36. Vitamins Flashcards
What is needed to absorb fat soluble vitamins?
Functioning pancreas
Intestinal cells
Bile salts
What are the functions of vitamin A?
Essential to vision Anti-oxidant Lipid peroxidation Healthy linings of the eyes and respiratory, urinary and intestinal tracts Cell differentiation
What are the functions of vitamin D?
Calcium homeostasis
Mobilisation of calcium
Regulation of bone metabolism
Regulation of gene expression
How is cholesterol converted to calcitriol?
Sunlight converts cholesterol to cholecalciferol
Liver microsomes convert to calcidiol
Kidney converts to calcitriol
What is the active form of vitamin E?
Alpha tocopherol
What are the functions of vitamin E?
Free radical scavenger
Protects PUFAs from peroxidation
Decreases oxidation of LDL
Affects cholesterol metabolism
What are the functions of vitamin K?
Coagulation cascade
Carboxylation of bone protein, osteocalcin
What is primary deficiency of vitamin A?
Prolonged dietary deprivaton
What is secondary deficiency of vitamin A?
Inadequate conversion to active form
What are the symptoms of vitamin A deficiency?
Night blindness Xerophthalmia (dry eyes) Keratomalacia (softening of cornea) Bitot's spots (grey spots in cornea) Dermatological problems Impairment of immune system
What are the causes of a vitamin D deficiency?
Impaired availability
Impaired hydroxylation in liver
Impaired kidney production of calcitriol
What are the results of vitamin D deficiency?
Rickets
Osteomalacia
Osteoporosis
What are the causes of a vitamin E deficiency?
Severe malnutrition
Fat metabolism disorders
Carrier protein or lipoprotein defects
What are the symptoms of a vitamin E deficiency?
Skeletal muscle pain
Degenerative neurological problems
Haemolytic anaemia
What are the causes of vitamin K deficiency?
Common in newborns
Long-term antibiotic use
High doses of vitamin A and E
What are the symptoms of a vitamin K deficiency?
Easy bruising
Mucosal bleeding
Splinter haemorrhages
Black, tar-like stool
What happens as a result of vitamin D hypervitaminosis?
Calcium deposits in tissues, joints, lungs, brain, kidney
Muscle weakness
What happens as a result of acute vitamin A hypervitaminosis?
Vomiting, vertigo, blurry vision
What happens as a result of chronic vitamin A hypervitaminosis?
Hyperlipidaemia, hepatotoxicity
What happens as a result of teratogenic vitamin A hypervitaminosis?
Spontaneous loss of foetus
What happens as a result of vitamin E hypervitaminosis?
Fatigue, headache, impaired blood coagulation
What is the other name for vitamin B1?
Thiamine
What is the other name for vitamin B2?
Riboflavin
What is the other name for vitamin B3?
Niacin
What is the other name for vitamin B5?
Pantothenic acid
What is the other name for vitamin B6?
Pyroxidine
What is the other name for vitamin B7?
Biotin
What is the other name for vitamin B9?
Folate
What is the other name for vitamin B12?
Cobalamin
What is the function of thiamine?
Conversion of pyruvate to acetyl CoA in Kreb’s cycle
What is the function of riboflavin?
Constituent of riboflavin 5’-phosphate and flavin adenine dinucleotide
What is the function of niacin?
Forms coenzymes NAD and NADP
What is the function of pantothenic acid?
Synthesises CoA
Metabolism of carbs, fat and protein
What is the function of pyroxidine?
Synthesis and catabolism of amino acids
Cofactor for glycogen phosphorylase
What is the function of biotin?
Attached at active site of carboxylases
What is the function of folate?
Coenzyme in single carbon transfer reactions
Biological methylation reactions
Makes methionine from homocysteine
What is the function of cobalamin?
Cofactor for methionine synthase
Synthesis of succinyl CoA
What are the functions of vitamin C?
Antioxidant Synthesis of succinyl CoA Cofactor for carnitine synthesis Cofactor for serotonin and norepinephrine synthesis Enhances iron absorption
B1 deficiency
Berberi
Wernicke-Korsakoff syndrome
Alcoholics
B2 deficiency
Cheliosis (inflammation of the lips) Angular stomatitis Magenta tongue Dry, scaly skin Decreased RBCs
B3 deficiency
Slow metabolism
Pellegra
B5 deficiency
Numbness
Tingling in hands and feet
Vomiting and fatigue
B6 deficiency
Dermatitis Glossitis Convulsions Microcytic hypochromic anaemia Alcoholics
B7 deficiency
Scaly red rash around eyes, nose, mouth, genitals
Depression
Numbness and tingling in extremities
Defects in metabolism of fatty acid chains
B9 deficiency
Megaloblastic anaemia
Increased plasma homocysteine
Hypersegmented neutrophils
Low birth weight and neural tube defects
B12 deficiency
Increased homocysteine
Megaloblastic anaemia
Dehydration and nerve cell death
Skin hypersensitivity
Vitamin C deficiency
Scurvy Weakness and joint swelling Superficial bleeding Depression Vasomotor instability
What happens with excess vitamin C?
Diarrhoea
Abdominal bloating
Risk of calcium oxalate stones
Cardiac arrhythmias