nicotaminamide, but not nicotinic acid, is the form required for the synthesis of
nicotinamide adenine dinucleotide
false
how are the recommended intakes of niacin expressed? (units)
niacin equivalents (mgs)
bioavailability of biotin is near 0% from wheat
true
intake of raw egg white may cause deficiency of
biotin
which of the following is one of the main functions of vitamin B6
transamination
methionine cycle requires
all of the above (B6, B12, folate, niacin)
which anemia is related to folate deficiency?
megaloblastic anemia
to protect against birth defects, a higher RDA of folic acid has been suggested for
pregnant women
true
vitamin B12 is only available from ___________ products
animal
why is the RDA of vitamin B12 so low?
A, B, and C (in the liver free cobalamin can be stored for years, little B12 in the body is
degraded, whole body turnover is about 0.1% daily)
high dietary folate may cure megaloblastic anemia caused by:
both A and B (folate deficiency, B12 deficiency)
formation of retinol from B-carotene requires the presence of what B vitamin?
niacin
dietary fat is not very important regarding the digestion and absorption of pre-
and provitamin A forms
false
within the nucleus, retinoic acid binds to ______________
retinoid X receptors
what is the principle transport vehicle for vitamin E in the blood?
lipoproteins
Which mechanism has been proposed but not proven as vitamin E's principle
function against chronic disease prevention?
anti-oxidation
for which vitamin is the tolerable upper limit set because of increased tendency
for bleeding?
vitamin E (because high doses of vitamin E increase the risk of bleeding)
what is the chemical name for vitamin K in green plants?
phylloquinone
as a coenzyme, vitamin K is required in the carboxylation of Gla proteins by
converting glutamate residues to gamma-carboxyglutamate residues