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Water-Soluble Vitamins

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Title: Water-Soluble Vitamins


1
Water-Soluble Vitamins
  • Chapter 13

2
Learning Outcomes
  • Identify the water-soluble vitamins
  • List important food sources for each
    water-soluble vitamin
  • Describe how each water-soluble vitamin is
    absorbed, transported, stored and excreted
  • List the major functions of and deficiency
    symptoms for each water-soluble vitamin

3
Learning Outcomes
  • Describe the toxicity symptoms from the excess
    consumption of certain water-soluble vitamins
  • Distinguish between vitamins and non-vitamins,
    such as carnitine and taurine

4
Overview of Water-Soluble Vitamins
  • Storage in body tissues is minimal
  • Risk of toxicity less than fat-soluble
  • Many of the B vitamins act as coenzymes, which
    are important for energy metabolism

5
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6
Preserving nutrition in water soluble vitamins
T or F Most fruits and vegetables will last
longer if you refrigerate them. T or F You
should trim, cut, and peel fruits and vegetables
shortly after buying them to keep them from
spoiling. T or F The best way to cook
vegetables is to boil them. T or F Organic
fruits and vegetables have more nutrition than
non-organic.
7
Thiamin (B1)
  • Foods
  • Pork, sunflower seeds and legumes
  • Bread and cereals (enriched grains)
  • Needs and upper level
  • RDA 1.2 mg/day men, 1.1 mg/day women
  • Fairly uncommon deficiency in US
  • No UL
  • Absorption in small intestine
  • Transported by RBC as TPP
  • Storage and excretion- little stored, excess
    excreted

8
Thiamin (B1)
9
Thiamin (B1)
  • Functions
  • Thiamin helps the body's cells convert carbohydrat
    es into energy. It is also essential for the
    functioning of the heart, muscles, and nervous
    system.
  • Co-enzyme-thiamin pyrophosphate (TPP)
  • Decarboxylation reactions energy metabolism,
    amino acid metabolism

10
Thiamin (B1)
  • Functions
  • Coenzyme for transketolase
  • Converts glucose to pentose (used to make DNA and
    RNA)

11
Thiamin (B1)
  • Deficiency
  • Beriberi
  • Peripheral neuropathy (dry)
  • Congestive heart failure (wet)
  • Who?
  • 14 days with no thiamin
  • White rice staple food
  • Parental nutrition
  • Severe vomiting and diarrhea
  • Weight loss surgery
  • Wernicke-Korsakoff (Alcohol use)

12
Riboflavin (b2)
  • Foods
  • Milk, enriched grains, eggs and meat
  • Needs and upper level
  • RDA 1.3 mg/day men and 1.1 mg/day women
  • Uncommon deficiency in US
  • No UL
  • Absorption (needs HCl, absorbed in SI)
  • Transport by protein carriers
  • Storage and excretion-mostly excreted in urine

13
Riboflavin (b2)
14
Riboflavin (b2)
  • Functions
  • Co-enzymes flavin mononucleotide (FMN) and
    flavin adenine dinucleotide (FAD)
  • Energy metabolism
  • Citric Acid Cycle
  • Beta oxidation
  • Shuttles H atoms to the electron transport system
  • Other B vitamin functions (niacin, B6, and
    folate)
  • Antioxidant function

15
Riboflavin (b2)
  • Deficiency
  • Ariboflavinosis after 2 months
  • Most often seen in alcoholics, elderly, and
    adolescent girls
  • Light sensitive (milk containers are now plastic
    and cardboard to preserve riboflavin)
  • Use of some types of medications can increase
    riboflavin breakdown (drug used for sleeping and
    seizures)

15
16
Niacin (b3)
  • Foods
  • Available as niacin or synthesized from
    tryptophan
  • Preformed niacin Poultry, meat, fish, and
    enriched grains, some in coffee and tea
  • RDA expressed as niacin equivalents
  • 60 mg tryptophan 1 mg niacin
  • 1 gr of protein 10 mg tryptophan

17
Niacin (b3)
18
Niacin (b3)
  • Needs and upper level
  • RDA 16 mg/day men and 14 mg/day women
  • U.S. intake exceeds RDA
  • UL 35 mg/day applies only to supplements and
    fortification
  • Absorption- passive diffusion
  • Transport-to liver
  • Stored in liver or excreted

19
Niacin (b3)
  • Functions
  • Co-enzymes NAD and NADPH
  • Required for catabolism of carbohydrate, fat and
    protein
  • Required in at least 200 reactions
  • Pharmacological use
  • Nicotinic Acid-lower LDL, increase HDL
  • 1-2 g (60x the RDA)

20
Niacin (b3)
  • Deficiency
  • Pellagra
  • Corn based diets
  • Casals necklace
  • Once a significant problem in the US

21
Niacin (b3) is used in almost every metabolic
pathway
22
Pantothenic Acid (B5)
  • Foods
  • Meat, milk and many vegetables
  • Needs and upper level
  • AI 5 mg
  • Deficiency uncommon in US
  • No UL
  • Functions
  • Co-enzyme A needed to form acetyl CoA and acyl
    carrier protein to build fatty acids
  • Deficiencies are RARE

23
Biotin (B7)
  • Food sources
  • Whole grains, eggs, nuts and legumes
  • Needs and upper level
  • AI 30 micrograms
  • Deficiency uncommon in US
  • No UL
  • Absorption in small intestine
  • Storage in muscle, liver and brain or excreted in
    urine or bile

24
Biotin (B7)
  • Functions
  • Co-enzyme that adds CO2 to compounds
  • Required for metabolism of carbohydrates, fats
    and proteins
  • Deficiency
  • Biotinase enzyme deficiency
  • Skin rash, hair loss, convulsions, impaired
    growth)
  • Excessive consumption (gt12) of raw eggs (avidin)

25
Vitamin B-6 (pyridoxal, pyridoxine, pyridoxamine)
  • Foods
  • Meat, fish, poultry, fortified cereals, potatoes
  • Needs and upper level
  • RDA 1.3 mg/day women 1.7 mg/day men
  • Deficiency uncommon in US
  • UL 100 mg day
  • Permanent nerve damage
  • Absorption via passive diffusion
  • Transport to liver, phosphorylated
  • Storage in liver or excreted

26
Whole Grains better than enriched
27
Vitamin B-6 (pyridoxal, pyridoxine, pyridoxamine)
28
Vitamin B-6 (pyridoxal, pyridoxine, pyridoxamine)
  • Functions
  • Metabolism
  • PLP coenzyme involved in more than 100 enzymatic
    reactions, all involving nitrogen (ie needed for
    amino acid metabolism)
  • Synthesis of compounds
  • Heme, neurotransmitters, vitamins (niacin)
  • Deficiency
  • Very poor diet, alcoholism, medications
    (Parkinsons)
  • Anemia, convulsions, confusion, depression

29
Transamination uses b6
30
Vitamin B-6 (pyridoxal, pyridoxine, pyridoxamine)
  • Pharmacological use
  • Carpal tunnel syndrome
  • PMS (no significant benefit)
  • Nausea during pregnancy

31
Folate (B9)
  • Folic Acid
  • Synthetic sources of folate
  • Foods
  • Liver, legumes and leafy green vegetables
  • Now fortified grains
  • Needs and upper level
  • RDA 400 micrograms/daily
  • Dietary Folate Equivalents (DFE)
  • UL 1 mg
  • May mask B-12 deficiency
  • Concern is with synthetic sources

32
Folate (B9)
33
Folate (B9)
  • Absorption via passive diffusion
  • Transported to liver, travels in blood or bile
  • Excreted in urine or feces
  • Functions
  • Central co-enzyme form tetrahydrofolic acid
    (THFA)
  • DNA synthesis

34
Folate deficiency
  • Megaloblastic anemia
  • Neural Tube defects
  • Maternal deficiency of folate plus genetic
    predisposition
  • All women capable of getting pregnant urged to
    take in 400 micrograms of folic acid
  • Current fortification yields about 200 micrograms
    of folic acid daily

35
Megaloblastic anemia
36
Vitamin B-12 Vitamin B-12 (cobalamin)
  • Foods
  • Animal products
  • Needs and upper level
  • RDA 2.4 micrograms daily
  • Average intake 2-3 times RDA
  • No UL

37
Vitamin B-12 (cobalamin)
  • Absorption, transport, storage and excretion
  • Stomach
  • B12 freed from foods by HCl
  • Free vitamin binds to R-protein
  • SI
  • Pancreatic lipases frees B12 from R-protein
  • Free vitamin binds with intrinsic factor to
    enhance absorption
  • B12-intrinsic factor complex travels to liver
    where it can be stored

38
Vitamin B-12 (cobalamin)
39
Vitamin B-12 (cobalamin)
  • Functions
  • Required for enzymatic reactions
  • Formation of THFA, needed for nucleic acid
    synthesis
  • Formation of methionine from homocysteine, needed
    to metabolize homocysteine and make methyl groups

Methylated Folate
B12
Methionine (methyl groups)
Homocysteine
THFA
Methylated-B12
40
Vitamin B-12 (cobalamin)
  • Deficiency
  • Pernicious Anemia
  • Macrocytic/Megaloblastic Anemia
  • Neurological changes
  • Homocysteine
  • At risk for deficiencies Atropic gastritis
    (elderly) and malabsorption, vegetarians
  • Treatment
  • Monthly injection
  • Nasal gel
  • Oral doses (1-2 mg)
  • Passive diffusion

41
Who would be at most risk for Vitamin B12
deficiency?
  • Someone on the Atkins diet
  • Someone who never eats fruits and vegetables
  • Someone who takes large doses of antacids
  • Someone who drinks alcohol heavily

42
Choline (an essential nutrient although not a b
vitamin
  • Foods-in the form of lecithin (naturally
    occurring and added)
  • Milk, liver, eggs and peanuts
  • Needs and upper level
  • AI 550 mg/daily men 425 mg/daily women
  • Can be synthesized by the body
  • Deficiency is rare
  • UL 3.5 grams (fishy smell, low blood pressure,
    vomiting, GI upset)

43
Choline
44
Choline
  • Absorption in small intestine, then to liver
  • Transport in blood
  • Storage in all tissues
  • Excreted in urine or converted to betaine or
    methyl groups
  • Functions
  • Phospholipids, lipoproteins, cell membranes and a
    pre-cursor to acetylcholine (neurotransmitter)

45
Vitamin C
  • Foods
  • Citrus fruits, peppers and green vegetables
  • Needs and upper level
  • RDA 90 mg/day men 75 mg/day women
  • Smokers need an additional 35 mg/day
  • UL 2 grams/day (GI upset)
  • Absorption efficiency changes with consumption
  • Storage in glands, WBC, eyes, and brain and
    excreted in urine

46
Vitamin C
47
Vitamin C
  • Functions
  • Collagen synthesis
  • Synthesis of other vital compounds (amino acids,
    hormones, carnitine, neurotransmitters)
  • Antioxidant activity (eyes, cancer)
  • Iron absorption
  • Immune function (WBC)

48
Vitamin C
  • Deficiency
  • Scurvy
  • Cancer, heart disease
  • Colds

49
Collagen Synthesis requires vitamin C
50
Vitamins and Cancer
  • Cancer is caused by changes (mutations) to the
    DNA within cells. The DNA inside a cell contains
    a set of instructions telling the cell how to
    grow and divide. Errors in the instructions may
    allow a cell to become cancerous.
  • What do gene mutations do? A gene mutation can
    instruct a healthy cell to
  • Allow rapid growth of mutated genes
  • Fail to stop uncontrolled cell growth
  • Make mistakes when repairing DNA errors

51
Vitamins and Cancer
  • Role of vitamins
  • Prevent DNA damage
  • Control gene expression
  • Play a role in DNA synthesis
  • What foods?
  • Will more of these foods (i.e. supplements)
    protect you further?

52
Role of vitamins
53
Vitamin-like compounds
  • Needed for normal metabolism
  • Synthesized by the body and found in foods
  • Increased need during rapid growth and some
    disease states
  • Often found in infant formulas

54
Carnitine
  • Carnitine
  • Made from lysine and methionine and found in meat
    and dairy
  • Transports fatty acids from cytosol to
    mitochondria for energy metabolism
  • Used as weight loss aid or exercise aid

55
Taurine
  • Taurine
  • Made from methionine and cysteine and found in
    foods of animal origin
  • Functions as antioxidant, helps with insulin
    action, and needed for cell differentiation and
    growth
  • Used in kids with cystic fibrosis and preterm
    infants

56
Table 13_03a
57
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58
Nutrition and Public Health
  • Two most common serious birth defects of the
    spine and brain are spina bifida and anencephaly
  • Incomplete closure/formation of the neural tube
  • 300,000 infants yearly worldwide

59
In 1992, the U.S. Public Health Service Folic
Acid Recommendation
  • All women capable of becoming
  • pregnant should consume 400 micrograms folic acid
    daily
  • 400 mg is the quantity in most multivitamin
    supplements that has been associated with a
    reduced risk in the large observational studies

60
Use and knowledge of folic acid in women of
childbearing age in 1995
  • Heard of folic acid 52
  • Knew folic acid can prevent birth defects 9
  • Knew folic acid should be taken before
    pregnancy 2
  • Took folic acid daily 28

March of Dimes Birth Defects Foundation, Gallup
Polls 1995
61
Folic Acid Fortification
  • The FDA issued a regulation to go into effect by
    January 1998 mandating that all enriched cereal
    grain products (flour, rice, bread, pasta, corn
    grits, corn meal, farina, macaroni and noodle
    products) be added with 140 ?g folic acid/100 g
    of the cereal grain product.
  • This program was designed to increase average
    folate intake by 100 µg/d, although reports have
    indicated it may be closer to 200 µg/d.

62
Effect of fortification in the US on prevalence
of NTDs
Study Results
Honein et al. 2001 19 decrease in NTD rates
Williams et al. 2004 26 decrease in NTD rates
63
Why might increased synthetic folic acid intake
be associated with adverse effects?
  • Folic acid is the synthetic version of the
    vitamin.
  • The safe upper limit (UL) for adults is 1 mg of
    folic acid.
  • Masking a B12 deficiency.
  • High folate intakes can increase the progression
    of cancer in those who already have cancer.
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