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The Vitamins.

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Presentation on theme: "The Vitamins."— Presentation transcript:

1 The Vitamins

2 Introduction Vitamins were discovered at the beginning of the twentieth century. Vitamin: An essential, noncaloric, organic nutrient needed in tiny amounts in the diet. The only disease a vitamin can cure is the one caused by a deficiency of that vitamin. Vitamins were discovered at the beginning of the twentieth century. Definition: An essential, noncaloric, organic nutrient needed in tiny amounts in the diet. The role of vitamins is to help make possible the processes by which other nutrients are digested, absorbed, and metabolized or built into body structures. The only disease a vitamin can cure is the one caused by a deficiency of that vitamin.

3 Water Soluble Vitamins
Vitamin C B Vitamins: Thiamin -- Biotin Riboflavin -- Pantothenic acid Niacin B6 Folate (folic acid) B12

4 Water Soluble Vitamins
Digestion, Absorption, and Transport No chemical digestion needed Absorbed in the SI into the capillaries Vitamin B12 must bind with a protein called the intrinsic factor (IF) in the stomach for absorption to occur in the SI No carriers required for transport in the blood

5 Water Soluble Vitamins
Storage and excretion Travel freely in the blood Cells take up water soluble vitamins as needed Limited storage beyond tissue saturation Excess excreted in the urine

6 Water Soluble Vitamins
Deficiency is more common than toxicity for the water soluble vitamins Any toxicity is likely to be due to overuse of vitamin supplements, not food intake

7 Water Soluble Vitamins
Other interesting information: Many are destroyed by light, heat, or exposure to oxygen Best to cook whole in a minimum amount of water Frozen vegetables are often higher in vitamin content than grocery store “fresh” veggies

8 Classifying Vitamins Fat Soluble Vitamins A D E K

9 The Fat-Soluble Vitamins
A, D, E, K Found in fats and oils of foods Require bile for absorption Stored in liver and fatty tissues until needed Not needed in the diet daily Can reach toxic levels if too much is consumed Deficiencies can occur when people eat diets that are extraordinarily low in fat

10 Fat Soluble Vitamins Digestion, Absorption, and Transport
Bile needed to emulsify fat soluble vitamins Form chylomicrons (along with long chain fatty acids and monoglycerides) Chylomicrons are absorbed into the lacteals Travel through lymph system  blood  liver Many require protein carriers to be transported in the blood

11 Fat Soluble Vitamins Other interesting facts:
Found in the fatty parts of food Removed with the fat when low-fat products are made Many low-fat foods are supplemented with these vitamins to make up for this E.g. milk is vitamin A and D enriched

12 The Vitamins For each vitamin we will consider: Functions
Dietary needs and food sources Deficiency Toxicity

13 The B- Vitamins: An Introduction
Thiamin, riboflavin, niacin, pantothenic acid, and biotin – participate in the release of energy from the energy nutrients Folate and vitamin B12 help cells multiply Vitamin B6 helps the body use amino acids to synthesize proteins

14 B Vitamin Deficiencies
In a B vitamin deficiency, every cell is affected. Symptoms include Nausea Severe exhaustion Irritability Depression Forgetfulness Loss of appetite and weight Impairment of immune response Abnormal heart action Skin problems Swollen red tongue Teary, red eyes Pain in muscles

15 Thiamin History Functions: Needed for energy metabolism
E.g. -- required for conversion of pyruvate to acetyl CoA Needed for nerve and muscle function

16 Thiamin Recommended Intake Food Sources 1.1-1.2 mg/day
Found in small amounts in many foods Easily destroyed by heat (cooking) Lost in cooking water Good sources include Pork products, soy, legumes, vegetables, whole grains, watermelon…. (page 311)

17 Thiamin Deficiency Prolonged deficiency leads to beriberi
Results in damage to nervous system and muscles (to include the heart)

18 Thiamin Deficiency Symptoms Beriberi:
Dry form- muscle wasting, poor coordination Muscle weakness Legs heavy, hard to walk, calf pain Apathy, confusion, memory loss Anorexia and weight loss Wet form has additional symptoms of: edema, irregular heart beat, enlarged heart

19 Thiamin Deficiency

20 Thiamin Deficiency Populations at risk: Alcoholics
See in alcoholics who obtain the majority of their calories from alcohol Alcohol inhibits thiamin absorption and hastens its excretion Cultures that eat primarily refined grains (and little else) Thiamin deficient moms  infant deaths

21 In alcoholics thiamin deficiency results in Wernicke-Korsakoff syndrome.
Symtpoms Mental confusion Staggering Rapid eye movements or paralysis of the eye muscles

22 The New York City Poison Control Center at:
The City of New York DEPARTMENT OF HEALTH AND MENTAL HYGIENE Michael R. Bloomberg Thomas R. Frieden, m.d., m.p.h. Mayor Commissioner _______________________________________________________________ nyc.gov/health 2003 Health Alert # 39: A cluster of infantile thiamine (vitamin B1) deficiency (beri-beri) has been reported in Israel among infants fed a vitamin B1-deficient kosher soy-based formula distributed by Remedia. It is possible that this product may be imported into New York City and there may be children in the Orthodox Jewish community who have consumed it. The New York City Department of Health and Mental Hygiene (NYCDOHMH) asks that providers report immediately any suspect case of thiamine deficiency among infants who have been fed this product to: The New York City Poison Control Center at: (212-POISONS) or Please distribute to Pediatric staff in the Departments of Cardiology, Critical Care, Emergency Medicine, Family Medicine, General Pediatrics, Outpatient Pediatrics, Neonatology, Neurology, and Infectious Disease

23 Thiamin Toxicity None known Excess thiamin is excreted and not stored

24 Riboflavin Functions:
Needed for the metabolism of carbohydrates, fats, and proteins Places a role in Kreb’s cycle Part of FAD

25 Riboflavin Recommended Intake: Food Sources: 1.1 – 1.3 mg/day
Destroyed by ultraviolet light (sun light) Good sources include: Milk and milk products Liver Whole grain breads and cereals, oatmeal Clams and squid! Mushrooms (page 313)

26 Riboflavin Deficiency Symptoms
Eyes are inflamed and sensitive to light Cheliosis (cracks at the corners of the mouth) Sore throat Inflammation of the tongue and mouth – painful Inflamed skin, with lesions covered with greasy scales Anemia

27 Riboflavin Deficiency

28 Riboflavin Populations at Risk for Deficiency Toxicity alcoholics
any one with a marginal diet Poor, elderly, eating disorders, drug addicts… Toxicity None reported Excess excreted

29 Niacin Functions Plays an essential role in energy metabolism
Part of NAD Needed by every cell of the body

30 Niacin Recommended Intake: 14 – 16 mg/day of niacin or of NE
NE = Niacin Equivalents Niacin can be made from the essential amino acid tryptophan It takes 60 mg of tryptophan to make 1 mg of niacin Therefore, 1 NE is 60 mg of tryptophan

31 Niacin Food Sources: Sources of complete protein Peanut butter
Dairy, meats, poultry, fish,… Peanut butter Tomato paste Mushrooms Page 315

32 Niacin Deficiency Niacin deficiency disease is called pellagra
Symptoms, 4 D’s: Dermatitis with sun exposure Diarrhea, vomiting Dementia Death Other symptoms: Inflamed, swollen, red, smooth tongue Loss of appetite Page 314

33 Pellagra symptoms: 4 “D’s”
Niacin Pellagra symptoms: 4 “D’s” Diarrhea Dermatitis Dementia Death

34 Niacin Pellegra - Other interesting information
Originally believed to be caused by infection Common up to early 1900’s in US and Europe Many in mental hospitals in south had niacin deficiency, not mental illness Incidence declined in US after WW II when mandatory enrichment of grains began Still common in Africa and Asia Poor bioavailability form corn unless it’s soaked in lime juice

35 Niacin Toxicity Tolerable Upper Intake Level (UL) = 35 mg/day
High doses of niacin are commonly used to treat high cholesterol mg/day recommended for treating high cholesterol

36 Niacin Toxicity Symptoms Niacin flush Excessive sweating Tingling
GI distress Frequent need to urinate May mask prostrate cancer symptoms in men Blurred vision, headaches Liver damage

37 Folic Acid = Folate Functions: Needed for DNA synthesis
Need to make all new cells E.g. Need to make new RBC Reduces incidence of neural tube defects Defects occur in first weeks of pregnancy

38 Folate Plays a role in protein synthesis
Breaks down the amino acid homocysteine High levels of homocysteine increases risk of blood clot formation May reduce risk some cancers Pancreatic cancer in men who smoke Breast cancer in women who drink

39 Folate Absorption and Activation
Folate in foods must be acted upon by an intestinal enzyme for it to be absorbed and transported to cells Folate in cells needs to be activated by vitamin B12 Process also activates the B12

40 Folate Recommended intake: 400 micrograms/day

41 Folate Factors impacting needs Pregnancy -600 mcg/day
Aspirin, antacids, smoking, oral contraceptives reduce absorption Some cancer drugs reduce absorption GI tract damage reduces absorption Occurs with alcoholism, anorexia Poor absorption, leads to even more damage to GI tract

42 Folate Food Sources Cooking destroys up to 50% of folate
Oxygen destroys folate Good sources include: Green leafy vegetables Legumes Fortified cereals and Seeds Liver Orange juice (ok, but not great source) pg 323

43 Folate Folate Deficiency Impairs cell division and protein synthesis
Symptoms: Megaloblastic anemia Fewer red blood cells (RBC) made RBC larger than normal RBC do not carry oxygen as well

44 Folate Deficiency Confusion, irritability, weakness, fatigue
Related to the anemia GI tract deterioration Elevated homocysteine levels Smooth red tongue Increased risk neural tube defects

45 Folate Toxicity No known symptoms May mask a vitamin B12 deficiency
B12 deficiency is VERY serious

46 “Nobel Prize for British Wife”
Vitamin B12 Dorothy Crowfoot Hodgkin Awarded the Nobel prize in chemistry for deducing the structure of vitamin B12 Took her eight years Headline in the London paper announcing this read “Nobel Prize for British Wife”

47 Vitamin B12 Functions: Needed to activate folate
Therefore, needed for DNA and new cell (RBC) synthesis Helps maintain myelin sheath around nerve cells

48 Vitamin B12 Recommended intake: Food Sources*: 2.4 microgams per day
ONLY found naturally in animal products Meat, poultry, fish, eggs, dairy, liver….pg 326 Fortified grains *Easily destroyed by microwave cooking

49 Vitamin B12 Deficiency: Pernicious anemia (VERY SERIOUS)
Megaloblastic anemia Nerve damage  creeping paralysis Smooth sore tongue Fatigue

50 Vitamin B12

51 Vitamin B12 Pernicious anemia frequently goes undiagnosed
Pernicious anemia can be masked by high intakes of folate Generally as supplements

52 B-12 and Folate Presence of immature red blood cells - symptom of folate or vitamin B12 deficiency Extra folate corrects this blood condition B12 deficiency continues Vitamin B12’s other functions then become compromised

53 Vitamin B12 Gastric by-pass patients and vegans are at elevated risk
Takes several years to develop Breast fed infants of vegan mom’s are at elevated risk as well Toxicity: None reported

54 B6 Functions: Need for protein and fatty acid metabolism
Need for amino acid metabolism E.g. For converting tryptophan to other niacin need to make serotonin form tryptophan Helps make RBC Other functions under study May help reduce nausea in 1st trimester

55 B6 Recommended Intake: Food sources: destroyed by heat 1.3 mg/day
UL: 100 mg/day Food sources: destroyed by heat Meat, fish, poultry – animal sources are better absorbed Liver Legumes Seeds and nuts Non-citrus fruits pg 318

56 B6 Deficiency: (rare) Anemia  Weakness and fatigue
Depression, confusion Abnormal brain waves, convulsions Greasy dermatitis

57 B6 Increased risk of deficiency: Alcoholics
Alcohol contributes to increased B6 breakdown and excretion Oral contraceptives may increase risk of B6 deficiency Drug INH inactivates B6 INH used to treat tuberculosis

58 B6 Toxicity: Serious Stored in muscle cells, toxicity seen with supplements Symptoms: Irreversible nerve damage  numbness in hands and feet  Difficult to walk Convulsions Insomnia, restlessness

59 B6 B6 does not help with: Carpal tunnel syndrome PMS
Supplementation above the UL is NOT recommended

60 Biotin Functions: Need for energy metabolism Need to make glycogen
Plays a role in fatty acid and amino acid synthesis

61 Biotin Recommended Intake: Food Sources*: 30 micrograms/day (AI)
Widespread in foods: liver, egg yolk, legumes, fish, mushrooms, whole grains… Some produced by GI tract bacteria *easily destroyed by processing

62 Biotin Deficiency: RARE Skin rash Hair loss Depression Hallucinations
Numbness in legs/arms

63 Biotin Deficiency can be induced by eating LARGE quantities of raw egg whites 2 dozen daily for ~2 months! Prevents biotin absorption Toxicity: none reported

64 Pantothenic Acid Functions: Need for energy metabolism
Part of acetyl CoA Plays a role in the synthesis of many substances: Lipids Hormones Neurotransmitters Hemoglobin

65 Pantothenic Acid Recommended intake: Food Sources: 5 mg/day (AI)
Widespread in foods

66 Pantothenic Acid Deficiency: Rare Toxicity: none known Fatigue
GI distress Insomnia, depression Apathy, irritable Increased sensitivity to insulin Toxicity: none known

67 Vitamin C Functions: Collagen synthesis Antioxidant
Part of scar tissue Strengthens blood vessels Provides matrix for bone growth Antioxidant Need for healthy immune system

68 Vitamin C Functions: Need for thyroxine production
Regulates body temperature and metabolic rate Enhances iron absorption Need to make hemoglobin

69 Vitamin C Recommended intake: Men: 90 mg/day Women: 75 mg/day
Smokers: an extra 35 mg/day More free radicals that need to be “neutralized” UL: mg/day

70 Vitamin C Food sources*: Citrus fruits Strawberries, melon Vegetables
Tomatoes, dark green leafy vegetables, potatoes, broccoli… *Heat and oxygen sensitive Page 329

71 Vitamin C Deficiency:  Scurvy
Poor wound healing - Increased infection Weakness Bleeding gums Loose teeth Broken blood vessels Loss of appetite Joint pain and fragile bones Anemia

72 Deficiency Symptoms

73 Vitamin C Populations at increased risk: Alcoholics Elderly
Babies and toddlers fed only milk/cereals Smokers After illness or stress Fever and stress deplete vitamin C stores

74 Vitamin C Toxicity Symptoms: Diarrhea Cramps, nausea
Headaches, insomnia May interfere with lab tests and meds Increased risk kidney stones Over-absorption of iron

75 Fat Soluble Vitamins A D E K

76 Vitamin A Chemical nature:
Active forms of vitamin A – preformed vit. A Retinol Retinoic acid Retinal Precursor form – provitamin A Beta-carotene Converted to active vitamin A as needed

77 Vitamin A plays a role in
Gene expression Vision Maintenance of body linings and skin Need to build healthy epithelial and mucous tissue Immune defenses Growth of bones and of the body Normal development of cells Plays a role in cell differentiation Reproduction

78 Vitamin A - Functions Vitamin A plays two roles in eye sight:
Process of light perception at the retina Maintenance of a healthy cornea

79 Beta-Carotene Functions beta-carotene;
Can be converted to active vitamin A as needed Antioxidant

80 Vitamin A Recommended intake: 700-900 RAE micrograms/day
RAE = retinol activity equivalents Older unit is IU = International Units See page 360 for conversions between these units UL 3000 RAE UL refers to active vitamin A only, not beta-carotene

81 Vitamin A Food Sources Vitamin A (preformed vit. A):
All animal sources In fatty portion of the food Dairy products Eggs Meat, liver Fortified skim milk and margarine

82 Beta-Carotene (pro-vit A)
Food Sources: All plant sources Yellow/orange/red fruits and vegetables Carrots, apricots, cantaloupe, mangos, pumpkin, sweet potato, winter squash, peppers…… Dark green leafy vegetables Spinach, kale, broccoli, beet greens (but not the beet!)

83 Vitamin A Deficiency Symptoms – eye sight related Night blindness
Leading cause of blindness worldwide ~ ½ million children go blind each year due to a vitamin A deficiency Children with a vitamin A deficiency are more likely to die from complications from measles

84 Eyesight If the vitamin A supply runs low, night blindness can result – a lag before the eye can see again after a flash of bright light at night.

85 Vitamin A Deficiency: Keratinization  dry, cracked skin
Reduced secretions GI tract Bladder Lungs Above symptoms increase risk of infection

86 The skin in vitamin A deficiency
Skin And Body Linings The skin in vitamin A deficiency

87 Vitamin A Deficiency: Anemia Slow bone growth Painful joints
Cracked, cracked teeth Delayed sexual maturity

88 Vitamin A Toxicity: Teratogenic GI distress, weight loss Bone issues
“monster producing” GI distress, weight loss Bone issues Joint pain Stunted bone growth and more

89 Vitamin A Toxicity: Headaches, pressure inside skull Blurred vision
Fatigue, muscle weakness Skin rashes Dry, cracked, bleeding lips Dry, brittle hair

90 Vitamin A Vitamin A toxicity can be fatal
Polar bear liver story Symptoms go away quickly if diet changes Toxicity is never from beta-carotene sources Beta-carotene toxicity…..

91 Beta-carotene toxicity!
Beta-carotene from food is not converted to retinol efficiently enough to cause vitamin A toxicity. Excess beta-carotene is stored the fat under the skin, imparting a yellow cast. Answer: NO

92 Vitamin D Chemical nature: Vitamin D is a sterol
Body can make from cholesterol Requires sunlight exposure 5-10 minutes – light skinned Hour or more if dark skinned Synthesis of vitamin D Involves sunlight, skin, liver, kidney

93 Vitamin D Functions: Bone mineralization Works with other nutrients
Vitamins A, C. K Several minerals

94 Vitamin D Functions: Regulates calcium and phosphorus levels
Stimulates Ca and P absorption in SI Regulates movement of Ca and P in/out of bones Stimulates kidneys to retain Ca and P All of the above are related to bone mineralization

95 Vitamin D Other Functions: Acts as a hormone Not fully understood
Many target organs: Brain and CNS Muscle Reproductive cells…

96 Vitamin D Recommended intake: Depends upon sun exposure and skin color
5-10 micrograms/day (AI) UL: 50 mcg/day

97 Vitamin D Food sources*: Fortified milk and margarine Butter Egg yolks
Liver Fatty fish and fish oils * animal sources

98 Vitamin D Deficiency: Bone abnormalities Kids  rickets
Adults  osteomalcia

99 Vitamin D Populations at risk for deficiency: Inner-city kids
Dark skinned Live in a northern climate Limited sun exposure Elderly Kidney or liver disease Vegans

100 Vitamin D Toxicity: Very toxic Toxicity is never from sun exposure
Can be lethal Milk story Toxicity is never from sun exposure

101 Vitamin D Toxicity Symptoms: Calcium deposits in soft tissue
Muscles, lungs, heart Kidney stones Calcium deposits on walls of arteries Joint pain Frequent urination GI distress

102 Vitamin E Chemical nature: A type of tocopherol 4 forms
Alpha, beta, gamma, delta Alpha-tocopherol is the most active form Other forms have very limited bioactivity

103 Vitamin E Functions: Antioxidant
Component of animal cell membranes Protects unsaturated fatty acids in cell membranes Other roles are not clearly defined, but likely exist

104 Vitamin E Recommended intake: 15 mg/day
Need more if eat more polyunsaturated fats most students did not meet their vitamin E requirement on the day analyzed

105 Vitamin E Food sources*: Vegetable oils Nuts and seeds Whole grains
Green leafy vegetables Liver Wheat germ Egg yolks *easily destroyed by heat and oxygen

106 Vitamin E Deficiency: Rare as most vitamin E is recycled
See in premature babies Transferred from mom to baby in last weeks of pregnancy Cystic fibrosis patients Due to poor fat absorption

107 Vitamin E Symptoms deficiency: Hemolytic anemia
RBC break open Neurological problems with prolonged deficiency Loss of coordination Vision and speech problems Does not prevent/cure MD

108 Vitamin E Vitamin E may help with: Leg cramps
Intermittent claudication Fibrocystic breasts disease “lumpy” breasts

109 Vitamin E Toxicity: Rare
Supplements recommended by many, but not above the UL = 1000 mg 200 mg supplement probably enough May interfere with blood clotting Stop taking supplements prior to surgery Other symptoms: nausea, fatigue, blurred vision

110 VITAMIN K Functions: Need for synthesis of blood clotting proteins
Plays a role in regulation of calcium levels

111 Vitamin K Recommended intake: Sources: 90-120 mcg/day
Made by GI tract bacteria Dark green leafy vegetables, cabbage family Liver Milk

112 Vitamin K Deficiency: rare Symptoms: Populations at risk
Bleeding, hemorrhaging Bone weakness Populations at risk Babies After long-term antibiotic treatment CF

113 Vitamin K Toxicity: rare Occurs with supplement overuse Symptoms:
Take with caution, even if prescribed Symptoms: RBC break open Jaundice Brain damage Interferes with anti-clotting meds


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