Transcript The Water-Soluble Vitamins

The Water-Soluble
Vitamins
B Vitamins
and
Vitamin C
Copyright 2005 Wadsworth Group, a division of Thomson Learning
The Vitamins
Copyright 2005 Wadsworth Group, a division of Thomson Learning
The B Vitamins
Chief Functions - important as
coenzymes
- Thiamin, riboflavin, niacin,
pantothenic acid & biotin
involved in energy metabolism
- Vitamin B-6 involved in protein
metabolism
- Folate & Vitamin B-12 involved
in cell replication
- Therapeutic doses of niacin
lower cholesterol
The B Vitamins
• Coenzymes
Copyright 2005 Wadsworth Group, a division of Thomson Learning
Thiamin
• Other names: Vitamin B1
• Chief functions in the body
– Part of coenzyme TPP (thiamin
pyrophosphate) used in energy
metabolism
• 1998 RDA
– men: 1.2 mg/day
– women: 1.1 mg/day
Copyright 2005 Wadsworth Group, a division of Thomson Learning
Thiamin
Sources
-Whole grain,
fortified, or
enriched grain
products
-Moderate
amounts in
all nutritious
food
-Pork
-Easily
destroyed by
heat
Copyright 2005 Wadsworth Group, a division of Thomson Learning
Thiamin
• Deficiency disease
– Beriberi
• Wet, with edema
• Dry, with muscle wasting
• problem in SE Asia
where diet is high in polished rice
• Deficiency symptoms
– Enlarged heart, cardiac failure
– Muscular weakness
– Apathy, poor short-term memory,
confusion, irritability
– Anorexia, weight loss
• Toxicity symptoms: none reported
Copyright 2005 Wadsworth Group, a division of Thomson Learning
Riboflavin
• Other names: Vitamin B2
• 1998 RDA
– Men: 1.3 mg/day
– Women: 1.1 mg/day
• Chief functions in the body
– Part of coenzymes FMN (flavin
mononucleotide) and FAD (flavin
adenine dinucleotide) used in energy
metabolism.
Copyright 2005 Wadsworth Group, a division of Thomson Learning
Riboflavin
Sources
-Milk products
(yogurt,
cheese)
-Enriched or
whole
grains
-Liver
-Easily destroyed
by ultraviolet light
and irradiation
Copyright 2005 Wadsworth Group, a division of Thomson Learning
Riboflavin
• Deficiency symptoms
– Inflamed eyelids and sensitivity to
light, reddening of cornea
– Sore throat
– Cracks and redness at corners of
mouth
– Painful, smooth, purplish red tongue
– Inflammation characterized by skin
lesions covered with greasy scales
• Toxicity symptoms: none reported
Copyright 2005 Wadsworth Group, a division of Thomson Learning
Niacin
• Other names
– Nicotinic acid
– Nicotinamide
– Niacinamide
– Vitamin B3
• Precursor: dietary tryptophan
• Chief functions in the body
– Part of coenzymes NAD (nicotinamide
adenine dinucleotide) and NADP (its
phosphate form) used in energy
metabolism
Copyright 2005 Wadsworth Group, a division of Thomson Learning
Niacin
• 1998 RDA
– Men: 16 mg NE/day
– Women: 14 mg NE/day
• Upper level for adults:
35 mg/day
Niacin
Sources
Milk, eggs,
meat, poultry,
fish
Whole-grain
and enriched
breads and
cereals
Nuts
All proteincontaining foods
Copyright 2005 Wadsworth Group, a division of Thomson Learning
Niacin
• Deficiency disease: pellagra
Widespread in south before 1920
where diet is high in corn & low in
protein
• Deficiency symptoms
– Diarrhea, abdominal pain, vomiting
– Inflamed, swollen, smooth, bright red
tongue
– Depression, apathy, fatigue, loss of
memory, headache
– Bilateral symmetrical rash on areas
exposed to sunlight
Copyright 2005 Wadsworth Group, a division of Thomson Learning
Niacin
• Toxicity symptoms
– Painful flush, burning, tingling
sensation, hives, and rash (“niacin
flush”)
– Excessive sweating
– Blurred vision
– Liver damage, impaired glucose
tolerance
Copyright 2005 Wadsworth Group, a division of Thomson Learning
Biotin
• 1998 adequate intake (AI)
– Adults: 30 g/day
• Chief functions in the body
– Part of a coenzyme used in energy
metabolism, fat synthesis, amino acid
metabolism, and glycogen synthesis
• Significant sources
– Widespread in foods
– Organ meats, egg yolks, soybeans,
fish, whole grains
– Also produced by GI bacteria
Copyright 2005 Wadsworth Group, a division of Thomson Learning
Biotin
• Deficiency symptoms
– Depression, lethargy, hallucinations,
numb or tingling sensation in the
arms and legs
– Red, scaly rash around the eyes,
nose, and mouth
– Hair loss
• Toxicity symptoms: none reported
Copyright 2005 Wadsworth Group, a division of Thomson Learning
Pantothenic Acid
• 1998 adequate intake (AI)
– Adults: 5 mg/day
• Chief functions in the body
– Part of coenzyme A, used in energy
metabolism
• Significant sources
– Widespread in foods
– Organ meats, mushrooms, avocados,
broccoli, whole grains
• Easily destroyed by food processing
Copyright 2005 Wadsworth Group, a division of Thomson Learning
Pantothenic Acid
• Deficiency symptoms
– Vomiting, nausea, stomach cramps
– Insomnia, fatigue, depression,
irritability, restlessness, apathy
– Hypoglycemia, increased sensitivity to
insulin
• Toxicity symptoms: none reported
Copyright 2005 Wadsworth Group, a division of Thomson Learning
Vitamin B6
• Other names
– Pyridoxine
– Pyridoxal
– Pyridoxamine
• Chief functions in the body
– Part of coenzymes PLP (pyridoxal
phosphate) and PMP (pyridoxamine
phosphate) used in amino acid and
fatty acid metabolism
– Helps to convert tryptophan to niacin
and to serotonin
– Helps to make red blood cells
Copyright 2005 Wadsworth Group, a division of Thomson Learning
Vitamin B6
• 1998 RDA
–Adults (19-50 years):
1.3 mg/day
• Upper level for adults:
100 mg/day
Copyright 2005 Wadsworth Group, a division of Thomson Learning
Vitamin
B6
Sources
Potatoes,
legumes,
noncitrus
fruits
Fortified
cereals
Liver
Soy products
Meats, fish,
poultry
Copyright 2005 Wadsworth Group, a division of Thomson Learning
Vitamin B6
• Deficiency symptoms
–Scaly dermatitis
–Anemia (small-cell type)
–Depression, confusion,
abnormal brain wave pattern,
convulsions
Copyright 2005 Wadsworth Group, a division of Thomson Learning
Vitamin B6
• Toxicity symptoms
–Depression, fatigue, irritability,
headaches
–Nerve damage causing
numbness and muscle weakness
leading to an inability to walk
and convulsions (progressive
sensory ataxia)
–Skin lesions
Copyright 2005 Wadsworth Group, a division of Thomson Learning
Folate
• Other names
– Folic acid
– Folacin
– Pteroylglutamic acid (PGA)
• Chief functions in the body
– Part of coenzymes THF
(tetrahydrofolate) and DHF
(dihydrofolate) used in DNA synthesis
and therefore important in new cell
formation
Copyright 2005 Wadsworth Group, a division of Thomson Learning
Folate
• 1998 RDA
–Adults: 400 g/day
• Upper level for adults:
1000 g/day
Folate
Sources
Fortified grains
Leafy green
vegetables,
legumes, seeds
Liver
Copyright 2005 Wadsworth Group, a division of Thomson Learning
Folate
• Deficiency symptoms
–Anemia (macrocytic or large-cell
type)
–Smooth, red tongue
–Mental confusion, weakness,
fatigue, irritability, headache
• Toxicity symptoms
–Masks vitamin B12-deficiency
symptoms (nerve damage)
Copyright 2005 Wadsworth Group, a division of Thomson Learning
Folate
Protective effect
• Heart Disease
• Cancer
• Spina bifida
Folate
• Neural tube defects in pregnancy
–Spina bifida
Copyright 2005 Wadsworth Group, a division of Thomson Learning
Vitamin B12
• Other names: cobalamin (and
related forms)
• Chief functions in the body
– Part of coenzymes methylcobalamin
and deoxyadenosylcobalamin used in
new cell synthesis
– Helps to maintain nerve cells
– Reforms folate coenzyme
– Helps to break down some fatty acids
and amino acids
Copyright 2005 Wadsworth Group, a division of Thomson Learning
Vitamin B12
• 1998 RDA
–Adults: 2.4 g/day
• Absorption
–HCl
–Pepsin
–Intrinsic factor
Copyright 2005 Wadsworth Group, a division of Thomson Learning
Vitamin B12
• Significant sources
–Animal products (meat, fish,
poultry, shellfish, milk, cheese,
eggs)
–Fortified cereals
• Easily destroyed by microwave
cooking
• Deficiency due to vegan diet or
lack of intrinsic factor
Copyright 2005 Wadsworth Group, a division of Thomson Learning
Vitamin B12
• Deficiency disease: pernicious
anemia
• Deficiency symptoms
–Anemia (large-cell type)
–Fatigue, degeneration of
peripheral nerves progressing
to paralysis
• Toxicity symptoms: none
reported
Copyright 2005 Wadsworth Group, a division of Thomson Learning
Vitamin B12
• Deficiency of folate or B12 produces
pernicious anemia
Copyright 2005 Wadsworth Group, a division of Thomson Learning
Vitamin C
• Other name: ascorbic acid
• Chief functions in the body
– Collagen synthesis
• Strengthens blood vessel walls, forms
scar tissue, provides matrix for bone
growth
– Antioxidant
– Thyroxin synthesis
– Amino acid metabolism
– Strengthens resistance to infection
– Helps in absorption of iron
Copyright 2005 Wadsworth Group, a division of Thomson Learning
Vitamin C
• 2000 RDA
– Men: 90 mg/day
– Women: 75 mg/day
– Smokers: + 35 mg/day
• Upper level for adults:
2000 mg/day
• Needs increase with
infection, burns,
surgery & smokers
• Easily destroyed by
heat and oxygen
Copyright 2005 Wadsworth Group, a division of Thomson Learning
Vitamin C
Sources
Citrus fruits
Cabbage-type
vegetables, dark
green vegetables
(such as bell peppers
and broccoli)
Cantaloupe,
strawberries
Lettuce, tomatoes,
Copyright 2005 Wadsworth Group, a division of Thomson Learning
Vitamin C
• Deficiency disease: scurvy
• Deficiency symptoms
– Anemia (small-cell type)
– Atherosclerotic plaques
– Pinpoint hemorrhages under the skin,
bone fragility, joint pain
– Poor wound healing, frequent
infections, bleeding gums, loosened
teeth
– Muscle degeneration and pain,
hysteria, depression, rough skin,
blotchy bruises
Copyright 2005 Wadsworth Group, a division of Thomson Learning
Vitamin C
• Toxicity symptoms - >2 gms/day
–Nausea, abdominal cramps,
diarrhea
–Headache, fatigue, insomnia
–Hot flashes, rashes
–Interference with medical tests
(false-negative urine glucose
test), aggravation of gout
symptoms, urinary tract
problems, kidney stones
(oxalate)
Copyright 2005 Wadsworth Group, a division of Thomson Learning
Vitamin And
Mineral Supplements
• Who needs supplements?
Copyright 2005 Wadsworth Group, a division of Thomson Learning
Vitamin And
Mineral Supplements
• Arguments for supplements
–Correct overt deficiencies
–Improve nutrition status
–Reduce disease risks
–Support increased nutrient needs
–Improve the body’s defenses
Copyright 2005 Wadsworth Group, a division of Thomson Learning
Vitamin And
Mineral Supplements
• Arguments against supplements
–Toxicity
–Life-threatening misinformation
–Unknown needs
–False sense of security
–Other invalid reasons
Copyright 2005 Wadsworth Group, a division of Thomson Learning
Vitamin Supplements
1. Healthy people who eat healthy
diets do not require supplements
2. Many B vitamins are lost when
grains are refined but some added
back (enrichment or fortification);
now deficiency usually only occurs
due to poverty, illness, alcohol
abuse
3. Toxicities – usually results from
misuse of supplements
Vitamin Supplements
4. Unless a specific nutritional problem
exists, a single, balanced multivitamin/mineral preparation that
provides 100% Daily Value should
suffice
5. The only disease a vitamin will cure
is the one caused by a deficiency of
that vitamin
Vitamin Supplements
Some individuals who may benefit:
1. Low energy intake
2. Illness/injury
3. Absorption problems
4. Certain medications
5. Strict vegetarian
6. Pregnant/lactating
7. Newborn & breastfed infants
Vitamin And
Mineral Supplements
• Regulation of
supplements
• Selection of
supplements
-Form
-Contents
-Misleading
claims
-Cost
Copyright 2005 Wadsworth Group, a division of Thomson Learning