are essential for the maintenance of good health and the prevention of a number of diseases. • Vitamins are generally organic molecules • Minerals are inorganic substances usually in ion form 3 Micronutrients Vitamins Vitamins are naturally occurring organic compounds that are essential to metabolic or other functions in the body. Most vitamins cannot be synthesized by the body. They must be supplied in the diet. Vitamins are usually classified as water soluble or fat soluble 4 Micronutrients Minerals Minerals are inorganic and are found in the soil and water absorbed by plants or eaten by animals. The human body requires substantial amounts of minerals on a daily basis to ensure proper functioning of the organs, bones, tissue and immune system. Minerals may be classified as macro-minerals or trace minerals 5 Minerals Macro-minerals Trace Minerals 6 Minerals Trace Minerals Macro-minerals 7 Minerals Mineral What the mineral does Food sources Sodium Fluid and electrolyte balance, supports muscle contraction and nerve impulse transmissions salt, soy sauce, bread, milk, meats Chloride Maintains fluid and electrolyte balance, aids in digestion salt, soy sauce, milk, eggs, meats Potassium Maintains fluid and electrolyte balance, cell integrity, muscle contractions and nerve impulse transmission potatoes, vegetables, banana, strawberries, cod, milk Calcium Formation of bones and teeth, supports blood clotting milk, yogurt, cheddar cheese, Swiss cheese, tofu, sardines, green beans, spinach, broccoli Phosphorus Formation of cells, bones and teeth, all animal foods (meats, fish, poultry, eggs, milk) Magnesium Supports bone mineralization, protein Green vegetables, tomato juice, beans, cashews, halibut maintains acid-base balance building, muscular contraction, nerve impulse transmission, immunity Iron Part of the protein hemoglobin (carries oxygen throughout body's cells) spinach, broccoli, green beans, tomato juice, beef liver 8 Minerals Mineral Function Food sources Zinc Enzymes production of genetic material/proteins, vitamin A transport, wound healing, sperm production and the normal development of the fetus Green vegetables, tomato juice ,lentils, oysters, shrimp, crab, meats yoghurt, cheese Selenium Antioxidant, works with vitamin E to protect body from oxidation seafood, meats and grains Iodine Thyroid hormones regulate growth, development and metabolic rate salt, seafood, bread, milk, cheese Copper Absorption/utilization of iron, formation of hemoglobin , enzymes meats, water Manganese Facilitates many cell processes widespread in foods Fluoride formation of bones and teeth, helps to make teeth resistant to decay fluoridated drinking water, tea, seafood Chromium Associated with insulin and is required for vegetable oils, liver, whole the release of energy from glucose grains, cheese, nuts Molybdenum Facilitates many cell processes legumes, organ meats 9 Vitamin Characteristics Each vitamin has one or more specific purposes. Vitamins are essential to life processes. Vitamins are generally used by the body with very minimal changes Vitamins are usually required in only small amounts Most vitamins cannot be synthesized by the body directly 10 Important Vitamins Vitamin Function Source Supports vision, skin, bone and tooth growth, immunity and reproduction mango, broccoli, butternut squash, carrots, tomato juice, sweet potatoes, pumpkin, beef liver Collagen synthesis, amino acid metabolism, helps iron absorption, antioxidant Fruits and vegetables D Promotes bone mineralization Self-synthesis milk, egg yolk, liver, fatty fish B12 New cell synthesis, Breaking down fatty acids / amino acids, nerve cell maintenance Meats, poultry, fish, shellfish, milk, eggs E Antioxidant, regulation of oxidation reactions, supports cell membrane stabilization Shrimp, cod, wheat germ, tofu, polyunsaturated vegetable oils, sweet potatoes, K Synthesis of blood-clotting proteins, regulates blood calcium Liver, leafy green vegetables, spinach, broccoli, cabbage, 11 A Retinol C Ascorbic Acid Classification of Vitamins Vitamins can be classified as either • Water soluble • Fat soluble. Water soluble vitamins are generally involved in the cellular metabolism of energy supplying nutrients. Fat soluble vitamins often have very specialized functions 12 Water Soluble Vitamins Water soluble vitamins usually contain hydrogen attached to electronegative atoms such as oxygen or nitrogen. They easily form hydrogen bonds with water molecules. Water soluble vitamins do not accumulate in the body, so regular supplies are necessary 13 Water Soluble Vitamins Examples of water soluble vitamins Vitamin C Vitamin B1 (Thiamine) 14 Fat Soluble Vitamins Fat soluble vitamins have long nonpolar hydrocarbon chains or rings. Common fat soluble vitamins include • A, • D, • E, •F • K. 15 Fat Soluble Vitamins Fat soluble vitamins usually accumulate in tissues and are not leached out quickly. Unlike water soluble vitamins, an excess of a fat soluble vitamin can be just as harmful as a deficiency 16 Examples of Fat Soluble Vitamins Vitamin D 17 Examples of Fat Soluble Vitamins Vitamin K 18 Vitamin C- Sources Vitamin C is found in many fresh fruits and vegetables. It contains several polar groups, making it very water soluble. Cooking vegetables in water tends to leach the vitamin from the food. Cooked foods also contain less vitamin C, since it is also easily oxidized and hence destroyed in the cooking process. 19 Vitamin Functions Involved in the biosynthesis of the protein, collagen, found in connective tissues such as cartilage, ligaments, and tendons Aid in healing wounds and helping to prevent bacterial infections. 20 Vitamin C Functions Massive doses of vitamin C have often been thought to help in the prevention of the common cold, There is NO reliable evidence to show that this is true 21 Vitamin C Deficiencies Scurvy or Scorbutus. Symptoms include 1. swollen legs, 2. rotting gums, 3. and bloody lesions. Common among sailors in the 18th and 19th centuries who spent a long time at sea without fresh fruits and vegetables 22 Vitamin A Vitamin A is also known as retinol The long chain hydrocarbon structure of vitamin A means that the vitamin is essentially non-polar. Hence it is fat soluble rather than water soluble. 23 Vitamin A Sources Commonly found in cod liver oil, green vegetables, and fruit. Carrots indirectly serve as a source of vitamin A since they contain b carotene which the body readily converts to vitamin A 24 Vitamin A Functions Vitamin A is fat soluble. It is not readily broken down by cooking. Role in aiding in night vision. 25 Vitamin A Functions Retinol is oxidized to retinal, which combines with the protein opsin to form rhodopsin. Rhodopsin is the active agent which converts light signals to electrical impulses that the optic nerve transmits to the brain Retinol Retinal 26 Vitamin A Deficiencies A deficiency in vitamin A results in night blindness. The most serious deficiency results in a condition known as Xeropthalmia, a severe form of conjunctivitius or blindness. 27 Vitamin D - Sources Vitamin D is commonly found in fish liver oil as well as egg yokes. Unlike other vitamins, the body synthesizes vitamin D in the skin through the action of ultraviolet light on 7-dehydrochlosterol Like vitamin A, the long chain Hydrocarbon structure makes vitamin D fat soluble 28 Vitamin D Functions Vitamin D is an important regulator of calcium metabolism. It is involved in the uptake of calcium and phosphate ions from food into the body. It is necessary for the proper formation of bone structures and teeth. 29 Vitamin D A serious deficiency in vitamin D results in a condition known as Ricketts. Ricketts is characterized by bone softening an malformation. Child with Ricketts and two years after treatment 30 Vitamin D Vitamin D is destroyed by bleaching agents that are often used in the manufacture of purified white flour 31 Micronutrient Deficiencies Vitamin Deficiency Diseases • Retinol (Vitamin A) xerophthalmia / night blindness • Ascorbic acid (Vitamin C) scurvy or scorbutus • Calciferol (Vitamin D) rickets. • Niacin (Vitamin B3) pellagra • Thiamin (Vitamin B1) beriberi Mineral Deficiency Diseases • Iron — anemia • Iodine — goiter 32 Macro-nutrient Deficiencies Macronutrient deficiencies diseases in chlidren often result from a lack of protein Kwashiorkor is a specific wasting away often occurring in infants at weaning. It results from a lack of protein in the diet Marasmus is a wasting away of the body tissues from the lack Kwashiorkor of calories as well as protein in the diet. The child is fretful rather than apathetic and is skinny rather than swollen with edema. Marasmus 33 Nutritional Deficiencies Proposed approaches to combating nutritional deficiencies world-wide include: • Providing food rations that are composed of fresh and vitamin- and mineral-rich foods. • Adding nutrients missing in commonly consumed foods. • Genetic modification of food. • Providing nutritional supplements. • Providing selenium supplements to people eating foods grown in selenium-poor soil. 34