The document discusses vitamins, including water soluble and fat soluble vitamins. It covers vitamin functions such as acting as coenzymes in energy production and as antioxidants. The document discusses vitamin needs, bioavailability, sources of various vitamins like folate, and deficiencies that can arise from a lack of vitamins. It is a chapter from a textbook about vitamins that provides information on the roles and functions of different vitamins.

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Chapter 7: Vitamins
Copyright © 2012 John Wiley & Sons, Inc. All rights reserved. © 2012 John Wiley & Sons, Inc. All rights reserved.
Student learning outcomes: At the end of this chapter, you should be able to:
Water-soluble and fat-soluble vitamins
Describe the role of vitamins in health and disease
Food sources
© 2012 John Wiley & Sons, Inc. All rights reserved.
Vitamins
Vitamins
Water soluble
Fat soluble
Riboflavin
Thiamin
Niacin
B Vitamins
Vitamin C
Vitamin A
Vitamin D
Vitamin E
Biotin
Pantothenic acid
Vitamin K
Folate
Vitamin B12
Vitamin B6
© 2012 John Wiley & Sons, Inc. All rights reserved.
Tips for preserving vitamins
© 2012 John Wiley & Sons, Inc. All rights reserved.
Vitamin bioavailability
Affected by:
Absorption
Fat-soluble vitamins: need dietary fat
Transport in blood
Water-soluble vitamins
Fat-soluble vitamins
© 2012 John Wiley & Sons, Inc. All rights reserved.
Vitamin bioavailability

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© 2012 John Wiley & Sons, Inc. All rights reserved.
Vitamin functions
© 2012 John Wiley & Sons, Inc. All rights reserved.
Coenzymes
Bind enzymes to promote their activity
Carriers of electrons, atoms, or chemical groups that participate in the reactions
Examples: B vitamins
How it works: 7.1 Vitamins acting as coenzymes
© 2012 John Wiley & Sons, Inc. All rights reserved.
Coenzymes
© 2012 John Wiley & Sons, Inc. All rights reserved.
B vitamins = coenzymes in energy production
© 2012 John Wiley & Sons, Inc. All rights reserved.
Free radicals & antioxidants
Oxidative damageto cell membranes, DNA, structures, etc
Examples: Free radicals –generated by the body or from exposure to the environment
Antioxidants: neutralize reactive oxygen molecules
Examples: Vitamin C, vitamin E
© 2012 John Wiley & Sons, Inc. All rights reserved.
Free radicals & antioxidants

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© 2012 John Wiley & Sons, Inc. All rights reserved.
Meeting vitamin needs
Review:
DRIs include RDA, AI, and UL
Which vits are required on food labels as %DV?
© 2012 John Wiley & Sons, Inc. All rights reserved.
David’s need for a vitamin is 220mg each day. The bioavailability of this vitamin is 40%. This means that Brian needs to consume _____ milligrams each day for this vitamin to meet his needs.
0.40 x 220 =
88mg
88mg + 220mg =
308mg
© 2012 John Wiley & Sons, Inc. All rights reserved.
Water-soluble vitamins
B vitamins: involved in converting the energy in carbohydrate, fat, and protein into ATP
Vitamin C: needed to make connective tissue and as an antioxidant
Not stored -need to be consumed regularly
Excreted in urine
Niacin
•Niacin needs can be met through the synthesis of niacin from tryptophan.
•RDA is expressed as niacin equivalents (NEs)
•One NE: 1 mg of niacin or 60 mg of tryptophan (the amount needed to make 1 mg of niacin)
© 2012 John Wiley & Sons, Inc. All rights reserved.
© 2012 John Wiley & Sons, Inc. All rights reserved.
Folate (folic acid) functions
Folate coenzymesneeded for DNA synthesis (especially needed in rapidly-dividing tissues)
Neural tube formation
Prevent homocysteine levels from rising to prevent heart disease © 2012 John Wiley & Sons, Inc. All rights reserved.
Folate (folic acid) functions

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© 2012 John Wiley & Sons, Inc. All rights reserved.
Folate (folic acid) functions
© 2012 John Wiley & Sons, Inc. All rights reserved.
Folate & vitamin B12
© 2012 John Wiley & Sons, Inc. All rights reserved.
Folate (folic acid)
Sources: enriched grains, leafy greens, asparagus, legumes, nuts, oranges, liver, yeast
Deficiency: neural tube defects including spina bifida, macrocytic or megaloblastic anemia, poor growth, nerve development and function problems
Excess: concerns that excess will prevent folate- deficiency symptoms and mask B12deficiencies
Why?
© 2012 John Wiley & Sons, Inc. All rights reserved.
Folate (folic acid) sources