Vitamins and Nutrition Quiz

Vitamins Lecture 7

• Vitamins are essential, non-caloric organic nutrients required in small amounts
• Vitamins do not supply energy
• They cannot be synthesized by the body; obtained through diet, rumen bacteria, or sun
• Vitamins are individual units, not linked together like carbohydrates, proteins, and fats
• Required for growth, maintenance, reproduction, and lactation

Learning Objectives

• Identify the meaning of vitamins
• Compare fat-soluble vs. water-soluble vitamins
• Discuss fat-soluble vitamins: roles, food sources, function, deficiency, and toxicity
• Discuss water-soluble vitamins: roles, food sources, function, deficiency, and toxicity

What are Vitamins?

• Vitamins are essential, noncaloric organic nutrients required in small amounts.
• Vitamins do not supply energy.
• They cannot be synthesized by the body.
• They must be obtained from outside sources like diet, rumen bacteria, and the sun.
• Vitamins are individual units; they are not linked together.
• They are needed for growth, maintenance, reproduction, and lactation.

Classification of Vitamins

• Fat-soluble vitamins: A, D, E, and K
• Water-soluble vitamins: C and B complex

Characteristics of Fat- Soluble and Water-Soluble Vitamins

Fat-Soluble Vitamins

• Play diverse roles in the body
• Vitamins A and D act as hormones
• Vitamin E protects tissues from destructive oxidative reactions
• Vitamin K is essential for blood clotting and bone health

Vitamin A

• A group of similar compounds called retinoids
• 3 forms: retinol (most active), retinal, and retinoic acid
• About 10% of plant-derived carotenoids (like beta-carotene) are converted into retinoids in the body
• Carotenoids are pigments that give plants their yellow, orange, and red colors

Functions of Vitamin A

• Vision (Retinol generates pigments for the retina, maintains eye coverings and linings)
• Regulation of gene expression (Reproduction)
• Required for cell growth and division (Epithelial cells, bones, and teeth)
• Development of immune cells
• Healthy skin

Vitamin A Recommendations and Sources

• Dietary Reference Intake (DRI) for vitamin A is based on body weight.
• Men need approximately 900 micrograms
• Women need approximately 700 micrograms. Higher during lactation
• Food sources:
  • Animal sources (eggs, meat, cheese, milk, liver, kidney)
  • Plant sources (carrots, sweet potatoes, pink grapefruit, apricots, broccoli, spinach, pumpkin)
  • Human body converts all dietary forms of vitamin A into retinol

Signs of Vitamin A Deficiency

• Night blindness, exophthalmia
• Decreased resistance to infections
• Extremely dry skin, hair, or nails
• Anemia
• Retarded growth in children

Vitamin A Toxicities

• Single large doses of supplements or eating excessive amounts of liver
• Symptoms: dry, itchy skin, headaches, fatigue, hair loss, blurred vision, loss of appetite, swelling of the brain, joint pain, skin discoloration, liver damage, and coma
• Excessive vitamin A during pregnancy can injure the heart, spinal cord, and other tissues, potentially causing birth defects

Vitamin E

• Alpha-tocopherol is the only form recognized to meet human requirements
• Antioxidant
• Stops free radical formation
• Discourages some types of cancer
• Necessary for normal nerve development
• Promotes normal growth and development
• Inhibits blood clotting
• Aids in wound healing
• Boosts the immune system

Vitamin E Recommendations and Sources

• 15 milligrams per day for adults
• Sources: Wheat germ oil, vegetable oils, nuts and seeds, whole grains, egg yolk, and leafy green vegetables
• Vitamin E is easily destroyed by heat

Vitamin E Deficiency

• Insufficient levels are rare, primarily in diets extremely low in fat for years
• High-risk groups: malabsorption disorders (Crohn's disease or cystic fibrosis), premature babies
• Deficiency symptoms: red blood cell breakage, nerve damage, loss of muscle coordination, impaired vision and speech
• Toxicities: more than 1000 milligrams/day can augment the effect of anti-clotting medication.

Vitamin K

• Produced by bacteria in the large intestine
• Function: promotes synthesis of blood clotting and bone formation
• Deficiency symptoms: hemorrhaging, rare in infants after prolonged antibiotic therapy, or patients with decreased bile production

Vitamin K Recommendations and Sources

• Toxicity symptoms are not known if less than 1000 mg/day intake.
• Sources: bacterial synthesis in the digestive tract, milk, leafy green vegetables, cabbage-type vegetables
• For men: 120 micrograms a day
• For women: 90 micrograms a day

Vitamin D

• Synthesized in the body with the help of sunlight
• The skin synthesizes vitamin D when exposed to sunlight
• Vitamin D is not an essential nutrient.

Vitamin D Factors Affecting Synthesis

• Season: Long winters decrease synthesis
• Sunscreen use: Prevents sunlight absorption, decreasing synthesis
• Skin color: Darker skin needs more time for exposure to sunlight, decreased synthesis
• Time of day: Vitamin D3 synthesis increases in the morning
• Age: Older people have decreased synthesis
• Clothing: Wearing clothing that covers the skin decreases synthesis

Vitamin D Function

• Essential for proper utilization of calcium and phosphorus needed to produce healthy bones
• Plays a role in muscle function and the immune system
• Might help prevent colon, prostate and breast cancers
• Might help prevent and treat diabetes, heart disease, high blood pressure, and multiple sclerosis

Vitamin D Deficiency Diseases

• Rickets (Children develop bowed legs, weak, and deformed bones)
• Osteomalacia (Adults, their bones become soft, flexible, weak, and deformed)
• Toxicities symptoms:
  • Increase blood calcium
  • Calcification of soft tissues (blood vessels, kidneys, heart, lungs, tissues in joints)
  • Loss of appetite, nausea, vomiting, frequent urination, fatigue, back pain, and irregular heartbeat

Vitamin D Sources and Recommendations

• Synthesized in the body with the help of sunlight
• Less than 30 minutes of sun exposure to arms and legs increases blood levels of vitamin D3
• Fortified milk, margarine, butter, cereals, beef, egg yolk, liver, fatty fish
• 1 to 70 years old need 15 micrograms daily; 71 and older need 20 micrograms per day

Water-soluble Vitamins

• Water-soluble vitamins are absorbed directly into the bloodstream, where they function.
• Most aren't stored, but are readily excreted via the urine.

Vitamin C

• Function: protects the body from free radicals, forms connective tissues (collagen), aids in wound healing, aids in iron absorption, boosts gums, helps fight infections, aids in preventing heart disease
• Deficiency signs: Scurvy (bleeding gums, loosened teeth, swollen ankles and wrists, and tiny red spots in skin), fatigue and joint pain, reduced resistance to colds and infections, slow healing of wounds and fractured bones, anemia.
• Toxicity: over 1000 mg/day; symptoms: nausea, abdominal cramps, diarrhea, headache, fatigue, insomnia, rashes, urinary tract problems, kidney stones
• Sources: citrus fruits (oranges, grapefruits, lemons, limes); cabbage-type vegetables, dark green vegetables (broccoli); strawberries; berries; melons; papayas; mangoes; potatoes; tomatoes; guava
• Recommended Dietary Intake for adults: 90 mg per day (men), 75 mg per day (women), smokers + 35mg per day

B Complex

• Thiamin B1, Riboflavin B2, Niacin B3, Folate B9, B6, B12, Biotin B7, and Pantothenic acid
• Functions: aid in the metabolism of carbohydrates, lipids, and amino acids; part of coenzymes; and activate enzymes.
• Some detailed notes on specific B vitamins follows below

Thiamin B1

• Function: Important in glucose metabolism; cofactor for enzymes breaking down glucose for energy production. Plays a role in neurotransmitter synthesis; required for RNA, DNA, and ATP synthesis
• Food sources: whole-grain, fortified, or enriched grain products; moderate amounts in all nutritious food
• Toxicity: None reported

Riboflavin B2

• Function: Essential component of flavoproteins (coenzymes) involved in carbohydrate, lipid, and protein metabolism; gives a bright yellow color to riboflavin.
• Food sources: Milk and dairy products (yogurt, cheese), enriched or whole grains, liver

Niacin B3

• Function: Like thiamin and riboflavin, participates in energy metabolism of every cell.
• Amino acid tryptophan is abundant in protein. Converted into niacin in the body.
• Deficiency disease: Pellagra (dermatitis, diarrhea, dementia, and death)
• Food sources: foods high in vitamin B3 niacin (broccoli, peanuts, chicken, mushrooms, bell peppers, kidney beans)

Vitamin B6 (Pyridoxine)

• Function: Part of coenzyme needed in amino acid and fatty acid metabolism. Essential for converting methionine into cysteine and tryptophan into niacin and serotonin. Helps make hemoglobin, releases stored glucose, and develops fetal brain/nervous system.
• Deficiency symptoms: Weakness, depression, confusion, irritability, convulsions, insomnia, and greasy dermatitis (the skin is greasy and flaky).
• Food sources: Meat, fish, poultry (protein-rich foods), starchy vegetables, fruits, and leafy green vegetables

Folate B9 (Folic Acid)

• Function: Required for making RNA and DNA, and works with B12 to form hemoglobin, Essential for amino acid methionine synthesis
• Deficiency: anemia (large-cell type), smooth red tongue, mental confusion, weakness fatigue, irritability, headache; helps prevent neural tube defects like spina bifida
• Food sources: fortified grains, leafy green vegetables, legumes, seeds, liver

Vitamin B12 (Cobalamin)

• Function: Part of coenzymes used in new cell synthesis; helps maintain nerve cells, helps break down fatty acids, essential for hemoglobin synthesis, converts folate to active form.
• Deficiency disease: pernicious anemia (large and immature red blood cells), anemia, fatigue, paralysis/nerve damage in the fetus
• Food sources: animal products (meat, poultry, fish, shellfish, milk, cheese, eggs), fortified cereals
• Toxicity: None reported

Deficiency Diseases: Beriberi & Wernicke Korsakoff syndrome

• Beriberi: two types (wet and dry), causes muscle wasting, edema, fatigue, confusion, movement impairment, pain in lower extremities. Swelling, and heart failure.
• Wernicke Korsakoff syndrome: confusion, loss of coordination, vision changes, hallucinations, and may lead to coma and death. Specific to alcoholics due to high alcohol intake.

Test your knowledge on vitamins, their functions, recommended intakes, and deficiency diseases with this engaging quiz. Explore key facts about Vitamin D, E, K, and C to enhance your understanding of nutrition and health.