Water and Vitamins Lecture Notes

Water and Vitamins

We will cover water and vitamins in this lecture, with minerals to be discussed in Part 2.

Nutrient Classes

  • Macronutrients:
    • Carbs, lipids, proteins (previously covered).
    • Provide calories: 9 for fat, 4 for protein and carbs.
    • Alcohol: Provides calories but is not a nutrient (toxin/poison).
  • Micronutrients:
    • Vitamins (focus of today's lecture).
    • Minerals (to be discussed in part 2).
  • Water:
    • Often called a 'meganutrient'.

Vitamins

  • 13 essential vitamins.
  • Classified by solubility:
    • Fat-soluble (4):
      • Require fat for absorption and transport.
      • Vitamins A, D, E, and K.
    • Water-soluble (9):
      • Do not require fat for transport; move freely with water.
      • B vitamins and vitamin C.
  • Vitamins do not provide energy directly but assist in energy production.
  • Organic compounds: Contain two or more carbons.
  • Focus: Functions, necessity, and deficiency effects.

Minerals

  • Inorganic: Do not contain two or more carbons.
  • Homogeneous: Consist of the same unit (e.g., iron pill is only iron atoms).
  • Minerals do not provide energy.
  • Two categories:
    • Major minerals: Needed in amounts greater than 100 mg/day (e.g., sodium, potassium, calcium).
    • Trace minerals: Needed in amounts less than 100 mg/day (e.g., iron, zinc, copper).

Water - The Meganutrient

  • Functions:
    • Acts as a solvent: Allows for dissolution and chemical reactions.
      • Digestive system relies on a watery environment for reactions.
    • Lubricant: Keeps tissues moist (e.g., eyeballs).
    • Transportation: Moves nutrients throughout the body.
    • Regulation of body temperature:
      • Water retains heat.
      • Perspiration (sweat) releases heat from the body.
  • Categories of body water:
    • Intracellular: Fluid inside cells (two-thirds of body water).
    • Extracellular: Fluid outside cells.
      • Interstitial: Fluid between cells.
      • Intravascular: Blood plasma within the vascular system.
  • Blood volume maintenance:
    • Impacts blood pressure.
    • Adequate fluid maintains healthy blood pressure.
    • Sodium and water retention: Some individuals are sodium-sensitive, leading to increased water retention and elevated blood pressure.
  • Transportation: Nutrient movement throughout the body.
  • Lubrication: Keeps joints lubricated.
  • Temperature regulation: Heat retention and release via perspiration.
  • Waste removal:
    • Urine: Minimum of 500 mL/day to remove waste.
    • Fecal matter: Contains moisture to aid in waste elimination.

Water Sources and Intake

  • Recommended intake as a starting point:
    • 15 cups for men.
    • 11 cups for women.
  • Hydration check: Urine color.
    • Clear/pale yellow: Adequate hydration.
    • Yellow/orange: Dehydration.
  • Adaptation to water intake:
    • Initially, increased urination may occur with higher intake.
    • Body adapts over time to maintain balance.
  • Fluid sources:
    • Beverages (water, coffee, tea).
    • Food (fruits, vegetables).
  • Water content in foods:
    • Fruits and vegetables: High percentage of water.
    • Meats: Water content decreases with cooking.

Water Balance

  • Water in:
    • Fluids (beverages).
    • Food.
    • Metabolic water: Water produced by the body (e.g., during amino acid or glucose bonding in the mitochondria).
  • Water out:
    • Urine: Major way of fluid loss.
    • Skin: Perspiration.
    • Lung respiration: Exhalation.
    • Feces.

Dehydration Effects

  • Impacts ranked by percentage of body weight lost:
    • 1%:
      • Thirst (the signal that you're already a little dehydrated).
    • 2%:
      • Fatigue, loss of appetite, hemoconcentration (thicker blood).
    • 4%:
      • Confusion, flushed skin, sleeplessness.
    • 6%:
      • Significant symptoms manifest.
    • 8%:
      • Breathing difficulties (cyanosis), confusion, weakness.
    • 10%:
      • Delirium, circulation issues, potential kidney function loss.
    • Greater than 10%:
      • Severe hemoconcentration, brain and kidney shrinkage, heart strain.

Water Toxicity (Hyponatremia)

  • Consuming water in excess of kidney's elimination capacity.
  • Leads to increased blood volume and dilution of electrolytes.
  • Hyponatremia: Low sodium levels in the bloodstream.
    • Impacts muscle contraction, nerve conduction, and heart function.
  • Symptoms: Headaches, blurred vision, convulsions, brain swelling; potentially death.

Vitamins - An Overview

  • Essential nutrients: Body cannot produce them adequately; must be obtained through diet.
  • Organic compounds: Contain two or more carbon atoms.
  • Categories:
    • Fat-soluble: A, D, E, and K.
    • Water-soluble: B vitamins and vitamin C.

Vitamin History and Nomenclature

  • Vitamin A: First discovered, hence the designation.
  • B vitamins: Initially thought to be one vitamin; later differentiated by function and deficiency symptoms.
  • Vitamin naming gaps: Some vitamins were dropped from the essential list after being deemed non-essential.
  • Water-soluble vitamin names:
    • B1 (Thiamine), B2 (Riboflavin), etc. - need to know both common names and scientific nomenclature.

Obtaining Vitamins

  • Variety in diet ensures variability in micronutrient intake.
  • Different food groups provide different vitamins.

Preserving Vitamins

  • Vitamins are organic and can be damaged by:
    • Sunlight.
    • Oxygen.
    • UV light.

Digestion and Absorption

  • Water-soluble vitamins:
    • Dispersed equally throughout watery parts of the body.
    • Excess is filtered out by the kidneys.
    • Exceptions: Vitamins B6 and B12 (recycled or stored).
  • Fat-soluble vitamins:
    • Stored in fatty areas (adipose tissue).
    • Vitamin K: An exception; excess is easily eliminated.

Transportation of Vitamins

  • Fat-soluble:
    • Require fat for absorption and transport.
    • Transported via lipoproteins (chylomicrons and VLDL).
  • Water-soluble:
    • Move freely through watery parts of the body.
    • Dump directly into the bloodstream.
    • Tissues can easily absorb them.
  • Excess fat-soluble vitamins are stored, while excess water-soluble vitamins are eliminated.

Grains and Enrichment

  • Grains are a good source of B vitamins.
  • Whole grain composition:
    • Bran (outer layer): Protein, fiber, vitamins, and minerals.
    • Germ (inner part): Baby plant which contains healthy oils, protein, vitamins, and minerals.
    • Endosperm (majority of the grain inside): Starch.
  • Refining process: Removes the bran and germ, leaving mostly starch.
  • Enrichment process (law): Requires processed grains to have thiamine, riboflavin, niacin, folate (folic acid), and iron added back.
  • Eating whole grains is healthier than eating refined grains.
  • Ingredient lists will include enrichments if applied.

Vitamin Overview and Key Elements

For each vitamin, know the following:

  1. Name
  2. Function
  3. Deficiency symptoms (if any).
  4. Food source
  5. Toxicities (if any).

Vitamin A

  • Two forms:
    • Retinoids: Active form (from animal sources).
    • Carotenoids: Inactive form/precursor (from plant sources).
  • Functions:
    • Vision.
    • Cell differentiation (growth and development).
    • Immunity.
  • Deficiencies:
    • Growth issues.
    • Night blindness and total blindness (xerophthalmia).
    • Dry skin, hyperkeratosis (hardening of skin cells).
    • Impaired immune function.
  • Vision and Vitamin A:
    • Vitamin A works in two places in your eye, which causes different effects:
    • Retina:
      • Vitamin A is required in order to create rhodopsin (rhodopsin is opsin plus Vitamin A).
      • Light energy hits rhodopsin, which causes the rhodopsin to change shape.
      • In order for the light energy to pass a signal to your brain, your body must have the ability to form rhodopsin.
    • Cornea:
      • Vitamin A allows mucus cells to keep tissues moist.
      • When we lack Vitamin A, those mucus cells cannot help moisten our skin cells.
      • Skin becomes dry, rough, and cells will start to dry out and can become very hard and scaly.
      • Can cause the cells to become opaque, which means you cannot allow light to go through it.
  • Food Sources:
    • Animal sources: Liver, fatty tissue, fortified dairy products.
    • Plant sources (carotenoids): Orange or dark green vegetables and fruits high in beta-carotene (carrots, apricots, mangoes).
      • The body converts them to the active form, retinoids, when needed.
  • Toxicities:
    • Vitamin A has a narrow range before toxic effects can occur (about three times the RDA before reaching upper limits).
    • Liver damage, aches and pains, headaches, nausea.
    • Birth defects and miscarriages (important concern for women of childbearing age; e.g., Accutane).

Vitamin D

  • Cholecalciferol: Active form (D3).
  • Ergocalciferol: Inactive form (D2), needs to be activated.
  • Functions:
    • Required for calcium and phosphorus absorption for bone health.
    • Immune system support, growth and development.
    • Potential role in cancer prevention.
  • Deficiency symptoms:
    • Rickets (in children): Bowed legs due to insufficient bone mineralization.
    • Osteomalacia (in adults): Porous bones, fractures (not legs bowing outward).
  • Food sources:
    • Fatty fish and fish oils, fortified dairy products, mushrooms, fortified cereals.
    • Limited natural food sources; body can produce vitamin D from cholesterol and sunlight exposure.
  • Toxicities:
    • Calcification of soft tissues (arteries, veins, muscle tissue, organs).
    • Occurs with excess calcium and vitamin D (normal levels of vitamin D can result in excreting excess calcium via urine).
    • Vitamin D enables mineralization of bones/tissues by facilitating calcium/phosphorus entry.

Vitamin E

  • Family of compounds: Tocopherols (alpha, beta, gamma, delta).
  • Functions:
    • Fat-soluble antioxidant, prevents oxidative damage to tissues.
    • Protects cell membranes from free radicals.
    • Vitamin C helps regenerate (re-traps) vitamin E, allowing it to continue as an antioxidant.
  • Deficiency symptoms:
    • Nerve degeneration and damage.
    • Hemolysis of red blood cells (splitting open of your red blood cells).
  • Food sources:
    • Plant oils, nuts, and seeds.
  • Toxicities:
    • Unusual, but possible with supplementation.
    • Inhibits vitamin K (potential increased hemorrhaging).

Vitamin K

  • Phylloquinone.
  • Functions:
    • Clotting cascade (production of fibrin to stop bleeding).
    • Bone formation.
  • Deficiency symptoms:
    • Hemorrhaging.
  • Newborns: Given vitamin K shot as they lack the ability to produce it.
  • Sources:
    • Dark green leafy vegetables (Brussels sprouts, broccoli, asparagus, kale).
    • Intestinal bacteria produce some vitamin K (10%).
  • Toxicities:
    • Rare due to efficient elimination.
    • No established upper limit.