Minerals

Module 10 - Minerals

Learning Objectives

• Differences between Macrominerals and Microminerals:
    - Macrominerals:
      - Present in greater amounts in the body.
      - Recommended intake is ≥100 mg per day.
      - Examples include: calcium, phosphorus, potassium, sulfur, sodium, chloride, magnesium.
    - Microminerals (Trace Minerals):
      - Recommended intake is <100 mg per day.
      - Examples include: iron, copper, manganese, iodine.

• Calcium:
    - Regulation of Blood Calcium Levels:
      - Blood calcium levels are regulated by Vitamin D and Parathyroid hormone.   - Functions of Calcium in the Body:
      - Muscle contraction.
      - Nerve transmission.
      - Involvement in blood coagulation.
    - Dietary Sources of Calcium:
      - Dairy products (milk, cheese, yogurt).
      - Canned sardines and salmon with bones.     - Green leafy vegetables (excluding spinach).

• Roles/Functions of Other Minerals:
    - Magnesium:
      - Involved in over 300 biochemical reactions.
    - Phosphorus:
      - Part of DNA and RNA, ATP, and phospholipids.
      - Crucial for bone health.
    - Sulfur:
      - Primarily found in amino acids methionine and cysteine.

• Dietary Sources of Magnesium:
    - Green leafy vegetables (spinach, Swiss chard), nuts, seeds, whole grains, and legumes.

• Primary Storage Form of Sulfur in Body:
    - Stored in amino acids as part of proteins, particularly methionine and cysteine.

Additional Learning Objectives

• Minerals Involved with Bone Health:
    - Key minerals include calcium, phosphorus, magnesium, and fluoride.

• Risk Factors for Osteoporosis:
    - Nonmodifiable:     - Female gender, older age (>50 yrs), small frame, family history of osteoporosis.   - Modifiable:
      - Sedentary lifestyle, poor diet (insufficient calcium and vitamin D), smoking, excess alcohol intake.

• Signs of Pre-eclampsia:
    - Characterized by headache, fatigue, protein in urine, and high blood pressure.

• Risk Factors for Pre-eclampsia:
      - Obesity, teenage pregnancy, history of pre-eclampsia, high blood pressure prior to pregnancy.

• Factors Affecting Mineral Absorption:
    - Dietary factors include phytates and oxalates which hinder absorption.   - Non-dietary factors include physiological needs (growth, pregnancy).

Iron

• Role of Iron in the Body:
    - Essential for oxygen transport in hemoglobin.
    - Total body iron stores: 2-4 g.

• Dietary Sources of Iron:
    - Heme Iron:
      - Found in animal products such as meat and seafood.
      - More readily absorbed.
    - Non-Heme Iron:
      - Found in plant-based sources.
      - Less bioavailable than heme iron.

• Absorption of Iron:
    - Enhancing factors: vitamin C and presence of heme iron.
    - Inhibiting factors: phytates, tannins, and calcium.

• Increased Iron Requirements:
    - Pregnant women (27 mg/day), women age 19-50 (18 mg/day), men and women over 50 (8 mg/day).

• Iron Toxicity:
    - Symptoms include abdominal pain, fatigue, may lead to liver damage.

Zinc

• Functions of Zinc:
    - Enzyme function, immune function, DNA synthesis, metabolism of macronutrients.

• Zinc Absorption:
    - Influenced by dietary components, particularly animal proteins.
    - High dietary phytates can decrease absorption.

• Zinc Deficiency Symptoms:
    - Include dwarfism, poor wound healing, hair loss, and loss of taste.

• Requirements:
    - RDA: 11 mg for men, 8 mg for women.

Copper

• Roles of Copper:
    - Involved in iron metabolism, antioxidant defense, and energy production.

• Copper Absorption:
    - 50% of dietary copper absorbed in small intestine.
    - Excess zinc can interfere with copper absorption.

• Requirements:
    - RDA is 900 µg per day.
    - UL is 10 mg per day.

Iodine

• Primary Role:
    - Essential for thyroid hormone production, regulating metabolic rate.

• Iodine Deficiency Effects:
    - Can lead to goiter and developmental issues such as cretinism in offspring.

• Dietary Sources:
    - Seafood, iodized salt, and plants from iodine-rich soil.

Selenium

• Primary Role:
    - Supports antioxidant defense via glutathione peroxidase.

• Requirements and Sources:
    - RDA: 55 µg per day.
    - Good sources include Brazil nuts and seafood.

Fluoride

• Role in the Body:
    - Strengthens tooth enamel and bones through hydroxyapatite crystals.

• Sources:
    - Fluoridated water, toothpaste.   - RDA is 4 mg for men, 3 mg for women.

Chromium

• Primary Function:
    - Enhances insulin function, aiding glucose uptake.

• Dietary Sources:
    - Brewer’s yeast, liver, nuts, whole grains.