Micronutrients: Vitamins and Minerals – Structure, Functions, and Classification

Micronutrients: Vitamins and Minerals

Overview of Micronutrients

Micronutrients are essential nutrients required by the body in small amounts for proper physiological function. Unlike macronutrients, micronutrients do not provide energy but are crucial for metabolic processes, growth, and development.

• Vitamins and minerals are the two main classes of micronutrients.

• They are best obtained through a varied diet.

• Supplementation may be necessary in special cases.

Vitamins

Definition and Composition

Vitamins are organic compounds (contain carbon) that are required in small amounts for various biochemical functions.

• Examples: Vitamin C, Vitamin B12, Vitamin K

• Structure: Complex molecules, often with ring structures (see example diagrams).

Functions of Vitamins

• Coenzymes: Many vitamins work with enzymes to regulate reactions (e.g., vitamin B6).

• Antioxidants: Some vitamins (e.g., vitamin C, vitamin A) help protect cells from oxidative damage.

• Regulation: Vitamins are involved in processes such as vision (vitamin A), blood clotting (vitamin K), and bone health (vitamin D).

Classification of Vitamins

• Water-soluble: Includes vitamin C and B-complex vitamins. Not stored in the body; excess is removed in urine.

• Fat-soluble: Includes vitamins A, D, E, and K. Stored in body fat; excess may be toxic.

Key Points

• Vitamins are organic and essential for health.

• Do not provide energy.

Minerals

Definition and Composition

Minerals are inorganic elements (do not contain carbon) that are required for various physiological functions.

• Examples: Calcium, Iron, Sodium, Potassium

• Represented on the periodic table (see diagram).

Functions of Minerals

• Structural: Major component of bones and teeth (e.g., calcium, phosphorus).

• Regulatory: Maintain fluid balance (e.g., sodium, potassium), nerve transmission, muscle contraction.

• Cofactors: Work with enzymes to regulate metabolism (e.g., magnesium, zinc).

Classification of Minerals

• Major minerals: Required in quantities greater than 100 mg/day (e.g., calcium, sodium, potassium).

• Trace minerals: Required in quantities less than 100 mg/day (e.g., iron, zinc, copper).

Key Points

• Minerals are inorganic and essential for health.

• Do not provide energy.

Comparison: Vitamins vs. Minerals

Similarities and Differences

Feature	Vitamins	Minerals
Composition	Organic compounds	Inorganic elements
Classification	Water-soluble & Fat-soluble	Major & Trace
Function	Coenzymes, antioxidants, regulation	Structural, regulatory, cofactors
Energy Provision	Do not provide energy	Do not provide energy
Dietary Source	Varied diet, sometimes supplements	Varied diet, sometimes supplements

Venn Diagram Summary

• Vitamins: Organic, classified as water- or fat-soluble, work with enzymes, do not provide energy.

• Minerals: Inorganic, classified as major or trace, make up bone/teeth, do not provide energy.

• Both: Essential, do not provide energy, required in small amounts, regulate body functions.

Examples and Applications

• Vitamin C: Water-soluble vitamin, functions as an antioxidant and coenzyme in collagen synthesis.

• Calcium: Major mineral, essential for bone structure and muscle contraction.

• Iron: Trace mineral, required for oxygen transport in hemoglobin.

Key Equations and Concepts

• Recommended Dietary Allowance (RDA): The average daily intake level sufficient to meet the nutrient requirements of nearly all (97–98%) healthy individuals.

$\text{RDA}_{\text{nutrient}} = \text{Average daily intake sufficient for nearly all healthy individuals}$

Additional Info

• Micronutrient deficiencies can lead to specific diseases (e.g., scurvy from lack of vitamin C, anemia from lack of iron).

• Excess intake of fat-soluble vitamins or certain minerals can be toxic.