Micronutrients:Vitamins and Minerals

Defining Micronutrient Needs• Estimated Average Requirement (EAR)

• Recommended Dietary Allowance (RDA)

• Adequate Intake (AI)

–Assumed nutritional goal when no RDA exists

• Tolerable Upper Intake (UL)

–Highest average daily nutrient intake level likely to pose no risk of adverse health effects to almost all individuals in the specified gender and life stage group

Definition of Vitamins• Vital, organic, dietary substance not manufactured

by the body in sufficient quantities to sustain life, so it must be supplied by diet.

• Not a macronutrient

• Non-caloric

• Necessary in small amounts

–Specific metabolic functions

–Prevent deficiency diseases

• Manufactured by plants during photosynthesis

• No particular chemical structure in common

Functions of Vitamins• Coenzymes

–Molecules that work with an enzyme to enable the enzyme to perform its function in the body; necessary in the utilization of vitamins and minerals

– B vitamins are part of coenzymes

– Coenzymes needed to perform certain functions, such as:

• Glucose metabolism

• Protein metabolism

• Fatty acid metabolism

–Without coenzymes energy production (ATP) is impossible leading to death

Functions of Vitamins• Tissue Structure and Protection–Vitamin C is involved in the synthesis of

collagen• Prevention of Deficiency Diseases–Scurvy: Bleeding in joints and other tissues by a

deficiency of Vitamin C–Beriberi: Nervous system disease caused by a

deficiency of Vitamin B1 (Thiamin)–Pellagra: Deficiency of Vitamin B3 (Niacin)

which can lead to dermatitis, dementia, and death

Classification of Vitamins• Fat-Soluble

–A

–D

–E

–K

• Water-Soluble– C

– B-Complex:

• B1 Thiamin

• B2 Riboflavin

• B3 Niacin

(Nicotinic acid)

• B5 Pantothenic Acid

• B6 Pyridoxine

• B7 Biotin

• B9 Folic Acid

• B12 Cobalamin

Vitamin Metabolism• The way in which our bodies digest,

absorb, and transport vitamins depends on Solubility

–Solubility: Ability of a substance to dissolve in a liquid

–Water-Soluble Vitamins

–Fat-Soluble Vitamins

Water-Soluble Vitamins• Easily absorbed and transported by blood

circulation

• Not stored, so must be eaten on regular basis

–Exceptions: B12 and B6

• Kidneys and Liver clear it

• Excess intake voided in urine

• Marginal deficiencies can develop within 4 weeks of inadequate intake

Vitamin C (Ascorbic Acid)• Functions:– Collagen synthesis for building and maintaining

connective tissue – Helps the body absorb iron for hemoglobin production• Hemoglobin is an iron containing protein in red

blood cells that carries oxygen to the tissues of the body

– Antioxidant, protecting the body from free radical damage• Free radicals are unstable and highly reactive

molecules which can damage cells and are linked to cancer, cardiovascular disease, and age-related diseases

Vitamin C (Ascorbic Acid) • Deficiency Disease: Scurvy• Deficiency Causes:– Tissue bleeding (easy

bruising)– Bone and joint bleeding– Susceptibility to bone fracture– Poor wound healing– Soft bleeding gums with

loosened teeth– Nosebleeds– Anemia– Decreased ability to fight

infection

Vitamin C Food Sources

• Cauliflower• Broccoli• Kiwi• Red and Green

Peppers• Hot peppers• Cantaloupe• Brussel Sprouts• Kale • Tomatoes• Papaya

• Mango• Sweet and White

potatoes• Strawberries• Citrus Fruits (lemons,

limes, oranges, grapefruits, tangerines)

• Watermelon, cherries, pears, cranberries, blueberries

• Spinach

Vitamin C Cooking, Storage, and Processing• Highly sensitive to air, light, and heat• Lost from foods during preparation (chopping), cooking,

baking (baking soda destroys Vitamin C), and storage • To retain vitamin C:– Eat fruits and vegetables raw – Steam, boil, or simmer foods in a minimal amount of

water, or microwave them for the shortest time possible– Cook potatoes in their skins– Refrigerate prepared juices, and store them for no more

than 2 to 3 days– Store cut raw fruits and vegetables in an airtight

container and refrigerate - do not soak or store in water. Vitamin C will be dissolved in the water

Vitamin C Requirements• 75mg/day for females

• 90mg/day for males

•Add 35mg/day for smokers–Smoking increases free radical production

Thiamin (B1) Functions

Gastrointestinal SystemCardiovascular System

Nervous System

Thiamin (B1)• Gastrointestinal System–Energy for cells and secretory glands

–Deficiency Causes:• Poor appetite

• Indigestion

• Constipation

• Poor stomach action

•Deficient hydrochloric

acid secretion

Thiamin (B1)• Nervous System–Energy for Central Nervous System (CNS)–Deficiency Causes:• Alertness and reflex responses decrease•Apathy• Fatigue• Irritability•Nerve irritation• Pain• Extreme cases Paralysis

Thiamin (B1)

• Cardiovascular System–Deficiency Causes:

•Weakening of heart

•Heart failure

•Blood circulation

problems

•Fluid accumulation

in lower part of legs

Thiamin (B1) Food Sources

Wheat germ, lean pork, beef, liver, eggs, fish,

whole or enriched grains, legumes, milk

Thiamin (B1) • Deficiency Disease: Beriberi (associated with

alcoholics)

• Symptoms of Beriberi include:

–Difficulty walking, loss of sensation in hands and feet, loss of muscle function or paralysis of the lower legs, mental confusion/speech difficulties, strange eye movements (nystagmus), edema in lower legs

• Stability:

–Destroyed by high cooking temperatures and water

• Requirements:

– 1.1 mg/day for females

– 1.2 mg/day for males

Riboflavin (B2)• Its name comes from its color (yellow-

green) and its component sugar, ribose

• Functions: –It is essential for the metabolism of

carbohydrates, amino acids, and lipids and also supports antioxidant protective function

–It helps prevent and is used to treat migraine headaches, cataracts, rheumatoid arthritis, acne, dermatitis, and eczema

Riboflavin (B2)• Deficiency Causes:– Cracked lips and mouth corners; a swollen, red tongue;

eyes burning, itching, or tearing from extra blood vessels in the cornea; and a scaly, greasy dermatitis in skin folds.

Riboflavin (B2)• The most important food source is Milk

• Other food sources: beef, liver, poultry, fish, mushrooms, spinach, and avocados

Riboflavin (B2)• Stability:–Destroyed by light; that is why milk is sold in

plastic or cardboard instead of glass

• Requirements: 1.1 to 1.3 mg/day for adults 18 years and older

Niacin (B3)• Functions: – Niacin partners with riboflavin and thiamin for energy

production (ATP)

– DNA repair

Niacin (B3)• Deficiency Disease:

–Pellagra which is characterized by dermatitis, diarrhea, dementia, and death

• Deficiency Causes:

–Weakness, poor appetite, and indigestion

Niacin (B3)• Food Sources:–Meat, poultry, fish, enriched grain products, peanuts,

dried beans, and peas• Stability:–Destroyed when cooking with water

• Requirements:– 14mg/day for women– 16 mg/day for men

• Toxicity:– Excessive Niacin can produce headaches, cramps,

liver problems, heartburn, and redness of the skin, face, and arms

Vitamin B6 (Pyridoxine)• Functions:– Protein metabolism– Neurotransmitter synthesis– One of the water-soluble vitamins that is stored in

tissues, particularly muscle tissue• Deficiency Causes:– Abnormal CNS function

• Food Sources:– Grains, enriched cereals, liver, kidney, pork, poultry,

garbanzo beans, bananas, baked potato• Requirements: 1.3 mg/day men and women up to 50 years

of age– Older Adults: 1.5mg/day for women and 1.7 mg/day for

men

Folate (B9)• Functions:

–Most stable form of folate is Folic Acid which is rarely found in foods but is in vitamin supplements and fortified food products

– Formation of DNA

– Participates in reproduction of every cell

– Active in cell renewal

– Grows cells rapidly (GI tract, blood, fetal tissue)

Folic Acid (B9)• Deficiency Disease:–Neural Tube Defects• Spina Bifida–Lower end of neural tube fails to close; spinal

cord and backbones do not develop properly–Severity depends on size & location of opening

in spine• Anencephaly–Upper end of neural tube fails to close; brain

fails to develop or is absent entirely–Pregnancies often end in miscarriages or death

soon after delivery

Folic Acid (B9)• Food Sources Include:

– Liver, dark green leafy veggies, legumes (pinto, black, kidney beans), soybeans, wheat germ, orange juice, asparagus, broccoli

Folic Acid (B9)• Requirements:–Males age 14 and older: 400 mcg/day

–Females age 14 - 50: 400 mcg/day plus 400 mcg/day from supplements or fortified foods

–Pregnant Women: 600 mcg/day

–Females age 50 and over: 400 mcg/day

• Stability:–Destroyed by heat, water, storage, and preparation

(chopping)

Cobalamin (B12)• Functions: –Synthesized from

bacteria in GI tract

–Essential for red blood cell formation and synthesis of non-protein portion of hemoglobin

–CNS functioning

Cobalamin (B12)• Deficiency Disease:– Pernicious Anemia: The red blood cells are abnormally

formed, due to an inability to absorb vitamin B12

• Food Sources:– Beef, chicken, liver, clams, oysters, crab, herring, milk,

Fat-Soluble Vitamins• Best absorbed when eaten with fat–Vitamin A is best absorbed with whole or

2% milk than from skim milk that contains no fat

• Stored for longer periods because they are deposited in adipose tissue and the liver

• Should not be consumed in excess without medical supervision

Vitamin A (Retinol)• Functions:

–Vision

–Health of Epithelial Tissue

• Skin and lining of organs

–Normal Bone Growth

• Osteoblasts and Osteoclasts

–Reproduction

• Sperm production

Vitamin A (Retinol)• It is part of rhodopsin, which is a substance that

enables the eye to adjust to different amounts of available light. Fluctuations in retinol levels can cause deficiencies with sight.

• Deficiency Diseases:– Xerosis: Inflamed eye lids– Xerophalmia: Blindness

• Deficiency Causes:– Night blindness– Slow adaptation to darkness– Glare blindness– Scaly skin

Vitamin A (Retinol)• Occurs in Two Forms:– Preformed or Retinol found in animals– Beta-carotene found in yellow, orange, and deep green

fruits and vegetables• Food Sources:– Fish liver oils, liver, egg yolk, butter, cream, kale, turnip

greens, spinach, carrots, sweet potatoes, yams, apricots

Vitamin A (Retinol)• Requirements:– 700 mcg/day for women– 900 mcg/day for men

• Toxicity Causes:– Hypervitaminosis: Excessive Vitamin A intake

– Headaches, blurry vision, joint pain, thickness of long bones, jaundice, liver damage (the liver stores large amounts)

• Stability:– Unstable when exposed to heat and oxygen– Cooking vegetables in an uncovered pot destroys much

of their vitamin content–Wilted vegetables destroys Vitamin A

Vitamin D (Cholecalciferol)• Not a true vitamin because it is made in the

body with the help of the sun’s ultraviolet rays• Group of steroid molecules

• Generated in skin of animals when light energy is absorbed

• Functions: –Absorption of Calcium and Phosphorous–Bone Mineralization

Vitamin D (Cholecalciferol)• Deficiency Disease:–Rickets: A condition

in growing children characterized by malformation of bones

–Osteomalacia: Softening of bones

• Food Sources:–Yeast, fatty fish,

fortified foods (milk)• Requirements:–Not established

• Toxicity Causes:– Decreased kidney

function

Vitamin E (Tocopherol)• Functions:–Antioxidant: Prevents oxidation of

cell structures by free radicals

–Protects red blood cells

Vitamin E (Tocopherol)• Deficiency Diseases:–Hemolytic Anemia: Red blood cells are destroyed in infants

• Deficiency Causes:–Disruption of synthesis of

myelin sheath in axon in adults and children. Muscles and vision are affected.

Vitamin E (Tocopherol)• Food Sources:– Best sources are vegetable oils (e.g., soybean, safflower)

– Other sources: nuts, milk, eggs, avocado, fish, cereal, leafy vegetables

• Requirements:– 15 mg/day for men

and women 14

years and older

• Stability:– Unstable to heat

Vitamin K (Phylloquinone)• Functions:– Blood clotting

– Bone development

• Deficiency Disease:– Not found in people

due to Vitamin K injection

given at birth

• Food Sources:– Spinach, broccoli, cabbage

Requirements:

– None

Antioxidant Role of Vitamins• Antioxidant–Chemical substance that

helps protect against cell damage from free radicals

• Free Radical–Unstable molecule;

missing an electron which makes it highly reactive and able to damage other molecules

Antioxidant Role of Vitamins• Free radicals increase potential for cellular

damage–Aging–Cancer–Diabetes–CAD–Exercise-Related Damage–CNS & Immune Functions

• Antioxidant Vitamins A, C, and E –Reduce potential for free radical damage–May protect against heart disease and cancer

Phytochemicals• Nonnutritive, natural

chemical compounds found in plant material

• Produced by sun exposure with plant

• Found in whole unrefined foods such as vegetables, fruits, legumes, nuts, seeds

• Found to inactivate cancer causing substances, stimulate

the immune system, protect against heart disease, help prevent cataracts

Lycopene• A carotenoid in the same family as beta-

carotene• It gives tomatoes, pink grapefruits,

watermelons, and apricots their red color• Phytochemical• Antioxidant• May protect against breast, prostate, lung,

bladder, cervix, and skin cancer• May reduce LDL’s and lower cholesterol

levels

Lycopene • Research shows that lycopene can be absorbed more

efficiently by the body after it has been processed into juice, sauce, paste, or ketchup

• Because lycopene is fat-soluble (as are vitamins, A, D, and E), absorption into tissues is improved when oil is added to the diet

• Food Sources: Tomatoes, pink grapefruit, tomato juice, tomato paste, ketchup, pizza and spaghetti sauce, guava, watermelon, salsa

Homocysteine• Amino Acid in the blood• Produced during cellular metabolism• High levels in the blood is related to

CAD, Stroke, and Peripheral Vascular Disease• Believed to damage cells that line arteries• Correlates to early, serious heart disease• Folate, Pyridoxine (B6), and Cobalamin

(B12) help convert homocysteine to other nondamaging amino acids

Minerals• Inorganic and vital to human life• Out of 117 known elements, 25 are essential to life• The human body requires a variety of minerals in

different amounts to perform numerous metabolic tasks• Classes based on how much body has– Ex. Calcium makes up about 2% of total body

weight

• Major minerals make up 60% to 80% of all inorganic material in the body.

• Trace elements make up less than 1% of the body’s inorganic material

Minerals

• RDAs have not been set for all minerals.

• Als or ULs have been set for almost all essential minerals without RDAs.

• Mineral supplementation is still under much debate.

Functions of Minerals• Constituents of enzymes,

hormones, and vitamins• Provide structure in

formation of bones and teeth• Synthesize the biological

macronutrients (carbohydrates, fat, protein)

Classes of MineralsMajor

• Intake of > 100 mg/day• 7 essential to life–Calcium–Phosphorous–Sodium–Potassium–Magnesium–Chloride–Sulfur

Trace • Intake < 100 mg/day• 13 essential to life:– Iron– Iodine– Zinc– Selenium– Fluoride; Copper;

Manganese; Chromium; Molybdenum; Cobalt; Boron; Vanadium; Nickel

Calcium• USDA: One of the minerals most likely to be deficient in a

typical diet

• Men consume 25% more calcium than females

• Functions:

– Bone and Teeth Formation

– Blood Clotting

–Muscle and Nerve Action

–Metabolic Reactions:

• Absorption of B12 (Cobalamin)

• Activation of pancreatic lipase

• Secretion of insulin

• Cell membrane permeability

Calcium• Deficiency Disease:– Osteoporosis: Decreased bone density

– Tetany: Muscle spasms

• Food Source: Dairy, green leafy vegetables, fish with bones

• Requirements: – 9-18 years: 1300 mg

– 19-50 years: 1000 mg

– > 50 years: 1200 mg

• Toxicity Causes:– Increased risk of developing kidney stones

Phosphorous• Functions:

– Bone and tooth formation

– Energy metabolism

• Oxidation of carbohydrate, fat, and protein

• Energy and protein metabolism

• Cell function and genetic inheritance

–Component of enzymes, thiamin, DNA/RNA

– Acid-base balance

• Deficiency and toxicity is rare

• Food Sources: Dairy, meat, fish, and eggs• Requirements: 700 mg/day

Sodium• One of the most abundant minerals in the body

• Functions:

–Water balance

–Acid-base balance

– Transmission of nerve impulses to muscles

–Glucose absorption

• Deficiency Causes: Dehydration

• Toxicity Causes: Salt sensitivity and hypertension

• Food Sources: Table salt, cured meats, processed foods

• Requirements: AI: 1.5 g/day

Potassium• Functions:

–Water balance

–Metabolic reactions

•Conversion of blood glucose to glycogen

• Storage of nitrogen in muscle protein

• Production of energy (ATP)

–Transmission of nerve impulses to muscles

– Insulin release

–Blood pressure

Potassium• Deficiencies more likely to occur during clinical

situations such as prolonged vomiting or diarrhea, during use of diuretic drugs, during use of hypertension drugs, as a result of severe malnutrition, or after surgery

• Extremely high potassium levels results in a fatal arrhythmia

• Food Sources: Oranges, bananas, broccoli, leafy green vegetables, whole grains, and dairy

• Requirements: AI: 4.7 g/day

Magnesium• Found in all body cells

• Functions:

– General metabolism

• Necessary catalyst for ~300+ reactions in cells

– Protein synthesis

• Activates amino acids

• Role in synthesis and maintenance of DNA

–Muscle action

– Basal metabolic rate

• Influences secretion of thyroxine (hormone produced by the thyroid glands to regulate metabolism )

Magnesium

•Deficiency and Toxicity is rare• Food Sources: Most fruits, except

bananas, milk, meat, fish, nuts, soybeans, cocoa, peas, green vegetables

• Requirements–~300 to 400 mg/day

Chloride• Functions:

–Digestion

•Key element in hydrochloric acid secretion

•Chloride is needed for digestion of all foods through hydrochloric acid.

–Respiration

• Deficiency and Toxicity is rare

• Food Sources: Table Salt

• Requirements: AI: 2.3 g/day

Sulfur• Present in all body cells

• Functions:

– Hair, skin, and nails

– General metabolic functions

• High-energy bond

• Transfer energy

– Vitamin structure

– Collagen structure

• Deficiency and Toxicity not stated• Food Source: Meat, nuts, soy, fish, cheese, eggs

• Requirements: Not stated

Iron• Functions:

– Hemoglobin synthesis

• 70% of the body’s iron occurs in red blood cells

• Contains Heme – non-protein part of structure

• Transports O2 from lungs to body

• Carries O2 to cells for oxidation and metabolism

Iron• Functions Cont’d

–General metabolism

• Proper glucose metabolism

• Antibody production

• Drug detoxification in the liver

• Collagen and purine (provide part of the chemical structure of our genes) synthesis

• Conversion of beta-carotene to vitamin A

• Deficiency Disease:

–Anemia: A decrease in the number of red blood cells, a drop in the amount of hemoglobin, or both

Iron• Food sources occur in two forms: – Heme and Nonheme

– Heme Food Sources

• Animal sources only

• Meat, liver, poultry, eggs, oysters, salmon, tuna; 40% of iron in animal sources

– Absorption Rate: rapid

• Non-Heme Food Sources

• Animal and plants (dark leafy green vegetables)

– Absorption Rate: slow (harder for body to absorb)

• Body absorbs iron more easily when taken with Vitamin C

Iron• Requirements:

– 8 to 11 mg/day for males

– 8 to 18 mg/day for females (menstruation and pregnancy)

• Toxicity Causes:– 1 dose (20-60 mg/day) can be fatal–Causes: Nausea, vomiting, diarrhea– Severe cases = damage to cardiovascular and central

nervous system, kidney, and liver–Hemochromatosis: Congenital disease results in iron

overload even though iron intake is within normal range

Iodine• Functions:

– Participation in thyroid gland’s synthesis of thyroxine which regulates basal metabolic rate (BMR)

• Deficiency Disease:

– Cretinism: Results from a mother eating insufficient amounts of iodine during fetal development causing physical deformity, dwarfism, and mental retardation

– Hypothyroidism: Lowers BMR and symptoms are coarse hair, dry skin, weight gain, cold tolerance, and a low husky voice

– Graves Disease (hyperthyroidism): High BMR, weight loss, hand tremors, nervousness, increased appetite, heat tolerance

Iodine• Deficiency Disease

Cont’d:

• Goiter: Enlargement of the thyroid gland

• Food Sources:

– Seafood, iodized table salt

– Varies depending on iodine content of soil

• Requirements:

– 150 mcg/day

Zinc• Functions: –Enzyme constituent; more than 200 zinc

containing enzymes

–Present in leukocytes (white blood cells)

• Deficiency Causes:–Dwarfism

–Impaired taste and smell

–Poor wound healing, hair loss, diarrhea, and skin irritation

Zinc• Food Sources:

– Beef, lamb, pork, turkey, chicken, lobster, clams, salmon, milk, cheese, peanuts, beans, wholegrain cereals, brown rice, whole wheat bread, potato and yogurt.

– Pumpkin seeds offer one of the most concentrated non-meat food sources of zinc

• Requirements:

– 11 mg/day for males

– 8 mg/day for females

Selenium• Present in all body tissues except adipose tissue

• Highest concentration are in the liver, heart, kidneys, and spleen (organ under the diaphragm that creates lymphocytes for the destruction and recycling of old red-blood cells)

• Functions:

–Works with specific proteins as an essential part of an antioxidant enzyme, glutathione peroxidase, which protects cells and their lipid membranes from oxidative damage.

– Part of the protein center of teeth and participates in the regulation of thyroid hormone action and vitamin C activity.

Selenium• Deficiency Causes:

– Compromised immune system

– Decreased ability to fight infection

– Risk for developing cancer

– Keshan Disease: Heart failure in young children and women of childbearing age

• Food Sources:

– Seafood, kidney, liver; fruits and vegetables contain little

• Requirements:

– RDA: 55 mcg/day

• Toxicity Causes:– Brittle hair and nails, GI upset, skin rash

Electrolytes• Electrically charged particles dissolved in

body fluids

–Sodium, Chloride, Potassium

• Establish proper electrical gradient across cell membranes

• Modulate fluid exchange within body’s fluid compartments

• Regulate acid and base qualities of body fluids

Supplementation• If vitamin levels are adequate, supplementation is

not necessary

• Several mega doses of a single mineral may create deficiencies of another

• Life Cycle Needs:– Pregnancy and lactation

– Adolescence

– Adulthood

• Clinical Needs:– Iron-deficiency anemia

– Zinc deficiency

Building A Super Salad• Each student will bring in a component of a salad

representing a specific micronutrient

–E.g., Carrots, Broccoli, Spinach, Tomatoes, Almonds, Sunflower Seeds, Sesame Seeds, Soy Nuts, Ground Flaxseed, Wheat Germ, Raisins, Walnuts, Olives, Garbanzo Beans, Chick Peas, Pumpkin Seeds

•  Avoid the iceberg lettuce, it’s extremely low in micronutrients