NuH_Topic 5_rev

Topic 5: Micronutrients

Learning Objectives

  • Differentiate between vitamin categories:

    • Fat-soluble

    • Water-soluble

  • Differentiate between mineral categories:

    • Major (macro) minerals

    • Minor (micro) minerals

  • Identify food sources for vitamins and minerals.

  • Explain factors affecting mineral bioavailability.

  • Describe vitamin and mineral functions related to health.

  • State dietary recommendations for vitamins and minerals.

  • Discuss effects of deficiency and toxicity for each.

Key Concepts

  1. Vitamin Types:

    • Fat-soluble vs. Water-soluble

  2. Mineral Classification:

    • Major vs. Trace minerals

  3. Detailed Study of Each Vitamin and Mineral:

    • Function, Food sources, Bioavailability, Deficiency, Toxicity

    • No need to memorize RDA amounts.

Definition of Vitamins

  • Characteristics:

    • Organic compounds

    • Essential nutrients (body can't produce enough)

    • Non-energy yielding (no calories)

    • Required in small amounts to support vital functions.

General Facts

  • Nutritional Categories:

    • Organic (includes vitamins)

    • Inorganic (includes minerals, water)

Comparison with Other Nutrients

  • Vitamins vs. Carbohydrates, Proteins, Lipids:

    • Structure: Individual units (not linked subunits)

    • Function: Assist in energy release without being energy-yielding

    • Content: Very small amounts required daily.

Vitamin Qualifications

  • Must be unable to synthesize naturally.

  • Absence must lead to deficiency symptoms.

Vitamins in Foods

  • Found naturally in fresh foods; added to processed foods.

  • Inactive Forms (Provitamins):

    • Converted to active forms inside the body (e.g., beta-carotene to Vitamin A).

Addition of Vitamins to Foods

  1. Enrichment: Replace losses during processing.

  2. Fortification: Add vitamins that weren't originally present.

Bioavailability

  • Definition: Rate/extent nutrient is absorbed and used by the body.

  • Factors:

    • Digestion efficiency

    • Previous nutrient intake

    • Food combinations

    • Preparation methods

    • Nutrient source (natural vs. synthetic).

Toxicity

  • Fat-soluble vitamins (A & D) accumulate in the body and can cause harmful effects.

  • Established Tolerable Upper Intake Levels for safety.

Summary of Specific Vitamins

Fat-Soluble Vitamins

  • Vitamin A: Functions include vision, reproduction; sources are animal products and carotenoid-rich plants.

  • Vitamin D: Obtained from animal sources; crucial for calcium homeostasis; deficiency leads to rickets/osteomalacia.

  • Vitamin E: Functions as an antioxidant; found in oils, nuts; RDA for adults is 15mg.

  • Vitamin K: Important for blood clotting and bone health; mainly found in leafy greens.

Water-Soluble Vitamins

  • B Vitamins (B1, B2, B3, B5, B6, B7, B9, B12): Key roles in energy metabolism, red blood cell production.

    • Vitamin C: Antioxidant, aids collagen formation and iron absorption; found in fruits and vegetables.

Mineral Overview

Major (Macro): Required in amounts >100mg/day.

  • Example: Sodium, potassium, calcium. Minor (Micro): Required in amounts <100mg/day.

  • Example: Iron, zinc, iodine.

Summary of Key Minerals

  • Sodium: Essential for fluid balance, nerve transmission.

  • Calcium: Crucial for bone health; absorbed better with Vitamin D; sources include dairy.

  • Iron: Vital for oxygen transport; two forms—heme (animal) and non-heme (plant); deficiency leads to anemia.

  • Zinc: Supports immune function, wounds healing; found in protein-rich foods.

Deficiency and Toxicity for Major Micronutrients

  • Addresses depletion impacts and intake surplus risks for vitamins and minerals.