Vitamins: Properties, Absorption, and Classification

Water-Soluble Vitamins

Water-soluble vitamins are a group of micronutrients essential for various metabolic processes. Their absorption, storage, and excretion differ significantly from fat-soluble vitamins.

• Absorption: Water-soluble vitamins are absorbed directly into the portal blood without requiring fat or chylomicron formation. Most are not stored extensively in the body (except vitamin B12), and excess is typically excreted in urine.

• Storage: Minimal storage in tissues; regular dietary intake is necessary.

• Examples: Vitamin C, B-complex vitamins (e.g., B1, B2, B3, B6, B12, folate).

Fat-Soluble Vitamins

Fat-soluble vitamins require dietary fat for absorption and are stored in body tissues for longer periods.

• Absorption: Depend on bile salts to form micelles, then transported in chylomicrons via the lymphatic system before entering the bloodstream.

• Storage: Extensively stored in adipose tissue and the liver; excess intake can lead to toxicity.

• Examples: Vitamins A, D, E, K.

True Vitamins vs. Vitamin-Like Nutrients

True vitamins are organic micronutrients that must be obtained from the diet because the body cannot synthesize them in sufficient quantities. Vitamin-like nutrients may be synthesized endogenously or required only under special conditions.

• True vitamins: Required from the diet under all circumstances.

• Vitamin-like nutrients: May be synthesized by the body or required only in certain situations (e.g., choline).

Vitamins as Micronutrients

Vitamins are defined as organic compounds required in small amounts for normal metabolic processes, often functioning as enzyme cofactors.

• Role: Facilitate biochemical reactions, support growth, and maintain health.

• Requirement: Needed in microgram to milligram quantities.

Minerals: Classification, Functions, and Examples

Minerals vs. Vitamins

Minerals are inorganic elements required for various physiological functions, while vitamins are organic compounds.

• Minerals: Inorganic, do not contain carbon, required for structural and regulatory roles.

• Vitamins: Organic, carbon-containing, function mainly as enzyme cofactors.

Major Minerals

Major minerals are required in larger amounts and play key roles in body structure and function.

• Calcium: Essential for bone and teeth structure, muscle contraction, nerve signaling, and blood pressure regulation.

• Phosphorus: Component of bones, teeth, and cellular energy systems (ATP).

• Sodium: Main extracellular cation, regulates fluid balance and nerve transmission.

• Potassium: Main intracellular cation, crucial for muscle function and heart rhythm.

• Chloride: Major extracellular anion, component of stomach acid (HCl), maintains fluid balance.

• Magnesium: Cofactor for many enzymes, involved in energy production and bone health.

• Sulfur: Part of amino acids and vitamins, stabilizes protein structure.

Trace Minerals

Trace minerals are required in minute amounts but are vital for health.

• Iron: Central atom in hemoglobin and myoglobin, binds oxygen for transport and storage.

• Zinc, Selenium, Manganese, Chromium, Molybdenum: Function as enzyme cofactors, regulate gene expression, and support immune function.

• Fluoride: Incorporates into tooth enamel, strengthens mineralization, inhibits bacterial acid production, and reduces dental caries.

• Iodine: Essential for thyroid hormone synthesis.

• Copper: Cofactor for enzymes involved in iron metabolism and connective tissue formation.

Bone Health: Cortical vs. Trabecular Bone

Bone tissue is classified into cortical (compact) and trabecular (spongy) types, each with distinct structure and function.

• Cortical bone: Dense outer shell, provides structural rigidity, slowly remodels over time.

• Trabecular bone: Porous inner scaffold, contains marrow, metabolically active, remodels more rapidly.

Water: Distribution and Importance

Body Water Content

Water is the most abundant component of the human body, essential for physiological processes.

• Typical range: Approximately 50–70% of body mass in healthy adults.

• Functions: Solvent for biochemical reactions, temperature regulation, nutrient transport, waste removal.

Alcohol: Effects, Metabolism, and Health Implications

Alcohol as a CNS Depressant

Ethanol acts as a central nervous system depressant by reducing neuronal signaling speed and efficiency, leading to slowed cognition and reflexes.

Alcohol and Pregnancy (Fetal Alcohol Spectrum Disorders)

Alcohol exposure during pregnancy can cause FASD due to the inability of the developing fetus to metabolize alcohol, resulting in structural and neurological damage.

Alcohol Production and Metabolism

• Production: Ethanol is produced when yeast ferments carbohydrates, generating ethanol as a metabolic byproduct.

• Blood Alcohol Content (BAC): BAC is the proportion of ethanol in arterial blood, expressed as a percentage, correlating with intoxication and physiological effects.

Blood Pressure: Hypertension and Minerals

Systolic and Diastolic Blood Pressure

Blood pressure is measured as systolic (during heart contraction) and diastolic (during relaxation). Hypertension is diagnosed at values above 140/90 mmHg.

• Normal target: <120/80 mmHg

• Hypertension: >130/80 mmHg

Summary Table: Vitamins vs. Minerals

Key Equations

• Blood Alcohol Content (BAC):

• Body Water Percentage:

Additional info:

• Some context and definitions were expanded for clarity and completeness.

• Table and equations were inferred and formatted for academic study purposes.