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Vitamins Chapter 7.

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Presentation on theme: "Vitamins Chapter 7."— Presentation transcript:

1 Vitamins Chapter 7

2 Learning Objectives Explain the roles vitamins play in growth and good health List and describe the general functions and food sources of fat-soluble vitamins and water-soluble vitamins List nutrients of concern that many Americans lack in their diets and foods sources of these nutrients

3 Learning Objectives Identify diseases caused by specific vitamin deficiencies Give tips to ensure that vitamin intake is sufficient Identify cooking techniques that promote retention of nutrients and those that cause nutrient loss from foods

4 Vitamins Essential for life and health Needs are small
measured in milligrams (1/1000 of a gram) or micrograms (1/1000 of a milligram) Do not provide energy Must be obtained through food

5 Vitamins All are organic compounds (contain carbon in their structure)
Each vitamin has specific biological functions Absence of each vitamin causes a specific deficiency disease

6 Vitamins 13 are essential nutrients
Must come from food, not made in the body or the body does not make enough Some foods contain precursors that can be converted in the body into vitamins

7 How the Body Uses Vitamins
Facilitate the processes by which other nutrients are: Digested Absorbed Metabolized Built into body structures Absence of a vitamin may cause a nutrient deficiency (symptoms go away when vitamins are replenished through diet)

8 Dangers of Excess Vitamins
Regular intake of high-dose supplements can be dangerous, stressing liver and kidney Amounts found in foods are safe Fat-soluble vitamins are stored, toxicity possible Supplements can interfere with meds/ alter lab tests

9 Two Types of Vitamins 1.) Fat Soluble A, D, E, K 2.) Water Soluble B vitamins -thiamin, riboflavin, niacin, folate, B12, B6, Biotin, Pantothenic Acid Vitamin C

10 Vitamins Minerals Vitamin A Vitamin C Vitamin D* Vitamin E Vitamin K
Shortfall Nutrients – or Nutrients of Concern Many people do not get adequate amounts of: Vitamins Minerals Vitamin A Vitamin C Vitamin D* Vitamin E Vitamin K Calcium* Magnesium Potassium * Sodium* * Biggest nutrient gaps Most diets also lacking dietary fiber Most children and adults get too much sodium

11 Fat soluble vitamins

12 Fat Soluble Vitamins Must be absorbed with fat
Stored in body fat and liver Can build up to toxic levels, especially as supplements in high doses Vitamins A, D, E, K

13 Vitamin A Antioxidant Important roles in: Vision Bone and tooth growth
Reproduction Cell functions Immune system

14 Vitamin A Retinol – active form
liver, egg yolks, dairy foods Precursors include carotenoids – beta-carotene which can be changed to active form in intestine bright orange, yellow, green fruits and vegetables Measured in retinol activity equivalents (RE) it takes 12 mcg of beta-carotene to convert to 1 mcg retinol

15 Vitamin D Some made in body with sunlight
Those who do not have skin exposed to sunlight need more from diet Acts like a hormone to help body absorb and regulate calcium and phosphorus for strong bones, teeth and muscle Several forms: Calciferol D2 = ergocalciferol D3 = cholecalciferol

16 Vitamin D Food sources dairy and other fortified foods, egg yolks
butter, salmon, shrimp, mushrooms 100 IU in 1 cup milk Deficiency fragile bones (osteoporosis) soft bones (osteomalacia), rickets increased cancer risk depression, dementia infections, gum disease

17 Vitamin D Requirements
Dietary Guidelines 2010 600 IU children, most adults 800 IU 70 and older 1000 IU common supplementation recommendation Up to 10,000 IU recommended to replenish for 1-2 weeks, then 1000 IU a day

18 Vitamin E - Tocopherol Antioxidant in cell membranes
especially lungs, brain, blood Sources Seeds, nuts, oils fortified cereals, spinach greens, pumpkin, red bell peppers

19 Vitamin K - Phylloquinone
Intestines make about half of daily need Antibiotics reduce production Needed to make the proteins involved in blood clotting People who take meds to reduce blood clotting may need to adjust intake of foods with vitamin K Works with vitamin D to regulate blood calcium levels and form bone Food sources: green leafy veg (kale, greens, spinach, broccoli)

20 Water soluble vitamins

21 Water Soluble Vitamins
Should be eaten daily None or little stored Excesses usually excreted through urine Excess by supplements can cause increased need


23 The B Vitamins

24 B Vitamins- General Functions
Metabolize Energy as Coenzymes(catalysts) release calories from carbohydrates, protein and fats Necessary to form red blood cells, heal wounds Growth and development Nerve functions Proper digestion and appetite

25 B Vitamins Continued.. B vitamins found in most protein foods, leafy green vegetables and grain (enriched) products Enrichment- replaces thiamin, riboflavin, niacin Generally little stored in the body Oversupply or deficiency of one B vitamin can effect need and use of others

26 Thiamin- B1 Critical role in energy metabolism
Necessary for nerve and heart function

27 Riboflavin- B2 Essential for metabolism of carbohydrates to produce energy Milk, dairy and organ meats are rich in riboflavin. Light destroys riboflavin. Dairy should be in containers that block light

28 Niacin- B3 Essential for metabolism of carbohydrates to produce energy
Body can make niacin by converting tryptophan (essential amino acid) Niacin- high doses can cause itching, flushing, liver damage, high blood sugar

29 Pantothenic Acid- B5 Coenzyme in metabolic processes
Deficiencies Uncommon No toxicities reported

30 Pyridoxine- B6 Part of coenzyme necessary for metabolism of carbohydrates, fat and protein Necessary for nervous and immune system Needed to convert tryptophan to niacin Needed to make hemoglobin

31 Vitamin B12 Assists in bone-blood cell formation Protects nerve fibers
Pernicious anemia Protects nerve fibers Carbohydrate, protein, fat energy metabolism Needs intrinsic factor for absorption Found in animal foods, fortified in vegetarian. Vegans should B12 supplement

32 Folate Part of coenzymes necessary to form DNA
Important for red blood cell formation Helps the body use protein

33 Folate Food Sources: legumes, oranges, green leafy vegetables, enriched grains, asparagus, beets Some lost in cooking Fortification- adds folacin to grain foods. Folacin- more stable form Critical in early pregnancy to prevent birth defects Part of coenzymes necessary to form DNA Women of child bearing age need supplemented folate

34 Vitamin C – Functions Helps make collagen (protein that stabilizes cell walls) Helps keep gums and other tissues healthy Aids in the healing of cuts and wounds Helps the body absorb iron Necessary to form thyroxin (hormone that regulates metabolic rate)

35 Vitamin C Shortfall nutrient because many Americans do not eat enough fruits and vegetables More needed by: Pregnant and lactating women Smokers Infections, fevers or wound healing

36 Food Issues Related to Vitamin C
Least stable nutrient. Destroyed by: Heat Leaching into water while cooking Evaporation Some juices and cereals fortified with Vitamin C Supplements in high doses may cause gastrointestinal symptoms

37 Vitamin C - Sources Excellent sources include: Red bell peppers
Oranges Grapefruit Broccoli Strawberries Papaya Brussels sprouts Fortified cereal or juices Tomatoes

38 Bioavailability is Influenced By:
Nutritional status - if you are deficient your body will absorb more Other nutrients at the same meal- compete for protein carriers needed for absorption Nutrients in high dose supplements are not used as well as nutrients in foods Binders such as oxylates and phytates

39 Nutrient Bioavailability Enhanced By:
The form of a nutrient; vitamin D3 is absorbed better than D2 Fermentation processes Ex. miso and tempeh, may improve iron bioavailability Food preparation techniques soaking and sprouting beans, grains and seeds, leavening bread, can reduce binding of zinc by phytic acid and increase zinc bioavailability Organic acids Ex. citric acid can enhance zinc absorption

40 Nutrient Bioavailability is Reduced By:
Too much of one mineral can reduce the absorption of another Polyphenols in regular and herbal teas, coffee and red wine bind some iron Cooking softens cell walls of food so more nutrients released

41 Nutrient Retention – Purchase Forms
Canned: Canned foods are packed at their peak of freshness and due to the absence of oxygen during their storage period, canned fruits and vegetables have a longer shelf life and remain relatively stable up until opened. Fresh: Fresh is best if consumed within a short time after purchasing. Frozen: Frozen products are packed at their peak of nutrition and freshness. At least equal to fresh in nutrients.

42 Nutrient Retention – In the Kitchen
To retain nutrients: keep fresh produce chilled and covered Peel only when necessary. Peeling removes nutrients and fiber of peel and under peel Use pulp in citrus rather than straining it out Purees and coulis increase nutrient availability by breaking cell walls Serve cooked vegetables immediately after cooking – holding causes nutrient losses

43 Nutrient Retention – In the Kitchen
Reserve liquids from cooked vegetables and add to stocks, sauces, etc Fry as little as possible. High heat destroys some nutrients and creates free-radicals Drain and rinse canned beans to reduce sodium Drain brines from capers, pickles and other foods packed in salted liquids

44 Chapter 7: Vitamins, Minerals and Phytochemicals
Discussion Questions and Answers Assignments

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