Vitamin D, E, K

Front 1

where is vitamin D synthesized in the body

Back 1

skin when exposed to sunlight from UV-B radiation

Front 2

what else can vitamin D act as

Back 2

a hormone (made in one place in body, acts in another place in the body)

Front 3

what is vitamin D3 formed from

Back 3

formed in skin from a cholestrol precursor

Front 4

what does sunlight do in vitamin D synthesis

Back 4

changes 7-dehydrocholesterol to cholecalciferol

Front 5

where does vitamin D travel

Back 5

liver and then kidneys, then converted to bioactive form through two steps (adding OH groups)

Front 6

requirements for vitamin D synthesis

Back 6

sunlight 2-3 times/week for 10-15 minutes

Front 7

what causes reduction in D3 production

Back 7

age (75% down by age 70) and skin pigmentation; SPF 8 or higher prevents vitamin D3 production, northern climates (no synthesis in winter)

Front 8

what foods are vitamin D3 and D2 found in

Back 8

fatty fish, cod liver oil, fortified dairy products, some fortified breakfast cereals or supplements

Front 9

what is the RDA for vitamin D based on

Back 9

getting no exposure to sunlight

Front 10

is vitamin D3 and D2 active

Back 10

no but is a provitamin

Front 11

what converts vitamin D

Back 11

liver to 25 OH; still not active here; levels can be measured in blood; 15 day half life

Front 12

which organ converts vitamin D to be active

Back 12

kidneys; calcitrol; 15 hour half life; can't measure accurately; quickly used

Front 13

where is vitamin D excreted

Back 13

bile

Front 14

calcium and vitamin D

Back 14

parathyroid glands respond to a shortage of calcium in the blood by producing PTH

Front 15

PTH

Back 15

stimulates the kidney to produce 1, 25-OH vitamin D

Front 16

what does active vitamin do to calcium

Back 16

^ in D --> ^ calcium absorption in the SI

Front 17

calcitonin

Back 17

acts as a hormone; activated when blood Ca levels rise; stops PTH, decreasing amount of active vitamin D produced; prevents blood Ca from rising too high

Front 18

rickets

Back 18

in children; inadequate mineralization (Ca, P) of bone; bowed legs; enlargement of ends of long bones

Front 19

osteomalacia

Back 19

in adults; softening of bones; impaired bone re-mineralization;softening of the bone; bending of spine; often occurs in women (and those with multiple pregnancies); elderly; reduces vitamin D synthesis

Front 20

what happens during vitamin D deficiency

Back 20

very little calcium is absorbed; despite normal Ca intake, not enough is absorbed and bones are undersupplied

Front 21

vitamin D toxicity

Back 21

comes from excess supplemention; hypercalcemia-->calcium deposits in soft tissue; kidney stones (Ca deposits);hardening of blood vessels

Front 22

what are the forms of Vitamin E

Back 22

tocopherols and tocotrienols;alpha tocopherol is most active

Front 23

sources of vitamin E

Back 23

plant oils, whole grains; (animal fats and dairy have very little)

Front 24

storage or vitamin E

Back 24

90% stored in adipose tissue (not much in liver)

Front 25

vitamin E function

Back 25

antioxidant; controls free radicals, stops free radical chain reactions from propagating; protects phospholipids in cell membranes from damage, protects DNA from damage; vitamin C is needed to regenerate this after it is oxidized by a free radical

Front 26

vitamin E deficiencies

Back 26

hemolytic anemia; immune function impairment; neurological changes in spinal cord and peripheral nervous system

Front 27

hemolytic anemia

Back 27

rare in humans; premature breakdown or red blood cells (hemolysis)

Front 28

vitamin E toxicity

Back 28

relatively nontoxic; at high doese can interfere with vitamin K (and affect blood clotting)

Front 29

vitamin K1

Back 29

phylloquinones

Front 30

what is K1 found in

Back 30

green leafy veggies, broccoli, peas, green beans, biologically active; main dietary form

Front 31

vitamin K2

Back 31

menaquinones

Front 32

what is K2 found in

Back 32

fish oils and meats; yogurt and fermented foods; some synthesized by bacteria in our colon

Front 33

functions of vitamin K

Back 33

synthesis of blood clotting factors by liver; conversion of pre-prothrombin to prothromin (clotting factor); vitamin K must be reactivated once used); bone metabolism: converts K dependent protein to Gla protein-able to bind calcium

Front 34

vitamin K deficiencies

Back 34

very rare; newborns are given K injections within 6 hrs after delivery; long-term antibiotic use can interfere with K synthesis by colon bacteria; impaired fat malabsorption can cause deficiencies; megadose vit A and E can affect K absorption

Front 35

toxicity of K

Back 35

none

Front 36

K and anticoagulants

Back 36

people on these need to have a relatively constant amount od K in their diet (arger amounts make the anticoagulant less effective--more likely to clot)