Feb7 M3-Vitamins and Minerals Flashcards
vitamins def
13 organic molecules that must be consumed in mg doses throughout life
water-soluble and fat-soluble vitamins and how many of each
9 water soluble (vit C and B)
4 fat soluble (A,D,E,K)
nutritionally essential minerals
Fe, Mg, Ca, PO4, zinc, Na, K, Cl
trace elements + examples
less than few mg required for life
iodine, copper, selenium
main cause of vitamin deficiency and other causes
- inadequate consumption
- other: malasoprtion, increased excretion, abnormal loss, catabolism
3 stages of vitamin deficiency diseases
- tissue depletion
- sublinical vitamin deficiency
- specific vitamin deficiency disease
tissue depletion stage def
vitamin levels (tissue stores) are subnormal for metabolic needs
sublinical vitamin deficiency def
- metab functions requiring vitamin are impaired but body adapts and compensate.
- feel fatigue, decreased endurance. increased long-term risk of certain disease
specific vitamin deficency disease def
important metab impairment, non specific and specific symptoms with clinical picture of a specific vitamin deficiency disease
what predisposes people to vitamin deficiency disease
malnutrition, malabsorption or metab disease, anorexia, advanced disease
sources of vitA
certain parts of animals, certain vegetables and fruits (those with carotenoids, especially beta-carotene)
what happens with beta carotene in the body
converted to retinol, one of the 3 forms of vitamin A
what’s retinol
a form of vitamin A essential for vision (bc light sensitive pigments of the retina contain a retinol derivative)
symptom of severe vit A deficiency
night blindness (impaired dark adaptation)
consequences of vitA deficiency
- immunodeficiency, resp disease, diarrhea, infection
- in pregnancy, severefetal malformation
what patients have vit A deficiency most commonly
pts with fat malabsorption (pancreatic insufficiency, chronic biliary obstruction, CF, celiac disease)
what’s unique with vitA
only vitamin that is toxic when consumed in excess
who is given vitA supplements typically
pregnant women
thiamine (vit B1) function
coenzyme function for decarboxylation reactions. + cofactor in pyruvate dehydrogenase
wet vs dry beriberi
wet beriberi = B1 deficiency shows heart failure and edema
dry beriberi= B1 deficiency gives skm atrophy and nerve dysfct
niacin (B3) function
required to synthesize NAD and NADP
end stage disease of niacin deficiency and manifestation
pellagra. rashes, diarrhea, inflammed tongue, mood disturbances
pyridoxine (B6) function
(converted to pyridoxal phosphate) cofactor of many enzymes, including CBS, involved in homocysteine metabolism
pyridoxine deficiency appears how
peripheral neuropathy, psychiatric depression,
when to strongly consider and treat (preventively) B1, B3 and B6 deficiency
- alcoholism
- poor food intake
- chronic starvation
- malabsorption
- chronic vomiting
folate function
folate = family of molecules use to direct methyl (one carbon) groups in the cell to specific metab pathways (including homocysteine remethylation and DNA synthesis)
folate deficiency symptoms (severe)
poor cell turnover (bc of DNA synth fct): GI epithelium BM.
anemia, diarrhea, fetal malformations
sublinical folate deficiency consequence
hyperhomocystinemia, homocystinuria
folic acid in what food and systematically give supplement to who
coloured fruits and vegetables
given to pregnant women
who’s at greater risk of folate deficiency and some people supplemented
alcoholism, poor diet, starvation
supp in hemolytic anemia (poor tunrover)
cobalamin (B12) fct
coenzyme for methionine synthase (makes homocysteine back into met) and another enzyme
2 consequences of B12 deficiency
- hyperhomocystinuria and GI symptoms like folate deficiency
- peripheral neuropathy
how cobalamin (B12) is absorbed
Intrinsic factor produced by parietal cells in the stomach. IF-B12 complex absorbed in ileum
pernicious anemia def
auto-immune destruction of parietal cells (no more IF)
when to consider B12 supp by injection
stomach removed or diseased or absent ileum
mistake to avoid in treating macrocytic anemia (of folate or cobalamin deficiency)
give folate only. MUST give folate AND cobalamin if cobalamin deficiency is present bc otherwise peripheral neuropathy
ascorbic acid (vit C) fct
- reducing agent in hydroxylation rxs
2. required for collagen, NE and E synthesis
end stage disease of vit C deficiency and symptoms
scurvy: fatigue, skin lesions, mood disturbances, gingivitis, joint hemorrhage
people who are commonly vitamin C deficient
alcoholism, poor diet, starvation, malabsorption
cholecalciferol (vit D) active molecule and fct
1,25 dihydroxy vitD (calcitriol). calcium homeostasis, SI, kidney, parathyroid
vit D deficiency in adults vs children
children: rickets (undermineralized bones)
adults: osteomalacia
why vit D deficiency affects brain, muscles and immune cells (risk of prob in all these + possible autoimmune disease)
bc these cells take up 25-OH vit D and make it calcitriol for internal use
who’s at risk for vitD deficiency
not exposed to sunlight, dark skin, fat malabsorption, liver disease, renal disease
essential FAs def and 2 essential
polyunsaturated FAs for PGs and thromboxane synthesis
- omega 6 EFAs needed for arachidonic acid synthesis
- omega 3 EFAs for synth of FAs needed in growth
iron function
binds O2 in Hb. essential in activity of many enzymes too
where’s Fe in the body
two thirds in the blood
one third in bone marrow, spleen, muscles (myoglobin) and liver (ferritin stores it)
most common Fe deficiency disease
iron deficiency anemia
iron deficiency (and iron deficiency anemia) common in what patients + misleading lab test
systemic inflamm. acute phase response causes anemia + hard to see anemia bc plasma ferritin increases
zinc fct and food source
component of many enzymes. meat and flesh are main sources of zinc.
who is more likely to develop zinc deficiency
chronically starving patients, chronic inflammatory diarrhea (inflammatory diarrhea is rich in zinc)
zinc deficiency in adults consequence
ageusia (taste impairment), skin rash, impaired wound healing, immune deficiency
