vitamins ii
TRANSCRIPT
VITAMIN DEFICIENCY AND EXCESS
vitamins
Vitamins are the organic substances in food, which are required in very small amounts and are not synthesized by the body.
They occur naturally in food and are essential for good health.
Vitamins are broadly categorized into two forms
Fat soluble vitamins – Vitamin A,D,E and K Water soluble – Vitamin B complex and
vitamin C
VITAMIN A(RETINOL)
Liver is the richest source,fish,eggs Green leafy vegetables, carrots, and yellow fruits Plays an important role in vision. Retinaldehyde is the
part of the photoreceptors of rods in retina Vitamin A is also necessary for normal growth, fetal
development, fertility, haemopoiesis and immune function
DEFICIENCY Causes- Nightblindness Xerophthalmia Bitot’s spots Corneal ulceration and necrosis Keratomalacia with scarring leading to blindness
Deficiency is treated by a single large dose of retinol as palmitate or acetate 200000 IU orally or IM
Xerophthalmia – 60mg of vit A in oily soln
TOXICITY of vitamin A causes liver damage,hyperostosis and teratogenicity.
Acute overdose can cause nausea and headache, raised intracranial pressure and skin desquamation.
Excessive intake of carotene causes hypercarotenosis (pigmentation of skin)
VITAMIN D
Natural form of Vitamin D is cholecalciferaol. It is formed in the skin by the action of ultraviolet rays on 7-dehydrocholesterol.
Dietary sources are egg yolk , fish oil, butter and milk.
Cholecalciferol is not biologically active. It is converted in the liver to 25-hydroxycholecalciferol which is further hydroxylated in kidneys to 1,25 dihydroxycholecalciferol. This is the active form of vitamin D
Functions Vitamin D helps in uptake of calcium
from the gut and bone formation Maintains normal functioning of
muscles, immune function and inflammation.
DEFICIENCY leads to poor bone mineralization causing rickets in children and osteomalacia in adults.
Deficiency occurs due to malabsorption or chronic renal disease
TOXICITY leads to hypercalcaemia leading to renalcolic ,polyuria, polydipsia,lethargy,nausea, depression, drowsiness
VITAMIN E
α- tocopherol is the active form of vitamin E in human body.
FUNCTIONS• The main function of vitamin E is anti oxidant. It
intercepts free radicals & prevents destruction of cell membrane.
• It prevents the oxidation of PUFA by free radicles.
• It is involved in anti-inflammatoy and immune systems.
• It inhibits platelets aggregation.
• It enhances vasodilatation.
Vitamin E Dietary Sources Vegetable oils
Almonds & peanuts
sunflower oil
Spinach
Carrots (least)
Vitamin E deficiency
•Severe vitamin E deficiency causes: Neurological symptoms (impaired coordination) & muscle weakness causing ataxia.
Increased risk of cardiovascular diseases
Visual scotomas
Deficiency occurs in severe PEM and fat malabsorption syndrome
Deficiency is t/t by 800-1200mg of tocopherol/d
THERAPEUTIC USES
Prevention of cardiovascular diseases
Diabetes Mellitus
Cancer prevention
Boost immunity
Dementia
TOXICITY
Excess vitamin E may cause:
Impaired blood clotting leading to increased risk of bleeding in some persons.
It is recommended that vitamin E supplements to be stopped one month before elective surgery.
VITAMIN K
The K is derived from the German word Koagulation.
There are 2 naturally occurring forms of vitamin K. Plants synthesize phylloquinone (vitamin K1) & bacteria synthesize menaquinone-3 (vit K2).
FUNCTIONS•Vitamin K is needed for production of vitamin K-dependent coagulation factors in the liver.
•Other functions include:
Assist in bone mineralization. The mineral binding capacity of osteocalcin requires vit K.
SOURCES OF VITAMIN K
Bacteria in large intestine produce vit K2 and supply 40-50% of human requirement.
Vegetable oils
Almonds & peanuts
Avocado & Broccoli
Spinach, Lettuce.
Vitamin K deficiency
deficiency leads to delayed coagulation and bleeding.
Is uncommon in adults. Only those with severe liver disease (obst. Jaundice) chr. Small intn dis & those on oral anticoagulants are at risk.
Exclusively breast fed & premature babies are at risk coz human milk is low in vitamin K.
Hemorrhagic disease of the newborn is a serious threat to life & routine vit k prophylaxis is recommended.
VITAMIN C Humans, unlike other mammals, are unable to make ascorbic acid & they get it from food.
Rich dietary sources are citrus juices (orange, grapefruit & lime), strawberry, Guava, tomato, sweet red pepper & broccoli.
Recommended daily intake is between 15-120 mg/day depending on age. Smokers & lactating mother needs the higher range.
FUNCTIONS
Collagen synthesis
Antioxidant property
promotes absorption of non-heme ironConnective tissue metabolism
Vitamin C deficiency
Severe deficiency leads to Scurvy with the following manifestations:
Bleeding & bruising easily- swollen bleeding gums, petechial h’ges,ecchymosis
Joint pain & swelling
Poor wound healing
Fatigue & lack of concentration
• Cardiovascular diseases
• Cataracts
• Diabetes Mellitus
• Cancer prevention
• Common cold
Treatment -250 mg vit C 8hrly
THERAPEUTIC USES
VITAMIN B Complex
Thiamine (Vit. B1)
Known as B1 cause first identified. Function – important role in
peripheral nerve conduction. Food sources– pork, meat, yeast,
beef, legumes, whole grains, nuts. Deficiency – poor intake, chronic
illness, chronic alcoholism, hyperemesis, bariatric surgery.
Signs and symptoms – anorexia, irritability
and Beri BeriTypes of Beri Beri --- wet, dry and infantileWet type – Cardiovascular symptoms, Cardiomegaly, tachycardia, CCFDry type – symmetrical peripheral neuropathy
In alcoholics – chronic deficiency causes CNS manifestations like horizontal nystagmus, ophthalmoplegia, cerebellar ataxia, mental impairment known as Wernicke’s Encephalopathy.
Wernicke’s Encephalopathy with loss of memory and psychosis is known as Wernicke’s Korsakoff’s syndrome
TREATMENT– acute deficiency 100 mg/day IM for 7 days f/b 10
mg/day till recovery.
Riboflavin (Vit. B2)
Important for metabolism of CHO,fat,proteinsDeficiency causes-- Lesions of mucocutaneous surface of oral cavity and skin, Corneal vascularization, Anemia and Personality changes Sources are-- Milk and dairy products, Enriched breads, Cereals, Fish, Eggs, Broccoli and LegumesToxicity– not known becoz GI absorption is verylimited.
Niacin (Vit. B3)
Refers to nicotinic acid nicotinamide and derivatives. They are precursors of NAD and NADP which are important in oxidation and reduction reactions in the body.
Sources—beans, milk, meat, eggs Deficiency causes Pellagra Common in corn eating population,
alcoholics Hartnup’s disease, carcinoid syndrome
S/S of Pellagra
Loss of appetite, gen weakness, irritability abdominal pain and vomiting
Red tongue Characteristic skin rash, pigmented
and scaling skin(rash known as Casal’s necklace)
Diarrhea, dementia,depression,seizures
Severe Pellagra--3Ds leading to death dermatitis diarrhea dementia
Treatment – 100 -200 mg of nicotinamide TDS daily for 5 days
Pantothenic Acid (Vit. B5) Component of co-enzyme A Source– liver, yeast, egg yolk, whole
grains, vegetables Deficiency—GI disturbances,
depression, muscle cramps paresthesias, ataxia
No toxicity known
Pyridoxine (Vit B6)
It is a cofactor for many enzymes involved in amino acid metabolism
Synthesis of heme and neurotransmitters
Metabolism of glycogen, lipids, steroids and several vitamins.
Sources– legumes, nuts, wheat bran, meat . Bioavailability is more in animal sources.
Deficiency Epithelial changes, Depression, confusion Microcytic hypochromic anemia due to
reduced heme Hyperhomocystenemia -increased risk of
CV disease In infants diarrhea ,seizures Some drugs like
INH ,penicillamine ,alpha dopa
Toxicity Sensory neuropathy Photosensitivity Treatment RDA--- 1.5-- 2 mg/day 100mg im daily for seizures
Folic Acid (Vitamin B9)
Functions:1. Needed for RBC & DNA formation, cell multiplication
esp. GI cells2. Newly discovered functions:
a. Prevents neural tube defectsb. Prevents heart disease (reduces homocysteine
levels)c. Prevents colon cancer
Etiology: Peak incidence 4-7 months Deficient dietary intake: goat’s milk deficient &
powdered milk poor source Sources are liver, green leafy veg, and fortified cereals.
DEFICIENCYDeficient absorption as in celiac
disease, achlorhydria, anticonvulsant drugs and zinc deficiency
hypothyroidism, drugs like trimethoprim & alcoholism
Increased requirement during rapid growth & infection
Asso with vitamin B12 deficiency & chronic alcoholism
Increased destruction possible in cigarette smoking
Folic Acid Deficiency
Clinical Manifestations:1.Megaloblastic anemia w/ irritability,
failure to gain wt & chronic diarrhea2.Thrombocytopenic hemorrhages
advanced cases
RDA: 20-50mcg/24 hrs
Treatment:3.Parenteral folic acid 2-5mg/24 hrs,
response in 72 hrs, therapy for 3-4 wks4.Transfusions only when anemia severe
Cobalamine (Vitamin B12)
Vitamin B12 is absorbed from the terminal ileum in presence of intrinsic factor
Deficiency occurs in elderly patients, alcoholics, malabsorption, drugs like neomycin
Clinical Manifestations of deficiency:1. Megaloblastic anemia 2. Neurological includes ataxia, paresthesias,
hyporeflexia, Babinski responses, clonus & coma
3. Tongue smooth, red & painful
RDA: Infants 0.5 mcg/dayOlder children & adults 3mcg/day
Treatment:1. Prompt hematological response w/
parenteral vitamin B12 1-5mcg/24hrs2. If there is neurological involvement
1mg IM daily for at least 2wks3. Pernicious Anemia: Monthly vitamin
B12 1mg IM necessary throughout patient’s life
TRACE ELEMENTS
CALCIUM Dietary sources – milk ,cheese,
yoghurt, eggs, fish, almonds, peanuts, peas and beans
Calcium absorption is impaired in vit. D deficiency, malabsorption and some foods like spinach
Deficiency causes impaired bone mineralization in children and increased bone loss in adults
phosphorus
Dietary deficiency is rare Phosphates are added to processed
foods Deficiency occurs in premature
infants, renal tubular phosphate loss. Deficiency causes
hypophosphatemia and muscle weakness
IRON
Needed in formation of Hb, and involved in many enzymatic reactions.
Dietary sources are red meat, liver, fish, shellfish,oatmeal, legumes, nuts, dried fruits
Normal daily loss is 1 mg by desquamated surface cells and intestinal loss.
30 mg of iron is lost in menstruation Daily intake of 8 mg Vitamin C enhances iron absorption Overload of iron leads to haemochromatosis
and liver cirrhosis
IODINE
Sources are sea fish, seaweed and plants grown near the sea.
Deficient in mountainous regions. Deficiency cause IDD, goitre is
common, congenital hypothyroidism, deafness, poor reflexes and poor learning
ZINC
Present in meat, shellfish, nuts and legumes Zn helps in synth and stabilization of protiens Deficiency is seen in PEM, malabsorption
syndromes, alcoholics and alcoholic liver disease.
Deficiency is characterized by growth retardation, hair loss, chronic diarrhea ,muscle wasting and, mental apathy.
Zn promotes general well being, healing of skin lesions and improves appetite
SELENIUM
Prevents free radical damage to the cells.
Takes part in conversion of thyroxin to triiodothyronine in liver
Deficiency – hypothyroidism, cardiomyopathy in children and myopathy in adults
FLUORIDE
Prevents dental caries. Deficiency is seen where people
consume soft water. Excess fluoride cause increase bone
density, calcification of ligaments and tendons, also affects the dental enamel and causes mottling, pitting and pigmentation.
COPPER
DEFICIENCY can cause microcytic hypochromic anemia, neutropenia, retarded growth in children, skeletal rarefaction and dermatosis
Abnormal copper metabolism is seen in wilson’s disease
Deficiency occurs in PEM or prolonged parenteral nutrition
THANK YOU
Clinical finding of vit defiNutrient Clinical Finding
Thiamine Beriberi: neuropathy, muscle weakness and wasting, cardiomegaly, edema, ophthalmoplegia, confabulation
Riboflavin Magenta tongue, angular stomatitis, seborrhea, cheilosis
Niacin Pellagra: pigmented rash of sun-exposed areas, bright red tongue, diarrhea, apathy, memory loss, disorientation
Vitamin B6 Seborrhea, glossitis, convulsions, neuropathy, depression, confusion, microcytic anemia
Folate Megaloblastic anemia, atrophic glossitis, depression, homocysteine
nutrientClinical finding
Vitamin B12 Megaloblastic anemia, loss of vibratory and position sense, abnormal gait, dementia, impotence, loss of bladder and bowel control, homocysteine, methylmalonic acid
Vitamin C Scurvy: petechiae, ecchymosis, coiled hairs, inflamed and bleeding gums, joint effusion, poor wound healing, fatigue
Vitamin A Xerophthalmia, night blindness, Bitot's spots, follicular hyperkeratosis, impaired embryonic development, immune dysfunction
Vitamin D Rickets: skeletal deformation, rachitic rosary, bowed legs; osteomalacia
Vitamin E Peripheral neuropathy, spinocerebellar ataxia, skeletal muscle atrophy, retinopathy
Vitamin K Elevated prothrombin time, bleeding
Element Deficiency Toxicity
Boron No biologic function determined
Developmental defects, male sterility, testicular atrophy
Calcium Reduced bone mass, osteoporosis
Renal insufficiency (milk-alkali syndrome), nephrolithiasis, impaired iron absorption
Copper Anemia, growth retardation, defective keratinization and pigmentation of hair, hypothermia, degenerative changes in aortic elastin, osteopenia, mental deterioration
Nausea, vomiting, diarrhea, hepatic failure, tremor, mental deterioration, hemolytic anemia, renal dysfunction
Chromium Impaired glucose tolerance
Occupational: renal failure, dermatitis, pulmonary cancer
Fluoride Dental caries Dental and skeletal fluorosis, osteosclerosis