Transcript Vitamins and Minerals

Vitamins
and
Minerals
Chapter 18
History of Vitamins
• Deficiency disease = a disease caused by a lack
of a specific nutrient (ex. Scurvy)
• Vitamins = complex organic substances vital to
life
– Have been known to scientists for a long
time, however they did not have the
equipment or knowledge needed to fully
understand them
– In the 1880s, Japanese navy’s surgeons
found that adding meat and vegetables to
the sailors’ diet seemed to prevent beriberi
= a disease of the nervous system that
causes partial paralysis, weakness, mental
confusion, and death.
– In 1915, vitamins were recognized as a
class of nutrients. Since then a dozen more
vitamins necessary to humans have been
identified, ending with vitamin B12 in 1948
DRI CHART
• http://fnic.nal.usda.gov/nal_display/in
dex.php?info_center=4&tax_level=1
&tax_subject=242
Function of Vitamins
• Vitamins perform specific functions in the
body by working with compounds called
enzymes
• Enzymes speed up reactions that would otherwise
proceed too slowly to sustain cell life
• Enzymes include two parts, a protein molecules and
a coenzyme
• If you don’t get enough of a certain vitamin, the
enzyme that needs that vitamin as its coenzyme
gradually slows its work (cell continue to function,
but less efficiently and the organs and tissues they
make up begin to die)
The Structure of Vitamins
• Vitamin molecules are single, selfcontained units
• Each vitamin has its own structure, but with
similar basic components
» Six-sided ring that includes carbon or
carbon and nitrogen atoms, joined by a
variety of single or double bonds
» Attached hydrogen atoms
» Attached hydrocarbons, which are
compounds of hydrogen and carbon atoms
(they include one carbon and up to three
hydrogen atoms)
Water-Soluble Vitamins
• Water-soluble vitamins = dissolve
in water
• Circulate freely in the blood and cell fluids
• Water-soluble vitamins are quickly
absorbed from the small intestine, and
excess amounts are excreted in urine
• Need to be consumed daily
• Total of 9 water-soluble vitamins
9 Water-Soluble Vitamins
• Thiamin or vit. B1
• Needed to metabolize carbohydrates
• Transmitting high-speed impulses in the nervous
system
• Found in peas, pork, peanuts and wheat germ
• Thiamin is easily destroyed by oxidation
• Riboflavin or vit. B2
• Important for growth
• Needed to metabolize protein and for tissue repair
• Found in both animal and vegetable foods including
broccoli, beef liver, asparagus and milk
• It helps form red blood cells and release energy
from glucose
• Also helps make another B vitamin, niacin
• Riboflavin is vulnerable to high pH and breaks down
under light
9 Water-Soluble Vitamins
• Niacin
• Crucial for the release of energy from carbohydrates, fats,
and protein
• Also needed for forming deoxyribonucleic acid, , better
known as DNA
• Very little is lost during food processing, because it resists
light, heat, oxidation, acids and bases
• Found in dry peas and beans, peanut butter, liver, chicken
and fish
• Vitamin C
• Nutrient is found in citrus fruits, broccoli, bell peppers,
potatoes, tomatoes and cabbage
• Helps prevent cell damage
• Promote iron absorption
• Helps the body heal wounds and resist infection
• Megadoses = excessively large amounts (people say
taking vitamin C in a large dose will cure a cold)
» Massive doses can cause kidney stones and diarrhea
• Vitamin C is stable in the presence of acids, but is
destroyed by oxidation, light, heat and bases
9 Water-Soluble Vitamins
• Vitamin B6
• Helps your body use carbohydrates and proteins
• Nervous system healthy and helps your body make
nonessential amino acids
• Found in poultry, whole grains, and legumes
• Vitamin B12
• You body can use carbohydrates, fats, and proteins
better
• Works with folate to help build red blood cells and
form genetic material
• Only animal products supply this vitamin
9 Water-Soluble Vitamins
• Folacin (folate or folic acid)
• Helps prevent birth defects of the brain and spinal
cord
• Pantothenic acid
• Helps the body release energy from carbohydrates,
fats, and proteins and helps produce cholesterol
• Promotes a healthy nervous system as well as
growth
• Found in meat, poultry, fish, eggs, legumes, milk
and whole-grain foods
• Biotin
• Helps your body use carbohydrates, fats, and
proteins
• Found in green, leafy vegetables, whole-grain
products, liver and egg yolks
Fat-Soluble Vitamins
• Fat-Soluble vitamins = dissolve in
lipids, rather than water
• They occur in the fats and oils of food, fatsoluble vitamins usually carried in the blood
in lipoproteins
• They are stored in the body until needed
– Advantage in preventing deficiency, but also
potentially dangerous in overdoses.
4 Fat-Soluble Vitamins
• Vitamin A (retinol)
• Found in animal products, such as liver,
butter, egg yolk and cheese
• Used mostly to maintain healthy skin and
mucous membranes which cells secrete
protective mucus in the walls of the
respiratory and digestive system
• Normal vision, development of bones
• The liver can store up to a year’s supply of
vitamin A
• Taking megadoses of vitamin A