FOOD20003 Lecture Notes - Lecture 27: Pyruvic Acid, Edema, Acetyl Group
28 Jun 2018
School
Department
Course
Professor
Vitamins
• Differ from carbs, proteins and fat in structure, function and food contents
o Not linked together and don’t yield energy
• Vitamins are similar to the energy yielding nutrients in that they are vital to life
• Organic molecules available from food
o Can be destroyed by exposure to light, oxidation, cooking and storage
o Should refrigerate fruits and vegetables, store cut fruits and vegetables
in airtight wrappers or closed containers, avoid high temperature and
long cooking times etc etc
• Deficiencies & excesses = detrimental for health
• Absorption, transport and storage
o Water-soluble vitamins (B group & Vitamin C) – required more
frequently
§ Absorbed directly into the blood
§ Circulate freely
§ Excreted in urine
o Fat-soluble vitamins (D, A, K, E) – required periodically
§ Absorbed into the lymph à blood
§ Require protein carriers
§ Stored in cells associated with fat
§ Less readily excreted
BACKGROUND DEFINITIONS
• Nutrients: chemical entities from foods that are vital to life
• Precursors (provitamins): consumed in an inactive form and become active
vitamins in the body
• Coenzymes: compounds that participate or assist in the action of enzymes
• Cofactors: inorganic compounds essential for enzyme activity
• Bio-accessibility: the accessibility of a nutrient for digestion and absorption
from foods
• Bio-availability: the rate and extent that a nutrient is absorbed and available
for body use
B-group Vitamins – SOME ARE COENZYMES
Vitamin
Function in the body
Food sources
Deficiency and
Toxicity
Thiamine
(B1)
• Involved in energy
metabolism as part of
the coenzyme
thiamine
pyrophosphate
• Required for the
conversion of:
Wholegrain,
fortified or
enriched grain
products
Moderate
amount in all
foods
Deficiency
• Enlarged heart
• Possible cardiac
failure
• Muscular
weakness
• Short-term
memory,
