💧 Lecture 3: Part 2 - Water-Soluble Vitamins + Minerals

B Vitamins – Water Soluble

Functions
  • Act as coenzymes for cell metabolism or as precursors to coenzymes

B₁ – Thiamine
  • Deficiency: Beriberi → edema and heart problems

B₂ – Riboflavin
  • Deficiency: Ariboflavinosis → skin disorders and edema

B₃ Complex – Niacin
  • Includes niacin (nicotinic acid) and nicotinamide
  • Can be synthesized from tryptophan, but with poor efficiency
  • Deficiency: Pellagra → skin disorders, dementia, and diarrhea

B₅ – Pantothenic Acid
  • Precursor for coenzyme A
  • Coenzyme A is a critical component for the TCAC
  • Deficiency: Rare

B Vitamins – B₆ and B₇

Functions
  • Act as coenzymes for cell metabolism or as precursors to coenzymes

B₆ Complex – Pyridoxine and Pyridoxamine
  • Involved in amino acid metabolism
  • Carnivores have an elevated requirement
  • Deficiency: Dermatitis → skin inflammation

B₇ – Biotin
  • Can be synthesized by gut bacteria
  • May not be essential for ruminants
  • Deficiency: Anemia and hair loss

B Vitamins – B₉ and B₁₂

Functions
  • Act as coenzymes for cell metabolism or as precursors to coenzymes

B₉ – Folate (Folic Acid)
  • Can be synthesized by gut bacteria
  • May not be essential for ruminants
  • Deficiency: Folate deficiency anemia

B₁₂ – Cobalamin
  • Synthesized by gut bacteria
  • All animals depend on microbially synthesized B₁₂
  • Deficiency: Severe and irreversible brain and CNS damage

Vitamin C

Functions
  • Antioxidant
  • Collagen formation
  • Hormone synthesis
  • Iron absorption

Deficiency
  • Scurvy
    • Skin disorders
    • Impaired wound healing
    • Increased risk of hemorrhage

Vitamin C – Essentiality

Nonessential
  • Reptiles
  • Amphibians
  • Some birds, mostly non-passerine
  • Most mammals

Essential
  • Bats
  • Many passerine birds → “perching” birds
  • Osteichthyes → “bony” fish
  • Guinea pigs and capybara

Vitamin C – Synthesis

Starting Materials
  • Glucose
  • Galactose

Vitamin C Synthesis Pathway
  • Glucose or galactose → D-glucuronic acid
  • D-glucuronic acid → L-gulonic acid
  • L-gulonic acid → L-gulono-γ-lactone
  • L-gulono-γ-lactone oxidase converts L-gulono-γ-lactone → L-2-oxogulono-γ-lactone
  • L-2-oxogulono-γ-lactone → ascorbic acid
  • Final step occurs spontaneously

Key Point
  • Ascorbic acid = Vitamin C

Vitamin C – Synthesis

Starting Materials

  • Glucose
  • Galactose

Vitamin C Synthesis Pathway

  • Glucose or galactose → D-glucuronic acid
  • D-glucuronic acid → L-gulonic acid
  • L-gulonic acid → L-gulono-γ-lactone
  • L-gulono-γ-lactone oxidase converts L-gulono-γ-lactone → L-2-oxogulono-γ-lactone
  • L-2-oxogulono-γ-lactone → ascorbic acid
  • Final step occurs spontaneously

Key Point

  • Ascorbic acid = Vitamin C
  • Humans lack L-gulono-γ-lactone oxidase, so we cannot synthesize Vitamin C and must obtain it from the diet.

Choline and Inositol – Water-Soluble “Vitamins”

Functions
  • Choline and inositol are involved in the structure of cellular membranes
  • Found in phosphatidylcholine and phosphatidyl-inositol

Choline
  • Involved in lipid transport and metabolism
  • Part of phosphatidylcholine

Inositol
  • Involved in neurotransmitter synthesis
  • Part of phosphatidyl-inositol

Key Point
  • Both choline and inositol are water-soluble “vitamins” and contribute to cell membrane structure

Choline – “Vitamin B4”

Essentiality
  • Conditionally essential → required in the diet under certain conditions

Synthesis
  • Synthesized during methionine metabolism

Inositol – “Vitamin B8”

Essentiality
  • Non-essential

Synthesis
  • Synthesized from glucose

Choline and Inositol – Essentiality

Choline – “Vitamin B4”
  • Conditionally essential
  • Synthesized from methionine

Inositol – “Vitamin B8”
  • Non-essential
  • Synthesized from glucose

Synthesis During Certain Life Stages
  • Synthesis is slow during growth and geriatric phases
  • May be insufficient during these stages

Minerals

Definition
  • Inorganic compounds → no carbon skeleton
  • All are essential → cannot be synthesized by any animal or plant

Sources
  • Must be obtained through the diet
  • Plants → accumulate minerals from the soil
  • Animals → accumulate minerals from eating plants or animals
  • Free water → can provide minerals

Mineral Availability
  • The environment has a large influence on mineral availability

Mineral Classification

Macrominerals
  • Required in amounts > 5 g
  • Sodium
  • Potassium
  • Chloride
  • Sulfur
  • Calcium
  • Phosphorus
  • Magnesium

MAIN Micro/Trace Minerals
  • Required in amounts < 5 g
  • Iron
  • Zinc
  • Cobalt (ruminants only)
  • Selenium
  • Iodine
  • Copper
  • Manganese
  • Chromium
  • Molybdenum
  • Fluorine

OTHER Trace Minerals
  • More than a dozen trace minerals can be found in the body
  • Arsenic
  • Nickel
  • Silicon
  • Boron

Functions of Minerals

1. Skeletal Structure
  • Minerals are constituents of skeletal structures
  • Calcium + phosphorus → found in bone

2. Osmotic Pressure
  • Minerals help maintain osmotic pressure → movement of water between body fluids
  • Sodium → mainly in extracellular fluid
  • Potassium → mainly in intracellular fluid

3. Acid/Base Balance
  • Minerals help regulate acid/base balance → maintain proper pH
  • Chloride → involved in acid/base regulation in the kidneys

4. Components of Enzymes
  • Minerals can be components of enzymes or other molecules needed for enzyme function
  • Cobalt → part of vitamin B₁₂

5. Activators of Enzymes
  • Minerals can activate enzymes
  • Calcium → activates CaMKII

6. Components of Biological Units
  • Minerals can be components of important biological molecules
  • Iron → component of hemoglobin
  • Iodine → component of thyroxine

Organic vs Inorganic Minerals

Nutritionally Organic Minerals
  • Minerals that are chelated (bound) to a carbon-containing compound
  • Example: amino acid
  • Generally more bioavailable → easier for the animal to absorb and use
  • Example: copper lysinate

Nutritionally Inorganic Minerals
  • Elements or molecules without carbon
  • Generally less bioavailable
  • Example: copper sulphate

Calcium and Phosphorus

Calcium (Ca)
  • 1st most abundant mineral in the body
  • Main role → formation of bone, teeth, antler, eggshell, and milk
  • Found in milk, eggs, bone, and vegetation

Phosphorus (P)
  • 2nd most abundant mineral in the body
  • Main role → formation of bone, ATP, and phospholipids
  • Found in animal tissue, milk, grains, and vegetation

Phosphorus

Main Role
  • Formation of bone, ATP, and phospholipids

Sources
  • Found in animal tissue, milk, grains, and vegetation
  • In plants, much of the phosphorus (P) may be present as phytate

Phytate
  • Phytate = inositol hexaphosphate (InsP₆)
  • A form of phosphorus found in plants

Calcium and Phosphorus – Deficiency and Requirement

Deficiency
  • Rickets → occurs in young animals
  • Osteomalacia → metabolic bone disease

Requirement
  • Considered as a ratio
  • Ca:P should be 1:1 – 2:1

Minerals – Electrolytes

Electrolytes
  • Ca²⁺, P (PO₄³⁻), Mg²⁺, Cl⁻, Na⁺, K⁺
  • Help maintain intracellular and extracellular fluid balance
  • Create osmotic gradients → regulate body fluid status and movement

Cations
  • Positively (+) charged ions
  • Ca²⁺, Mg²⁺, Na⁺, K⁺
  • Memory tip → “Pawsitively charged = Cations”

Minerals – Electrolytes

Electrolytes
  • Ca²⁺, P (PO₄³⁻), Mg²⁺, Cl⁻, Na⁺, K⁺
  • Help maintain intracellular and extracellular fluid balance
  • Create osmotic gradients → regulate body fluid status and movement

Anions
  • Negatively (-) charged ions
  • P (PO₄³⁻) and Cl⁻
  • Memory tip → “Negative = Anions”

Minerals – Electrolyte Imbalance

Electrolytes
  • Ca²⁺, P (PO₄³⁻), Mg²⁺, Cl⁻, Na⁺, K⁺

Electrolyte Imbalance
  • Chronic imbalance → cardiovascular issues
  • Acute imbalance → fatigue and emesis (vomiting)

Trace Minerals – Cobalt

Cobalt (Co)
  • Only essential mineral for ruminants → foregut-fermenting species
  • Also essential for some monogastric hindgut-fermenting species

Function
  • Required for the synthesis of vitamin B₁₂ (cobalamin)