13 – Vitamins and Minerals Intro

Question 1

Do animals need vitamin/mineral supplements?

Answer 1

• NO: when commercial feeds usually nutritionally complete
• YES: when producer or owner is making their own diets

Question 2

Ca and P are added separately in addition to the vitamin/mineral premix

Answer 2

• *need to pay attention to them
  o Most raw diets for dogs are shown to be deficient in these and/or vitamin D
  o Increased incidence of unusual fractures in large breed puppies fed raw diets

Question 3

How important is vitamin/mineral nutrition?

Answer 3

• Critical to growth and health of animals
• Grazing animals are of particular concern
• *important to know what role vitamins and minerals play in animal growth and physiology

Question 4

Some examples of water soluble vitamins

Answer 4

• Thiamin
• Riboflavin
• Niacin
• Pantothenate
• Biotin
• Folic acid
• Vit B12
• Pyridoxine
• (*all are B vitamins)
• Vit C

Question 5

Some examples of fat soluble vitamins

Answer 5

• Vit A
• Vit D
• Vit E
• Vit K

Question 6

Absorption of microminerals

Answer 6

• Most microminerals form salts and other compounds which are relatively INSOLUBLE (I and Se are exceptions)
• NOT readily absorbed
• Minerals often require carrier proteins
  o Synthesis of these proteins is important in regulation of mineral metabolism

Question 7

Chelation

Answer 7

• Metal ions are reactive
• Must be chelated to prevent oxidation in the body
  o How many are given (ex. iron as a heme-protein)
• Metals form complexes with a well-defined number of organic LIGANDS

Question 8

Ligands (chelation)

Answer 8

• Can consist of neutral or anionic chemical groups
• Proteins and AA are common ligands

Question 9

Transport of trace elements in blood

Answer 9

• Trans-cobalamin II: *Cobalt
• Transferrin: Cr, *Fe, Mn, Zn (Mo, Se)
• Albumin: Cu, Zn
• AAs: Cu, Fe
• Globulins: *Mo
• *selenium: transported as a replacement for sulfur (transport as Se-methionine)

Question 10

Storage of minerals

Answer 10

• Most have significant storage so deficiencies will NOT occur unless absent from diet from weeks to years (exception Na and K)
• Macrominerals stored in bones (Ca, P, Mg)
• Microminerals stored in liver often associated with specific storage proteins (Fe, Cu, Zn, Se, Cr, and others)

Question 11

Vitamins

Answer 11

• Organic nutrients required in small quantities for a variety of biochemical functions
• Generally cannot be synthesized by the body and must be supplied in DIET
• (Vitamin theory of disease to account for scurvy, rickets, pellagra)

Question 12

Water soluble vitamins

Answer 12

• All B vitamins are absorbed passively at high levels in the gut AND by sodium-dependent active transport at low levels in the gut (exception Vit B12)
• Excesses are excreted in urine
• Toxicity rarely a problem (but possible)
• Storage is limited (apart from Vit B12) and must be provided regularly
• *and Vit C

Question 13

Water soluble vitamins: monogastrics vs. ruminants

Answer 13

• Rumen bacteria can synthesize B vitamins and Vit K
  o Production exceeds ruminant requirements
• *monogastrics do have some production of B vitamins in ceca and hindgut but absorption in hindgut is LIMITED

Question 14

Water soluble vitamins: horses

Answer 14

• Normal horse can produce most of B-complex in adequate amounts in its intestinal tract
• Research failed to show a response to supplemental B-vitamins with normal horses fed good quality feed
• Young growing foals and horses under stress may benefit from B vitamin supplements

Question 15

Rabbits and coprophagy (psuedorumination)

Answer 15

• Cecotrophes are consumed directly from the anus
• Fermentation in cecum and practice of coprophagy provides necessary amounts of most B vitamins and Vit K
• *coprophagy is also practiced by dogs, rats, gorillas

Question 16

Fat soluble vitamins

Answer 16

• Vit A, D, E, K (all are isoprene derviatives)
• Non-polar hydrophobic molecules
• All handled by GI system in same way as dietary fat
• After absorption fat-soluble vitamins transport to liver in chylomicrons
• Can be stored (unlike water soluble vitamins)
  o Vit A, D K: liver
  o Vit E: adipose tissue
  o *toxicity can occur (Vit A and D)

Question 17

Fat soluble vitamins excretion

Answer 17

• NOT in urine
• Appear in bile and excreted in feces

Question 18

Vit D: a vitamin?

Answer 18

• Is not a true vitamin
• Hormone involved in regulation of calcium/phosphorus metabolism

Question 19

What are the 5 groupings of vitamins and minerals?

Answer 19

1. Electrolytes: Na, K
2. Bones: Ca, P, Mg, Vit D, Vit K
3. Energy releasing vitamins: thiamin, riboflavin, niacin, pantothenate, biotin
4. Hematopoetic: folate, B12, Fe, Cu
5. Antioxidant: Vit E, Vit C, Se

Question 20

Electrolytes

Answer 20

• Maintain osmotic and electrolytic environment in body fluids (maintain PROTEIN FUNCTION)
• Maintain Na/K gradient between intracellular and extracellular environment
  o Nerve and muscle function
  o Transport of molecules across cell membrane
  o (1/3 ATP in animal goes to Na/K ATPase)
• *concentrations are maintained at DEFINED levels in intra and extracellular fluids

Question 21

Electrolyte deficiency symptoms: Na

Answer 21

• Lethargy
• Loss of appetite
• Muscle weakness
• Respiratory depression
• Cardiac arrest

Question 22

Electrolyte deficiency symptoms: K

Answer 22

• Elevated blood pressure
• Muscle weakness
• Respiratory depression
• Cardiac arrest

Question 23

Electrolyte toxicity symptoms: Na

Answer 23

• Dehydration
• Seizure
• Coma

Question 24

Electrolyte toxicity symptoms: K

Answer 24

• Cardiac arrhythmia and death