Vitamins: Functions and Daily Requirements
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Questions and Answers

Which vitamin is classified as fat-soluble and is also acknowledged for its potential toxicity?

  • Vitamin B12
  • Vitamin C
  • Vitamin A (correct)
  • Folic Acid

    • What is the primary reason some water-soluble vitamins are less toxic than fat-soluble vitamins?

  • They are more fragile and easily destroyed.
  • Excess amounts are excreted by the body. (correct)
  • They are less important for body function.
  • They are absorbed in the fat tissues.

    • Which vitamin is stored in significant amounts within the liver and can maintain a person without intake for several months?

  • Vitamin D
  • Vitamin C
  • Vitamin B6
  • Vitamin A (correct)

    • Which of the following is true about the storage of most water-soluble vitamins?

    <p>They lack storage and are excreted quickly.</p> Signup and view all the answers

    Which vitamin can cause symptoms of deficiency within a few weeks and potentially lead to death from scurvy in a few months?

    <p>Vitamin C</p> Signup and view all the answers

    Beta-carotene is categorized as which type of vitamin component?

    <p>A precursor or provitamin.</p> Signup and view all the answers

    What distinguishes vitamins from macronutrients in terms of caloric contribution?

    <p>Vitamins do not provide any calories.</p> Signup and view all the answers

    Which of the following vitamins has a significant storage time of 2 to 4 months in the body?

    <p>Vitamin D</p> Signup and view all the answers

    What primary symptom results from severe thiamine deficiency due to weakened cardiac muscle?

    <p>Cardiac failure</p> Signup and view all the answers

    Which condition is commonly associated with niacin deficiency that includes symptoms like diarrhea and dermatitis?

    <p>Pellagra</p> Signup and view all the answers

    What physiological change occurs due to thiamine deficiency that affects blood return to the heart?

    <p>Increased venous return</p> Signup and view all the answers

    Which vitamin deficiency can lead to muscle weakness and poor glandular secretion?

    <p>Niacin</p> Signup and view all the answers

    What is a common gastrointestinal symptom due to severe thiamine deficiency?

    <p>Severe constipation</p> Signup and view all the answers

    Which vitamin is primarily synthesized from the amino acid tryptophan?

    <p>Niacin</p> Signup and view all the answers

    Which enzyme is formed by riboflavin combining with phosphoric acid?

    <p>FAD</p> Signup and view all the answers

    What consequence does a diet high in corn have on niacin absorption?

    <p>Exacerbation of pellagra</p> Signup and view all the answers

    What is the primary metabolic role of pantothenic acid (Vitamin B5) in the body?

    <p>Conversion of pyruvic acid into acetyl-CoA</p> Signup and view all the answers

    What effect does ascorbic acid deficiency have on the body?

    <p>Weakening of collagen fibers</p> Signup and view all the answers

    What condition is primarily caused by vitamin D deficiency in children?

    <p>Rickets</p> Signup and view all the answers

    Which of the following is NOT a function of vitamin D?

    <p>Regulates blood sugar levels</p> Signup and view all the answers

    What is a likely consequence of long-term ascorbic acid deficiency?

    <p>Increased fracture risk</p> Signup and view all the answers

    Which of the following describes a key symptom of scurvy?

    <p>Petechial hemorrhages</p> Signup and view all the answers

    How does vitamin D specifically aid in the formation of a calcium binding protein?

    <p>Activating intestinal epithelial cells</p> Signup and view all the answers

    What is a negative effect of inadequate vitamin D regarding bone health?

    <p>Prevents calcium absorption</p> Signup and view all the answers

    What is one of the key functions of Vitamin A in the body?

    <p>Formation of retinal pigments in the eye</p> Signup and view all the answers

    What does a deficiency of Vitamin A contribute to in terms of epithelial tissue?

    <p>Stratification and keratinization</p> Signup and view all the answers

    How does thiamine (Vitamin B1) primarily function in the metabolism of carbohydrates?

    <p>As a coenzyme in decarboxylation reactions</p> Signup and view all the answers

    Which of the following conditions is associated with thiamine deficiency?

    <p>Beriberi</p> Signup and view all the answers

    What is a consequence of thiamine deficiency on neuronal tissue?

    <p>Decreased glucose utilization</p> Signup and view all the answers

    Vitamin A is often referred to as an 'anti-infection' vitamin because it helps prevent infections in which of the following systems?

    <p>Epithelial structures like conjunctivae and respiratory passages</p> Signup and view all the answers

    Which symptom is NOT associated with Vitamin A deficiency?

    <p>Bone fragmentation</p> Signup and view all the answers

    Thiamine deficiency leads to lesions in which part of the human body?

    <p>Central and peripheral nervous systems</p> Signup and view all the answers

    What is one of the main symptoms of severe riboflavin deficiency?

    <p>Depression of oxidative processes</p> Signup and view all the answers

    Which of the following roles is attributed to vitamin B12?

    <p>Coenzyme in cell synthesis</p> Signup and view all the answers

    What condition is primarily caused by a deficiency of intrinsic factor?

    <p>Pernicious anemia</p> Signup and view all the answers

    Which of the following is a significant consequence of folic acid deficiency?

    <p>Macrocytic anemia</p> Signup and view all the answers

    Which tissue specific process does vitamin B6 primarily aid in?

    <p>Transamination for amino acid synthesis</p> Signup and view all the answers

    What effect is caused by riboflavin deficiency?

    <p>Dermatitis and nausea</p> Signup and view all the answers

    Which of the following statements about vitamin B12 is FALSE?

    <p>It directly influences iron metabolism.</p> Signup and view all the answers

    What is the primary nutritional implication of vitamin B6 deficiency?

    <p>Neurological disturbances and seizures</p> Signup and view all the answers

    Study Notes

    Physiological Functions of Vitamins

    • Vitamins are essential for normal body functioning, growth, and maintenance of tissues.
    • Vitamins are needed in very small amounts.
    • Milligrams (mg) are 1/1000 of a gram.
    • Micrograms (mcg) are 1/1,000,000 of a gram.
    • Lack of vitamins can cause metabolic deficiencies.
    • Daily requirements vary based on body size, growth rate, exercise, and pregnancy.

    Daily Requirements

    • Vitamins are not a source of energy.
    • Specific amounts are needed for proper body function.
    • Different vitamins have different required daily amounts.

    Vitamin Amounts

    • Vitamin A: 5000 IU
    • Thiamine: 1.5 mg
    • Riboflavin: 1.8 mg
    • Niacin: 20 mg
    • Ascorbic acid: 45 mg
    • Vitamin D: 400 IU
    • Vitamin E: 15 IU
    • Vitamin K: 70 µg - (micrograms)
    • Folic acid: 0.4 mg
    • Vitamin B12: 3 µg
    • Pyridoxine: 2 mg
    • Pantothenic acid: Unknown amount

    Major Roles of Vitamins

    • Antioxidants: protect cells from damage (Vitamin E, C)
    • Coenzymes: assist in chemical reactions (8 B vitamins)
    • Vision: crucial for vision (Vitamin A)
    • Bone health: essential for strong bones (Vitamin D)
    • Blood clotting: necessary for blood clotting (Vitamin K),
    • Cellular growth: necessary for growth of most cells (Vitamin A)

    Types of Vitamins

    • Fat-soluble vitamins: Vitamins A, D, E, and K.
      • Absorbed with dietary fat
      • Stored in liver and fatty tissue
      • Toxicity more likely, especially excess Vitamin A and D
    • Water-soluble vitamins: Vitamins C and the 8 B complex vitamins.
      • Little stored (except B12) in the body
      • Less toxic if excess is consumed.
      • Sensitive to heat, light, and alkaline conditions during cooking.

    Vitamin Storage

    • Vitamins are stored to some degree in all cells, but some vitamins are stored more significantly in the liver.
    • Vitamin A: stored for 5-10 months.
    • Vitamin D: stored for 2-4 months.
    • Water-soluble vitamins have less storage.

    Vitamin A

    • Active forms include retinol, retinal, and retinoic acid.
    • Beta-carotene is a precursor (provitamin)
    • Beta-carotene produces two molecules of vitamin A when absorbed.
    • Found in animal tissues (retinol) and plant foods (provitamins) as carotenoids (yellow & red pigments).
    • Essential for vision, cell growth and other body functions.

    Vitamin A Deficiency

    • Results in visual problems (night blindness).
    • Can affect growth of cells and tissues.
    • Epithelial cells (lining of organs and body surfaces) are affected.
    • Skin may become stratified and keratinized.
    • Can impact skin and eyes.

    Other Vitamins

    • Thiamine (B1): coenzyme for carbohydrate metabolism; deficiency causes beriberi (various symptoms).
    • Niacin (B3): coenzyme; deficiency causes pellagra (symptoms like skin problems, dementia, and diarrhea)
    • Riboflavin (B2): coenzyme in oxidative processes; deficiency can mimic niacin deficiency.
    • Vitamin B12: coenzyme for cell synthesis, folate absorption, and nerve function; deficiency can cause pernicious anemia and nerve damage.
    • Folic acid (B9): critical for DNA synthesis and red blood cell production; deficiency causes macrocytic anemia, and impacts growth.
    • Pyridoxine (B6): involved in amino acid metabolism; deficiency causes neurological problems.
    • Pantothenic acid (B5): part of coenzyme A, fundamental to metabolic pathways; deficiency symptoms not well documented.
    • Ascorbic acid (Vitamin C): essential for collagen synthesis, wound healing, and immune function; deficiency causes scurvy.
    • Vitamin D: regulates calcium and phosphate levels.
    • Vitamin E: antioxidant; deficiency rare but can affect fertility and cause muscle and nerve problems.
    • Vitamin K: important in blood clotting; deficiency rare.

    Vitamin Deficiencies

    • Specific diseases (and symptoms) can occur when a person does not have enough of a particular vitamin.
    • Examples of deficiencies: -Rickets (Vitamin D) -Scurvy (Vitamin C) -Pellagra (Niacin) -Beriberi (thiamine)

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    Description

    This quiz covers the essential physiological functions of vitamins and their daily requirements for proper body functioning. It explores the unique roles each vitamin plays, the consequences of deficiencies, and the specific daily amounts needed for optimal health.

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