1. Vitamins
Chapter 6

2. Learning Objectives
State four general characteristics of vitamins, and explain how water-soluble and fat-soluble vitamins are different.
Identify which vitamin is deficient in the American diet and two vitamins that are toxic when taken in excess.
Identify functions and food sources of each vitamin presented.
List benefits of eating fruits and vegetables.
Discuss the use of fruits and vegetables on the menu, and describe ways to conserve vitamins when handling and cooking fruits and vegetables.
Define phytochemicals and give examples of foods in which they are found.

3. Basics of Vitamins
Vitamins = organic substances that carry out processes in the body that are vital to health
Very small amounts are needed
and only small amounts are in foods (micronutrients)
Most vitamins are obtained by eating foods
some are made by intestinal bacteria (K) and one is made in the skin in sunlight (D).
There is no perfect food with all the vitamins you need in just the right amounts.
Its important to eat a variety of foods
Vitamins do contain kcalories.

4. Basics of Vitamins Some vitamins in foods are precursors.
They change into a usable form in the body
Some act as antioxidants
Combine with oxygen so it cannot destroy important substances in the body (cells, tissues, etc)
Combat free radicals, unstable compounds that react negatively with other substances in the body (mutation)

5. Two Categories of Vitamins
Fat-soluble
Occur in foods containing fats
Stored in the body in fat cells
Not readily excreted
Include vitamins A, D, E, and K
Transported around the body by lipoproteins
Water-soluble
Includes vitamin C and B-complex vitamins
B vitamins work in every cell where they function as part of coenzymes
A coenzyme combines with an enzyme to allow the enzyme to do its job
Must take daily because excess is excreted through water loss (except B6 and B12)

6. Fat-Soluble Vitamins
Vitamin A
Vitamin D
Vitamin E
Vitamin K

7. Vitamin A
Functions:
Maintains the health of the eye and vision (prevents night blindness)
Promote healthy skin and surface linings of the lungs, GI tract, etc.
Supports reproduction, growth, and development
Food Sources:
Milk and eggs
Many red, orange, or yellow fruits and vegetables
Animal proteins
Dark green veggies

8. Vitamin A Carotenoids—
can be converted to Retinal (the usable form of vitamin A)
beta carotene
Retinoids—
The usable form of Vitamin A in the body
Most abundant in liver

9. Vitamin D Functions: Functions as a hormone
maintains normal blood levels of calcium and phosphorus by enhancing their absorption into the body
Normal blood levels of calcium and phosphorus are needed to make and maintain strong bones.
When ultraviolet rays shine on your skin, you make a precursor of vitamin D

10. Vitamin D Very few foods contain vitamin D except for fatty fish.
All milk is fortified with vitamin D.
Most cereals are fortified.
Several months of D can be stored in the body, so it is helpful during winter months when sun is not as strong.
Vitamin D is the most toxic of all vitamins when taken in excess.
Can cause calcium build up in the heart, blood vessels and kidneys which can result in death

11. Vitamin D
A majority of adults and many children in the United States do not meet the RDA.
As you get older, the amount of vitamin D your body makes from sun exposure decreases by more than 50 percent.
Vitamin D deficiency in children can cause rickets; in adults can cause osteomalacia.
Vitamin D deficiency can contribute to osteoporosis (fragile bones likely to break)— typically seen in older women.

12. Vitamin E
Functions:
Powerful antioxidant against cell membrane deterioration
Can be used to deter the appearance of scars
Is thought to prevent or delay the development of chronic heart disease
Widely distributed in plant foods, oils, nuts, seeds and whole grains

13. Vitamin K
Made in the intestines by naturally occurring bacteria (meets about half your needs)
Acts as a hormone
Vital in blood clotting
Good sources in food:
leafy greens (kale, collards, spinach, broccoli, scallions, cabbage)
Antibiotics destroy all bacteria in the body including the naturally occurring bacteria

14. Water-Soluble Vitamins
Vitamin C
Thiamin
Riboflavin
Niacin
Vitamin B6
Folate
Vitamin B12
Pantothenic acid
Biotin
B-Complex

15. Vitamin C Functions: Important to form collagen— Makes some hormones.
a protein substance that provides strength to bones, teeth, skin, etc. and helps heal wounds. Collagen is like cement, holding cells and tissues together.
Makes some hormones.
Strengthens resistance to infection.
Strengthens the immune system
Antioxidant.

16. Vitamin C
Vitamin C content of food is reduced by prolonged storage and cooking—because it is water-soluble and can be destroyed by heat.
Citrus fruit, strawberries, bell peppers, kiwi, broccoli, tomatoes
Certain people need more vitamin C:
smokers, pregnant and breastfeeding women, children, and anyone with fever or infection.
Deficiency causes scurvy (gum disease and broken capillaries in the mouth)

17. Thiamin, Riboflavin, and Niacin
Functions:
All are part of coenzymes needed to get energy from carbohydrate, fats, and protein.
Co-Enzyme = Helping Hand
Needed for normal growth.
Food Sources: Thiamin: pork, beans, watermelon, acorn squash Riboflavin: milk and milk products, eggs Niacin: meat, poultry fish, peanut butter, milk, and eggs

18. Vitamin B6 Functions: Unlike other B-complex, it is stored in muscles
Part of a coenzyme involved in carbohydrate, fat, and protein metabolism —especially crucial to protein metabolism.
Makes hemoglobin in red blood cells—carries oxygen to cells.
Unlike other B-complex, it is stored in muscles
Food sources: broccoli, spinach, some fruits, potatoes, meat fish and poultry
Not well absorbed through plant sources

19. Folate
Functions:
Folate is part of coenzymes required to make DNA
Also needed in new cell production, red and white blood cells, and digestive tract cells
Excellent sources: fortified cereals and breads, green leafy vegetables, and legumes
Meat and dairy contains little folate
Most folate is lost during cooking

20. Folate
Pregnant women are at risk of folate deficiency, which may cause neural tube defects (malformed brain or spine) during first few months of pregnancy.
All women capable of becoming pregnant should take 400 mcg of synthetic folic acid daily from fortified foods (breads) or supplements in addition to natural folate in foods.

21. Vitamin B12
Functions:
Part of a coenzyme needed to make new cells and DNA.
Activates the folate coenzyme.
Ensures normal functioning of the nervous system.
Unlike other vitamins, B12 contains cobalt and is destroyed by microwaving foods
Found only in animal foods

22. Vitamin B12
Vegans typically do not consume enough B12 and can have trouble developing and maintaining normal nerve functions
Vitamin B12 is harder to absorb for elderly, who may need foods fortified with B12 or supplements that use crystalline vitamin B12 (easier to absorb).
B12 deficiency affects nervous system.

23. Pantothenic Acid and Biotin
Functions
Parts of coenzymes involved in energy metabolism
Pantothenic acid is also needed to make lipids, neurotransmitters, and hemoglobin
Biotin is also involved in the metabolism of carbohydrates, fats, and protein
Food Sources
Both pantothenic acid and biotin are widespread in foods
Pantothenic acid: Fortified cereals, beef, poultry, mushrooms, potatoes, tomatoes
Biotin: Egg yolks (Intestinal bacteria make considerable amounts of biotin)

24. Culinary Focus: Fruits and Veggies
Three reasons to eat more fruits and vegetables:
Most fruits and vegetables are major contributors of a number of nutrients that are underconsumed—vitamins A and C, folate, dietary fiber, etc.
Consuming them is associated with less risk of many chronic diseases such as heart disease.
Most fruits and vegetables, when prepared without added fats or sugars, are relatively low in kcalories.

25. Tips for Retaining Vitamins
To get a healthy variety of fruits and vegetables, think color. “Eat the Rainbow”
Store fruits and vegetables properly and use at optimum time for freshness, color, flavor, and nutrition.
Keep most fruits and veggies cold and moist.
Water-soluble vitamins are lost in the cooking medium
Consider cooking methods that do not use liquids or retain the cooking liquid for other uses

26. To Prevent Nutrient Loss in Fruits and Vegetables
Buy fresh, high-quality produce, and check closely when receiving.
Store properly (close up the wrapping tightly to decrease exposure to the air, which pulls out water) and use product when it is still fresh.
When cooking: Avoid peeling, prepare small amounts at a time, cook quickly using appropriate methods such as steaming, cook just until tender.