Flashcards in Micronutrients II - Vitamins Deck (93)
typically cofactors for enzymes
organic compounds required for diet in only small amounts to maintain fundamental cell functions
Which vitamins are most utilized in energy metabolism?
how many water soluble vitamins?
how many lipid soluble vitamins?
in phospholipids, methyl donor
choline free diet could lead to liver damage
not a vitamin but required for pyruvate decarboxylase
animals can make this
redox cofactor for quinoproteins
ex: flavoproteins - dehydrogenases
Vitamin D only needed when
sunlight is absent
lack of adequate intake in diet
causes of Primary deficiency
poor nutrition/food habits, poverty, ignorance of nutrition needs, insufficient food, lack of proper vitamin rich foods, food fads, food taboos, vitamin destruction, anorexia
poor availability or utilization of a vitamin due to environmental or physiological conditions
Causes of secondary deficiency
poor digestions (achlorhydria-low gastric acid)
malabsorption (diarrhea, infections)
impaired utilization (drug therapy)
Vitamin deficiencies significant in
any pt with digestion/malabsorption problems
chronic substance abuse (alcohol) bad diet & inhibits uptake of vit
recent surgery, total parenteral nutrition
elderly, pregnant/breastfeeding, smokers, alcoholics, diabetics
risk thiamine deficiency with high CHO diet
What aids in fat soluble vitamin absorption?
digestive enzymes from pancreas help uptake
Bacteria in the gut make small amount of
vitamin K, B12, and biotin
Fat soluble vitamins are absorbed with
where are fat soluble vitamins stored?
liver and nonspecifically adipose tissue
Risk of toxicity with what vitamin?
mixture of Retinoids
role in gene regulation - reproduction, embryogenesis, development, cell differentiation and proliferation) vision, maintenance of brain function and skin
Vitamin A deficiency
Vitamin A Excess
birth defects, (tetratogenic), blurred vision, liver damage
Vitamin A is derived from
-three forms - alcohol, aldehyde and acid
Find Vitamin A in
green, leafy vegetables
organ meat - liver
Why is beta carotene a safer source?
conversion to Vit A in gut decreases as dose increases
Absorption depends on type of food and how much fat is also in diet
How is Vitamin A taken up?
Retinol and carotenoids bound in enterocyte to Carotene binding proteins
carried in blood by chylomicrons or albumin
How is vitamin A important for vision?
combines with opsin to form rhodoposin in rod and cone cells
impt for the shape and structure of the conjunctiva and the cornea as well
functions in cellular differentiation - RXR and RAR receptors