Unit 2 - Vitamins/minerals & nutrition Flashcards
what are the essential components of diet?
carbohydrates proteins lipids minerals vitamins water
give source and function of iron
source: red meat
function: synthesis of cytochromes/ haemoglobin/ aerobic respiration
what is the effect of iron deficiency + overload?
deficiency: anaemia - cannot produce haemoglobin - low O2- tired/shortness of breath
overload: haemochromatosis - oxidative/ liver damage
how is iron regulated?
bound to transferrin and regulated by hepcidin
-erythroid factors inhibit hepcidin - more iron recycling
give sources and functions of calcium
sources: dairy
functions: bones/ teeth/ muscles/ blood clotting
what is the effect of deficiency + overload of calcium?
deficiency: hypocalcaemia- tooth decay/ osteoporosis/ dry nails
overload: disordered activation of enzymes
give sources and functions of magnesium - deficiency/overload conditions
sources: green leafy veg/ pumpkin seeds/ nuts
functions: co-factor in protein synthesis/ muscle relaxation/ PTH function
deficiency: muscle cramps
overload: diarrhoea
give sources and functions of phosphorus and condition of deficiency
sources: red meats/ fish
functions: strong bones/ teeth
deficiency: rickets/ osteoporosis
give sources, functions of iodine and condition of deficiency
sources: white fish/ shellfish
functions: synthesis of thyroid hormones
deficiency: enlargement of thyroid glands
give sources, functions of zinc and condition of deficiency
sources: meat/ shellfish
functions: wound healing/ processing carbohydrates/ erythropoiesis
deficiency: hair loss/ poor wound healing/ diarrhoea
give sources, functions of copper and condition of deficiency
sources: nuts/ shellfish
functions: erythropoiesis/ haemoglobin formation
deficiency: growth failure/ anaemia
(menkes disease)
which vitamins are fat soluble and which are water soluble?
A, D, E, K - fat soluble
B&C - water soluble
how are these vitamins absorbed in the body?
fat-soluble vitamins absorbed in the same way as lipids
water soluble vitamins use sodium dependent carriers
which vitamin is the exception in terms of absorption?
vitamin B12 - cobalamin
= released due to low pH of gastric juice
- binds to haptocorrin which protects it in the stomach but is degraded in the duodenum
- free B12 binds with intrinsic factor - the B12: IF complex is recognised by cubulin = receptor in brush border membrane and is absorbed by enterocytes in the lower ileum
complex transported to basolateral membrane and binds to transcobalamin II bfore entering capillaries for further protection
give the sources, functions and condition of deficiency of B12
sources: microbes - cheese, beer
functions: red blood cell formation
deficiency -anaemia which can compensated for by folic acid
give the sources, functions and condition of deficiency of B9
B9 - folic acid
sources: broccoli, leafy green veg
functions: RNA/ DNA synthesis
deficiency: spinal bifida = neural tube defects/ folate deficiency anaemia
give the sources, functions and condition of deficiency of B6
B6- pyridoxine
source: whole grains
functions: neurotransmitter synthesis
deficiency: neurological issues
give the sources, function of B5
B5 - pantothenic acid
sources: all meats and veg
functions: essential part of co-enzyme A
deficiency only occurs with victims of starvation
give the sources, functions and condition of deficiency of B3
B3 - niacin
sources: meat/ fish/ wheat flour
function: constituent of NAD/ NADP
deficiency: pellagra: dementia, diarrhoea and dermatitis
overload: liver damage
give the sources, functions and condition of deficiency of B1
B1- thiamin
sources: breakfast cereals
function: co-enzyme TPP for link reaction
deficiency: beriberi disease
give the sources, functions and condition of deficiency of vitamin C
ascorbic acid
sources: oranges
functions: collagen synthesis/ carnitine synthesis
deficiency: scurvy
give the sources, functions and condition of deficiency of vitamin A
provitamin - carotenoids converted to retinol in small intestine`
sources: liver/ oily fish/ dairy - milk/ cheese/ eggs
functions: formation of epithelia/ mucous membranes/ rhodopsin
deficiency: blindness
excess: toxic
how is vitamin D produced?
D3 from animals - produced using UV light -7-dehydrocholesterol converted into 25, hydroxycholecalciferol (by 25-hydroxylase in liver) and then kidneys converts to its active form 1,25-dihydroxycholecalciferol (using 1-hydroxylase)
D2 from plants
what is the recommended intake of vitamin D if pregnant and breastfeeding?
10 micrograms per day
what is vitamin D role in calcium homeostasis?
decrease in plasma calcium is detected then levels of PTH increase which increases kidney production of vitamin D which increases plasma levels of 1,25 vitamin D so increases intestinal calcium absorption to increase levels of plasm calcium
how else does PTH affect calcium homeostasis?
causes increase in bone calcium resorption so calcium released into plasma
give the sources and functions of vitamin E
source: nuts, seeds, oil
functions: antioxidant, electron transfer, protects cell membrane from free radicals
what is the effect of deficiency + overload of Vitamin E?
deficiency: muscle weakness, weak nerve impulses
overload: blurry vision
give the sources and functions of vitamin K?
source: green leafy veg
functions: synthesis of prothrombin - haemostasis
+ clotting factors 2, 7, 9, 10
