Vitamin D
inactive form of vitamin D that is ready for excretion
24,25 dihydroxyvitamin D
what is the storage form of vitamin D
25-OH D3 (calcidiol)
which form is converted to D3 from skin
7 dehydro cholesterol
ergosterol can be converted to
D2
less toxic supplement form of vitamin D: D2 or D3?
D2
vitamin D form present in plants
D2 ergocalciferol
supplement form of vitamin D
D2 or D3
steroid 7 dehydrocholesterol is synthesized in skin and converted to
D3
vitamin D form present in the skin
D3 cholecalciferol
two forms of vitamin D
D3 cholecalciferol D2 ergocalciferol
1,25-dihydroxyvitamin D
OH group added by 1 hydroxylase
24,25-dihydroxyvitamin D
OH group added by 24 hydroxylase
what are some factors that can affect vitamin D3 synthesis in the skin?
ageing degree of skin pigmentation sunscreen
largest storage site of vitamin D
blood
25-hydroxy vitamin D
calcidiol
D3 is converted to ____________________ in the liver
calcidiol
1,25-dihydroxyvitamin D=
calcitriol
active form of vitamin D
calcitriol
main function of vitamin D
calcium absorption
How stable is vitamin D?
can be heated, frozen etc. very stable
precursor of vitamin D
cholesterol
micelles of vit D are incorporated into
chylomicrons
1 a-hydroxylase
enzyme that converts calcidiol to active form of vitamin D in the kidney
plant origin=
ergosterol
animal origins of vitamin D
fatty fish, liver, egg yolk, dairy products
calcitriol made in
kidney
who can synthesize more vitamin D in the skin: lighter or darker skinned people?
lighter skin
calcidiol is made in the
liver
calcidiol made in
liver
vitamin D is absorbed from a
micelle
Vitamin D fortified D products
milk, margarine, some cereals and breads
vitamin D is not found __________________ in many foods
naturally
is vit D essential?
not always
vitamin D form synthesized in the skin and converted to D3
steroid 7 dehydrocholesterol
how long is D3 stored in the liver?
three months
Vitamin D is transported in the blood by
vitamin D binding protein (DBP)
