Flashcards
Vitamins -lecture 6
Flashcards do conjunto (29)
- 11- Vitamins• essential organic nutrients
• water soluble: Bs & C
• vitamin B1 (thiamin), vitamin B2 (riboflavin), vitamin B3 (niacin), vitamin B5 (pantothenic acid), vitamin B6, vitamin B9 (folic acid, folate) vitamin B12, biotin, vitamin C
• fat soluble: A,D, E & K
• vitamin A ( or the precursor; provitamin A; betacarotene), vitamin D, vitamin E, vitamin K - 21- Vitamins
- 31- Minerals• essential inorganic nutrients
• major minerals:
• calcium, phosphorus, magnesium, sodium,
potassium, chloride, sulphur
• trace minerals or elements:
• zinc, iron, iodine, selenium, copper,
manganese, fluoride, boron, molybdenum - 41- Micronutrient deficiencies may be caused byPrimary food deficiency-
• Soil depletion & Crop failure
• Food storage loss
• Food preparation loss
• Vitamin C: very sensitive to oxidation (esp. whenheated with metals )
• Vitamin B complex: water solubility results in loss in cooking water
• Riboflavin is light sensitive
Diminished food intake-
• Poverty
• Anorexia
• Food beliefs/ fads
• Chronic diseases
Diminished absorption-
• Absorption disorder
• Parasites
• Malignancies
• Increased requirements
Rapid growth-
• Increased physical activity
• Pregnancy
• Hyperthyroidism
Increased loss
• Drug therapy
• Diuresis
• Lactation - 51- Options for effective interventionsFood fortification-
• Requires intervention by governmental
agencies for regulating levels of
fortification and foods to be fortified
• Requires ongoing monitoring
Dietary diversification-
• Introduce nutrient rich foods to the diet
• Change dietary habits
• Encourage growing new foods
• Increase market availability of
specific foods - 6Functions of water-soluble vitamins
- 7Functons of B group and C vitamins
- 8functions of A, D, E and K vitamins
- 9Water soluble vitamins: Bs and C• Found in all types of foods
• Processing may deplete food content
• Absorbed in small intestine
• Absorption often highly regulated by other vitamins or binding proteins in the small intestine
• Excretion in urine
• Not stored to any extent ( except for B6 and B12) so daily intake required and deficiency is often multiple
• Toxicity extremely rare
• Ruminants are generally thought to have lower need of B complex as these may be provided by microflora synthesis.
• Recent research has found that thiamin, niacin and choline supplements may be useful when ruminants are receiving high concentrate and low forage rations
and when they are stressed. - 10Thiamine -Vitamin B1 Increased requirements when:• Pregnancy and lactation
• Eating large amounts of foods that contain the enzyme; thiaminase (destroys thiamin):
• raw sea food (shellfish)
• bracken, causing bracken poisoning in horses
• eating thiaminase containing plants causes cerebrocortical necrosis in cattle and polioencephalomalasia in sheep
• stress situations (high level of exercise, fever, hyperthyroidism)
• Drinking large quantities of tea (contains antagonist)
• Alcoholism- deficiency common in heavy alcohol use - 11Symptoms of thiamine deficiency:• constipation, appetite and weight loss, nausea, short term memory loss and confusion, muscle weakness, fatigue
• Beriberi (from Sinhalese (Sri Lanka), literally ‘I cannot, I cannot’) - 2 major clinical types: Wet Beriberi, Dry Beriberi - 12Riboflavin -Vitamin B2 Deficiency:• seldom seen in industrialized societies
Signs of deficiency when seen:
• in humans; inflamed eyelids, sensitivity to
light, and reddening of the cornea, sore throat and cracks and redness at the corners of the mouth, painful, smooth and purplish tongue and skin lesions covered with greasy scales
• in young pigs- slow growth, vomiting and
rough coat
• in horses- moon blindness and conjunctivitis - 13Niacin -Vitamin B3 Deficiency:Pellagra-
• Man-pellagra-inducing diets: corn meal, corn starch, sweet potatoes, rice, syrup, pork fat (once a common diet in southern states of USA among sharecroppers)
Early stages-
• diarrhoea, abdominal pain, vomiting, inflamed, red tongue, depression, fatigue and headache, reddened skin and rash
• dermatitis in animals and poor feathering in birds
Advanced stages-
• 4 D’s of pellagra:
dermatitis, diarrhoea, dementia, death
• Poultry- chondrodystrophy - 14Pantothenic acid -Vitamin B5 Deficiency:• In all species - reduced growth, loss of hair, intestinal inflammation
• calves- loss of appetite, rough coat, dermatitis and loss of hair around eyes
• pigs- goose stepped gait
• chicks- dermatitis, embryonic death
• dogs- premature greying - 15Pantothenic acid -Vitamin B5 Toxicity:Painful flush, hives and rash, nausea and vomiting and impaired glucose tolerance
- 16Pyridoxine- Vitamin B6 Deficiency:• deficiency difficult to produce in humans (but seen in alcohol abuse) and rare in animals
• scaly dermatitis and mucous membrane lesions, depression, confusion and convulsions, peripheral neuritis
• anaemia - 17Pyridoxine- Vitamin B6 Toxicity:• May occur body builders , PMS sufferers taking large doses
• Skin lesions, depression, fatigue, irritability, headaches, and irreversible nerve damage - 18Biotin -Vitamin B7 Deficiency:• not seen in people who consume a normal diet, may be produced by intestinal bacteria
• biotinidase deficiency: dermatitis, hair loss, loss of appetite avidin excess from raw eggs, binds biotin
• pigs - foot lesions
• poultry - fatty liver and kidney syndrome - 19Folic acid ( Folate -Vitamin B9 ) Deficiency:• Inadequate intake during alcoholism, pregnancy, infancy, teens, the elderly, hospitalization
• Defective absorption (most common) during intestinal disorders
• anaemia- decrease in number of red blood cells, but increase in size (megaloblastic anaemia) in man and rarely in animals sore, red, smooth tongue, diarrhoea and poor growth - 20Cyanocobalamin -Vitamin B12 Deficiency:• rarely due to dietary deficiency (strict western vegans, and their breast-fed infants)
• may be due to pernicious anaemia: caused by gastritis and lack of intrinsic factor
• macrocytic megaloblastic anaemia leading to spinal cord degeneration (irreversible)
• poultry- poor egg hatchability and poor growth and skin / feathering is poor
• pigs- may be required in rations for young pigs
*Must be differentiated from folate deficiency! - 21Ascorbic acid -Vitamin C Deficiency:Scurvy occurs:
• In infants fed exclusively cow’s milk
• In hospital patients
• relatively rapidly (within 1-2 weeks of dietary restriction ) if the patient is already marginally deficient
Symptoms:
• capillary hemorrhages (petechiae), bleeding gums and loose teeth,
• reopening of scar tissue,
• softening of bones, sore joints/bones,
• mental deterioration, anaemia,
• increased infections and poor wound healingbone deformities in fish - 22Ascorbic acid -Vitamin C Toxicity:• rebound scurvy- weaning required
• nausea, abdominal cramps, diarrhoea, headache, fatigue, insomnia
• can interfere with some medical tests, aggravation of gout symptoms - 23Vitamin A -The Retinoids Deficiency:• Night blindness and dry eyes
• Rough, dry, scaly skin (like ‘gooseflesh’)
• Stunted bone growth, shape & unsound teeth
• Immune dysfunction- increased sinus, sore throat, abscesses in ears or mouth
• Reproductive disorders; poor conception & abnormal embryonic growth,
• Rare in industrialized world in man but leading cause of blindness in areas of
poverty
• Sometimes seen in 'over wintered' ruminants towards end of winter when stores run down and animals are fed maize silage/hay/straw which are all low in
betacarotene
• Also common in cattle in range areas in drought where betacarotene content of
grasses is destroyed. Young animals suffer weakness and infections and blindness - 24Vitamin A -The Retinoids Toxicity:• Vitamin A is highly toxic when taken in large amounts either acutely or chronically
• Signs include headache, nausea and vomiting, blurred vision and bulging of the fontanelle in infants
• Skeletal malformations, spontaneous fractures, internal haemorrhages
Hypervitaminosis A in humans-
• Polar explorers eating polar bear or seal liver
• Self-medication and over prescription
• when blood levels of beta-carotene rise- discolours skin - 25Vitamin D Deficiency:*hormone not a vitamin*
Children-
• rickets or osteomalacia- failure of bone
mineralization resulting in ‘bowed’ legs, rib deformities and delayed closing of the fontanelles
• Lax muscles, resulting in muscle spasm and protrusion of abdomen
Adults
• osteoporosis (porous bones) associated with fractures and lower back pain > very serious for the elderly - 26Vitamin D Toxicity:• Toxic dose only 10X higher than the RDI
• Causes hypercalcemia; resulting in hardening of arteries and kidney stones
can lead to cardiac arrhythmias, diminished conscious state - 27Vitamin D Deficiency:• Rare, and result of decreased fat absorption in digestivedisorders
Symptoms are:
• breakdown of RBCs -easy bleeding and bruising, nerve damage
In animals:
• muscle dystrophy, immunodeficiency and male infertility in rats, poultry sheep and swine but not other farm animals or pets
• seen in calves and lambs on whole milk, leading to muscle dystrophy called white muscle disease ( adequate amounts with selenium can
prevent this disorder)
• High dose - initial increase in BP - 28Vitamin D Toxicity:Increases effects of anticlotting medication
- 29Vitamin K Deficiency:• very rare, except in people who have difficulty absorbing fat in their gut or use of antibiotics which kill the bacteria in large intestine
• rare in ruminants, horses and pigs because they generally synthesise sufficient in guts
• causes generalized bleeding, may be deficient in babies at birth (given
injection)
• Dicoumarol and warfarin (rat poison) are antagonists of vitamin K.
Dicoumarol found in mouldy sweet clover causes sweet clover disease
(vitamin K treats this)
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- Degree Introduction to Nutrition (Semester 1 lectures) FlashCards sobre Vitamins -lecture 6, criado por chloe.toto198 em 07-06-2016.
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- chloe.toto198
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