Mineral Absorption and Bioavailability
40 Questions
2 Views

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to lesson

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What is a potential consequence of excessive phosphorus intake?

  • Bone gain
  • Magnesium toxicity
  • Bone loss (correct)
  • Increased calcium levels
  • What is the primary function of magnesium in the body?

  • To regulate blood pressure
  • To regulate body temperature
  • To act as an enzyme cofactor (correct)
  • To store energy in the muscles
  • What is a characteristic of magnesium deficiency?

  • It is very common in adults
  • It only affects the bones
  • It always leads to toxicity
  • It is rare in healthy individuals (correct)
  • What is the primary function of sodium in the body?

    <p>To regulate plasma volume and body water content</p> Signup and view all the answers

    What is a common source of sodium in the diet?

    <p>Table salt</p> Signup and view all the answers

    What is a potential consequence of sodium deficiency?

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

    What is a characteristic of phosphorus toxicity?

    <p>It stimulates secondary hyperparathyroidism</p> Signup and view all the answers

    What is a characteristic of magnesium toxicity?

    <p>It causes depressed deep tendon reflexes</p> Signup and view all the answers

    What affects the absorption of minerals?

    <p>Other nutrients and compounds in the diet</p> Signup and view all the answers

    What is the effect of excess iron on zinc absorption?

    <p>It reduces zinc absorption</p> Signup and view all the answers

    What is the role of selenium, manganese, and zinc in the body?

    <p>They form part of the body's defenses against free-radicals</p> Signup and view all the answers

    What is the concern with excess intake of minerals?

    <p>It may cause mineral imbalances or have other side-effects</p> Signup and view all the answers

    What is the classification of calcium, phosphorus, and magnesium?

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

    Why are patients with biliary stones advised not to eat tomatoes?

    <p>Because tomatoes are high in oxalate</p> Signup and view all the answers

    What is the effect of malabsorption of lipids on calcium absorption?

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

    What is the common problem often affecting women and young children throughout the world?

    <p>Iron deficiency anaemia</p> Signup and view all the answers

    What is a risk factor for heart disease and stroke associated with excessive sodium intake in the diet?

    <p>Raised blood pressure</p> Signup and view all the answers

    What is the main function of potassium in the body?

    <p>Maintenance of water and electrolyte balance</p> Signup and view all the answers

    Which of the following foods is a rich source of potassium?

    <p>Dried fruits</p> Signup and view all the answers

    What is a potential consequence of potassium deficiency?

    <p>Muscular weakness</p> Signup and view all the answers

    What is the main function of chloride in the body?

    <p>Formation of gastric fluid</p> Signup and view all the answers

    What is the role of the chloride-bicarbonate exchanger in the body?

    <p>Increases the permeability of the erythrocyte membrane to HCO3-</p> Signup and view all the answers

    What is the role of chloride in CO2 transport to the lungs?

    <p>Facilitating the transport of CO2 from tissues to the lungs</p> Signup and view all the answers

    What is a potential consequence of excessive potassium intake?

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

    What is the primary function of calcium in the body?

    <p>To form bones and teeth</p> Signup and view all the answers

    What is the normal range of serum calcium levels?

    <p>8.5-10.5 mg/dL</p> Signup and view all the answers

    What is the role of parathyroid hormone in calcium regulation?

    <p>It increases calcium levels in the blood</p> Signup and view all the answers

    What is the consequence of long-term dietary calcium insufficiency?

    <p>Net loss of calcium from bones</p> Signup and view all the answers

    What is the condition caused by vitamin D deficiency in adults?

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

    What is the role of calcium-binding proteins in calcium absorption?

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

    Why is adequate calcium intake important during lactation?

    <p>It supports the growth of the infant</p> Signup and view all the answers

    What is the term for minerals required in smaller quantities (less than 100 mg/day)?

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

    What happens to HCO3- in the lungs?

    <p>It is converted to CO2 and exhaled</p> Signup and view all the answers

    What is the role of the chloride-bicarbonate exchanger?

    <p>To facilitate the movement of HCO3 across the erythrocyte membrane</p> Signup and view all the answers

    What is the result of a chloride deficiency?

    <p>Hypochloremic alkalosis</p> Signup and view all the answers

    What is sulfur a part of?

    <p>Many proteins and sulfolipids</p> Signup and view all the answers

    What is a major source of sulfur in the diet?

    <p>Protein sources containing sulfur amino acids</p> Signup and view all the answers

    What is a function of sulfur in the body?

    <p>Part of many proteins and coenzymes</p> Signup and view all the answers

    What is the function of the chloride-bicarbonate exchanger in the erythrocyte?

    <p>To facilitate the movement of HCO3 across the erythrocyte membrane</p> Signup and view all the answers

    What is the consequence of a lack of chloride in the transport of HCO3?

    <p>HCO3 transport stops</p> Signup and view all the answers

    Study Notes

    Factors Affecting Mineral Bioavailability and Absorption

    • Absorption of minerals is influenced by various factors, including other nutrients and compounds in the diet.
    • Oxalate and phytate, found in some foods, chelate divalent cations, reducing the absorption of minerals like calcium, iron, and zinc.
    • Phytate is commonly found in cereals, especially wheat, while oxalate is found in vegetables, particularly tomatoes.
    • Patients with biliary stones (calcium oxalate) are advised to avoid eating tomatoes.
    • Malabsorption of lipids can lead to malabsorption of calcium (Ca-palmitate, Ca-stearate).

    Mineral Interactions and Deficiencies

    • Excess intake of one mineral can block the absorption of another, e.g., excess iron reduces zinc absorption.
    • Vitamin C increases iron absorption when consumed during the same meal.
    • Iron deficiency anemia is a common problem, particularly affecting women and young children worldwide.
    • Deficiencies of other minerals are rare in Western societies, but excess intakes can be a concern (e.g., sodium).
    • Selenium, manganese, and zinc may help protect against free radicals and diseases like cancer and heart disease.

    Classification of Minerals

    • Minerals are classified into macrominerals (needed in larger amounts, >100mg/d) and microminerals (needed in smaller amounts, <100mg/d).
    • Macrominerals include calcium, phosphorus, magnesium, sodium, potassium, and chloride.
    • Microminerals, also known as trace minerals, include iron, zinc, iodine, fluoride, selenium, and copper.

    Calcium (Ca)

    • Calcium is the most abundant mineral in the body, with most of it found in bones.
    • Calcium plays a crucial role in essential processes, including nerve and muscle function, blood clotting, and intracellular signaling.
    • Calcium absorption requires calcium-binding protein, and its level in the blood is regulated by parathyroid hormone and vitamin D.
    • Low calcium intake can lead to osteomalacia (softening of bones) and rickets in children.

    Phosphorus (P)

    • Phosphorus is essential for bone and tooth structure, energy metabolism, and electrolyte balance.
    • Phosphorus deficiency is rare, but an excessive intake can lead to calcium being pulled from bones, causing bone loss.

    Magnesium (Mg)

    • Magnesium is present in all tissues, including bone, and is required for enzyme cofactors, bone and tooth structure, and normal energy metabolism.
    • Magnesium deficiency can lead to muscle weakness, electrolyte imbalance, and bone loss.

    Sodium (Na)

    • Sodium is the principal cation in extracellular fluid and helps regulate plasma volume, electrolyte balance, nerve function, and energy utilization.
    • Excessive sodium intake is associated with an increased risk of hypertension and heart disease.

    Potassium (K)

    • Potassium is the principal cation in intracellular fluid and is essential for water and electrolyte balance, nerve function, and cell signaling.
    • Potassium has a beneficial blood pressure-lowering effect in people with hypertension.
    • Potassium deficiency can lead to muscular weakness, mental confusion, and paralysis.

    Chloride (Cl)

    • Chloride is an anion closely connected with sodium in food, body tissues, and body fluids.
    • Chloride is essential for the formation of gastric fluid, fluid and electrolyte balance, and acid-base balance.
    • Chloride is involved in CO2 transport to the lungs from tissues and is essential for the chloride-bicarbonate exchanger system.

    Sulfur

    • Sulfur is part of many proteins, sulfolipids, conjugated bile acids, and coenzyme A.
    • Sulfur is also present in thiamine, biotin, and insulin.
    • Most sulfur in the diet comes from protein sources containing sulfur amino acids like cysteine, cystine, and methionine.

    Studying That Suits You

    Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

    Quiz Team

    Description

    This quiz explores the factors that affect the absorption and bioavailability of minerals, including the impact of oxalate and phytate on calcium, iron, and zinc absorption.

    More Like This

    Mineral Nutrition Quiz
    20 questions

    Mineral Nutrition Quiz

    MesmerizedMoldavite7389 avatar
    MesmerizedMoldavite7389
    Chapter 9: Minerals
    30 questions
    Nutrition Chapter 12: Water and Minerals
    42 questions
    Trace Minerals and Their Sources
    21 questions
    Use Quizgecko on...
    Browser
    Browser