CH. 7: VITAMINS: VITAL KEYS TO HEALTH

Enrichment

Means to "add back" nutrients taken out during processing

Fortification

Means to "add extra" nutrients that would not occur naturally

Vitamins

-Needed in small amounts
-Not an energy source
-Individual units rather than long chains
-Essential for normal functioning, growth, and maintenance of the body

What are the fat-soluble vitamins?

A,D,E,K

Fat-Soluble vitamins

-Absorbed with fat into the lymphatic system
-Stored in larger quantities (can overdose)
-Less vulnerable to cooking losses

What are the water soluble vitamins?

B vitamins and vitamin C

Water soluble vitamins

-Absorbed into bloodstream
-Stored in small amounts
-Vulnerable to cooking losses (heat can weaken)

Food preparation affects...

vitamins in foods

Vitamins found in which food groups?

all

Factors that determine amounts of vitamins:

-source (animal vs. plant)
-sunlight
-moisture
-growing conditions
-plant's maturity at harvest
-packaging and storage

What food is enriched?

white bread

What food is fortified?

orange juice

Some enrichment/fortification is required by?

law

Provitamins

-Inactive
-Body must change them to active form
-EX: beta-carotene

Active forms of vitamin A

AKA retinoids
-Retinol
-Retinal
-Retinoic Acid
Precursors: carotenoids

What are the functions of vitamin A?

-Vision
-Maintaining healthy cells
-Fighting infections and bolstering immune function
-Promoting growth and development
-Cell development and health

Vision

*Night and day
-Changes incoming light to visual images
-Keeps eye's surface healthy
-Allows night and color vision

Cell production and differentiation

Regulates production of enzymes, blood carrier proteins, and structural proteins (like those in the skin)

Skin

needed to replace epithelial cells

Immune function

produce immune cells

Reproduction

keeps reproductive tracts healthy

bones

-help produce bone cells
-required for bone remodeling

Dietary recommendations of vitamin A

Retinol Activity Equivalent (RAE)

Sources of Vitamin A

-Animal food sources (retinoids)
-Plant foods (Provitamin A carotenoids)
-Fortified foods

Vitamin A deficiency

-Rare in North America and Western Europe
-Leading cause of child blindness worldwide
-Affects eyes, body cell development, and immune function

Vitamin A deficiency in the eyes

Xerophthalmia

Vitamin A deficiency in the skin and other epithelial cells

Keratin

Vitamin A deficiency effecting immune function

vulnerable to infection

Other effects of vitamin A deficiency

Growth retardation, bone deformities, detective teeth, and kidney stones

Symptoms of vitamin A toxicity

Fatigue, vomiting, abdominal pain, bone and joint pain, loss of appetite, skin disorders, headache, blurred or double vision, and liver damage

Teratogen

-Causes birth defects
-Discoloration of skin

Acne treatment

-Retin-A and Accutane
-use with caution

Forms and formations of vitamin D

activated in liver and kidney

Functions of vitamin D

-bone health
-protects against certain cancers and other chronic diseases
-helps regulate insulin formation/secretion

Sources of vitamin D

-Exposure to sunlight
-Fortified foods (milk, breakfast cereals)
-Supplements

Vitamin D deficiency

-Rickets in children
-Osteomalacia and osteoporosis in adults

Vitamin D toxicity

hypercalcemia

Forms of Vitamin E

-Family of 8 similar compounds
-Only alpha-tocopherol considered for human vitamin E requirement
-Stored mainly in body fat

Functions of Vitamin E

-Antioxidant: protects cell membranes from free radicals
May lower risk of some chronic diseases

Vitamin E

-No major disease associated with Vitamin D deficiency due to adequate levels in American diet
-Major symptom of Vitamin E deficiency is an increase in red blood cell fragility
-Absorbed in intestines

Dietary recommendations for vitamin E

-Related to intake of polyunsaturated fatty acids
-RDA: 15 mg/day for adults
19mg/day for breastfeeding

Food sources of Vitamin E

Nuts, seeds, vegetable oil, whole grain, wheat germ oil, fruit, vegetables, and animal products

Vitamin E deficiency

-Occurs with fat malabsorption or rare genetic disorders
-May also occur post bariatric surgery

Vitamin E toxicity

-Nontoxic and adverse effects have not been found
-Can interfere with blood clotting

Functions of Vitamin K

-Blood clotting
-Bone health

Dietary recommendations for Vitamin K

-Men: 120 mg/day
-Women: 90 mg/day

Food sources of Vitamin K

Green vegetables, plant oils, intestinal bacteria

Vitamin K deficiency

-Rare in healthy people
-Newborn babies at risk

Toxicity of Vitamin K

-Rare
-Can interfere with anticoagulant medicines

8 B vitamins

act primarily as coenzymes in energy metabolism

Vitamin C

-Antioxidant
-Can stabilize Vitamin E

Functions of thiamin (B1)

-Coenzyme in energy metabolism
-Part of the coenzyme thiamin pyrophosphate (TPP)
(Helps break down glucose, make RNA and DNA; helps power protein synthesis/growth)
(Helps synthesize and regulate neurotransmitters/brain function)

Dietary recommendations of thiamin

-Men: 1.2 mg/day
-Women: 1.1 mg/day
-Pregnancy: 1.4 mg/day
-Breastfeeding: 1.5 mg/day

Food sources of thiamin

-Pork, legumes, nuts and seeds, fish and seafood, enriched grain products
-Cooking reduces content

Thiamin deficiency

-Beriberi: overall profound muscle weakness and nerve destruction
-Milder symptoms: headache, irritability, depression, and loss of appetite

Thiamin toxicity

There are no reports of thiamin toxicity

Riboflavin (B2) functions

-Coenzyme in energy metabolism
-Supports antioxidants

Food sources of B2

-Milk and dairy products
-Enriched grains, eggs

B2 deficiency

-Ariboflavinosis
-Occurs most often in chronic alcoholism

B2 toxicity

no reported cases

Functions of Niacin (B3)

-Coenzyme in energy metabolism
-Supports fatty acid synthesis

Food sources of Vitamin B3

-Can be made from amino acid tryptophan
-Whole and enriched grains
-Meat, poultry, fish, nuts, and peanuts

B3 deficiency

-Pellagra: 4 Ds = dermatitis, diarrhea, dementia, and death

Niacin toxicity and medicinal uses

-High doses are used to treat high blood cholesterol
-Side effects: skin flushing, liver damage

What are the functions of Vitamin B6?

-Coenzyme in protein and amino acid metabolism
-Supports immune system
-Helps to lower blood levels of homocysteine (AA by product of meat increases the levels to lead to heart disease, stroke, osteoporosis, and Alzheimer's)

Food sources of Vitamin B6

Meat, fish, poultry, potatoes, fortified meat substitutes, bananas, sunflower seeds

Vitamin B6 to deficiency

microcytic hypochromic anemia

Vitamin B6 toxicity and medicinal uses

Can cause subtle neurological damage, upset stomach, headache, sleepiness, and a tingling, prickling, or burning sensation

Functions of folate

-Coenzyme in DNA synthesis and cell division
-Needed for normal red blood cell synthesis
-Reduces neural tube defects in the unborn

Food sources of folate

-Fortified cereals, enriched grains
-Green leafy vegetables, orange juice, sunflower seeds, and legumes

Folate deficiency

-Anemia and diarrhea (megaloblastic anemia)
-Birth defects (spina bifida)
-Heart disease

Folate toxicity

-Can mask vitamin B 12 deficiency
-Hypersensitive people may suffer hives or respiratory distress

Functions of Vitamin B12

-Needed for normal folate function (DNA and RBC synthesis/metabolize homocysteine)
-Maintains myelin sheath around nerves
-Maintains the CNS which includes the brain and spinal cord

Food sources of vitamin b12

Only animal foods: meats, liver, milk, eggs, some fortified foods such as cereal

Vitamin B 12 absorption

requires adequate stomach acid and intrinsic factor

Vitamin B 12 deficiency

Can lead to pernicious anemia, resulting in nerve damage

Vitamin B12 toxicity

No UL set

Functions of Pantothenic Acid (B5)

Component of coenzyme A

Food sources of B5

-widespread in foods
-reduced by freezing, canning, and refining
*deficiency and toxicity are rare

Functions of biotin

-Coenzyme
-Amino acid metabolism
-Fatty acid synthesis
-Release of energy from fatty acids
-DNA synthesis

Food sources of biotin

-Cauliflower, liver, peanuts, cheese
-Protein avidin (raw egg whites) binds biotin and prevents absorption
*deficiency and toxicity are rare

Function of Choline

Helps metabolize homocysteine (elevated levels associated with heart attack, stroke, and blood clots)

Food sources of choline

-milk, liver, egg yolk, and peanuts
-overall abundant in food

Choline deficiency

unlikely in healthy people

Choline toxicity

Diarrhea, falling blood pressure, and fishy body odor

Vitamin C functions

-Antioxidant
-Needed for collagen synthesis
-Other roles: makes other essential compounds, enhances the absorption of iron from plant foods

Food sources of vitamin C

-Fruits: citrus, strawberries, kiwi, fortified juice
-Vegetables: broccoli, tomatoes, potatoes, cabbage, leafy green, peppers

Vitamin C deficiency

scurvy

Vitamin C toxicity

-May cause GI distress in high doses

Conditional nutrients

-Body makes most substances needed for life
-May need to get from diet due to illness or inherited metabolic errors
-EX: inositol, carnitine, taurine, lipoic acid

Bogus vitamins

-Unnecessary substances found in some supplements
-Marketed as vitamins and health boosters
-EX: Hesperidin - found in fruits
Pangamic acid - may be called vitamin 15
-Rutin - in buckwheat and asparagus