vitamin D

Question 1

Skin cancer is the most common form of cancer in the United States

Answer 1

true

Question 2

why has photoprotection become contreversial?

Answer 2

We cannot protect the skin from the damaging effects of UVR without decreasing the formation of Vitamin D

Question 3

UV action spectra for DNA damage, skin cancer and vitamin D photosynthesis is i________

Answer 3

identical

Question 4

who is at risk for vit D deficiency? (DONE)

Answer 4

dark skin obesity northern latitudes obese

Question 5

which form of vitamin D is used to determine a patient’s vitamin D status?

Answer 5

25-hydroxy vitamin D3

Question 6

what is the right level of Vitamin D? levels for deficiency? insufficiency, sufficiency, and intoxication?

Answer 6

deficiency: <20ng/ml

insufficiency: 21-29 ng/ml

**sufficiency: >30ng/mL **

intoxication: >150 ng/mL

Question 7

what are two sources of vitamin D we should be aware of?

Answer 7

Sunlight Most people get vitamin D from sun exposure

Diet Only

naturally occurring food that supplies substantial quantities of the vitamin is cold-water ocean fish Fortified foods (milk, OJ etc.) Vitamins

Question 8

who is usually vitamin D deficienct?

Answer 8

Despite food fortification, deficiency remains common in children and adults with limited sun exposure

Question 9

what is primary cause of low vit D status?

Answer 9

Decreased skin synthesis of vitamin D is widely accepted as primary cause of epidemic low vitamin D status worldwide

Question 10

causes of reduced skin synthesis of vitamin D? (7)

Answer 10

season and latitude

skin pigment

aging

sunscreen and photoprotection

decreased bioavailability

heritable and acquired disorders

decreased synthesis

Question 11

how does season and latitude reduce vit D synthesis?

Answer 11

Ozone filters out sunlight increases the amount of ozone UVB needs to passalmost all of UVB
Lower angle of incoming through to reach the earths surface
Very little if any vitamin D can be synthesized in the skin from November through February at latitudes north of 37 degrees

Question 12

how does skin pigment reduce vit D synthesis?

Answer 12

Absorption of UVB by melanin reduces vitamin D synthesis by as much as 99%

Question 13

how does aging reduce vit D synthesis?

Answer 13

Reduction of 7-dehydrocholesterol in the skin Reduces vitamin D synthesis by about 75% in a 70-year old

Question 14

how do sunscreen and photoprotection reduce vit D synthesis ?

Answer 14

SPF 15 reduces vitamin D synthesis by 93% (if used correctly…)

Question 15

how does decreased bioavailability reduce vit D synthesis?

Answer 15

Malabsorption Reduced fat absorption Obesity Vitamin D sequestered in body fat

Question 16

decreased synthesis of vit D absorption?

Answer 16

Liver disease Renal disease

Question 17

how does Vit D work? remember (PAAD)

Answer 17

Fat-soluble steroid hormone Exerts its biologic effects by binding to vitamin D specific receptors Found in most tissues and cells in the body Controls over 200 different genes Proliferation Differentiation Apoptosis Angiogenesis

Question 18

vitamin D and PTH?

Answer 18

Acts with PTH to maintain normal levels of calcium and phosphate (increases intestinal absorption of Ca+, PO4, and Mg) -osteolytic effect on bone -decreased renal clearance

Question 19

what is rickets? how is it treated?

Answer 19

Extreme and prolonged vitamin D deficiency Softening and weakening of bones Marked bending of bones, fractures, costochondral swelling tx:Conquered with food fortification

Question 20

what are the manifestations of vitamin D deficiency?

Answer 20

Adults: Osteomalacia, Osteopenia, Osteoporosis(increased risk of fractures) Muscle weakness - increase risk of falls

Question 21

individuals at higher latitudes are at increased risk for? (POP BLC)

Answer 21

Increased risk for lymphoma, colon, pancreatic, prostate, ovarian, breast and other cancers More likely to die from these cancers

Question 22

Individuals with 25-hydroxyvitamin D levels below 20 ng/ml are at increased risk for___________?

Answer 22

30 to 50% increased risk of colon, prostate and breast cancer Higher mortality from these cancers

Question 23

what are some diseases that may be more common at high altitudes?

Answer 23

Cardiovascular disease Hypertension, CHF Schizophrenia Depression Wheezing illnesses Autoimmune disease Diabetes, Crohn’s disease, rheumatoid arthritis, multiple sclerosis

Question 24

t/fVitamin D obtained from the diet or supplements can fully substitute for vitamin D synthesized in the skin

Answer 24

t

Question 25

KNOW: what are the two forms of vitamin D? which one is more readily absorbed?

Answer 25

Vitamin D2 (ergocalciferol - plant derived)

Vitamin D3 (cholecalciferol – fish derived)

Vitamin D3 is more readily absorbed than D2 More effective at maintaining serum 25-hydroxyvitamin D levels

Question 26

above what level (ng/mL) is vitamin D toxic? what can too much vit D cause? how common is vit D toxication?

Answer 26

Serum 25-hydroxyvitamin D level above 150ng/ml

Hypercalcemia, hyperphosphatemia and/or metastatic calcification

Rare but may be caused by ingestion of excessively high doses of vitamin D

Question 27

how much vit D would you have to consume for Vit D intoxication?

Answer 27

More than 50,000 IU per day

Question 28

t/f. Doses of 10,000 IU of vitamin D3 per day for up to 5 months does not cause toxicity

Answer 28

true

Question 29

KNOW: Excessive exposure to ultraviolet light will increase risk of __________

Answer 29

Excessive exposure to ultraviolet light will increase risk of skin cancer

Question 30

KNOW: what is required for vit D synthesis in the skin?

Answer 30

UVL is required for vitamin D synthesis in the skin

Question 31

KNOW: who is at most risk for vit D deficiency?

Answer 31

Individuals with limited exposure to UVL are at higher risk for vitamin D deficiency

Question 32

which metabolic conditions and diseases are associated with vit D deficiency?

Answer 32

**Abnormal calcium and phosphorus metabolism: rickets, osteoporosis **

Possibly other diseases: cancer, diabetes, immune system

Question 33

KNOW: how can ppl obtain vitamin D? what should you do with individuals at risk for vit D deficiency?

Answer 33

Vitamin D obtained from diet or supplements can fully substitute for vitamin D synthesized in skin

People can obtain ample vitamin D from a combination of diet, supplements, and incidental protected sun exposure

Individuals at risk for vitamin D deficiency due to decreased photosynthesis should receive vitamin D supplementation

Question 34

t/f. you Continue to recommend photoprotection to prevent skin cancer.

Answer 34

TRUE

Question 35

KNOW: who are lower risk vit D patients and how much vit D/day should they receive?

Answer 35

Lower risk patients
400 IU daily for infants
600 IU daily for children and adults
800 IU daily for elderly

Question 36

KNOW: who are higher risk vit D patients? what should you consider doing?

Answer 36

Higher risk patients
Homebound, northern latitudes, winter, obesity, darker skin
Consider getting a vitamin D level

Question 37

what is the active form of vitamid D?

Answer 37

1, 25 vitamin D3