Fat soluble Vitamins

Question 1

Biochemical function of Vitamin A

Answer 1

Photochemical for vision
retinal signaling
Maintenance of conjunctiva and cornea

Question 2

Major dietary sources of Vitamin A

Answer 2

Preformed retinyl palmitate from animal sources
Liver, dairy, egg yolk, fish oil
Beta-carotene

Question 3

Deficiency findings of Vitamin A

Answer 3

EYES: xerophthalmia (corneal dryness) Bitot’s Spots, night blindness, total blindness
EPITHELIUM: linings flat, dry, and keratinized
Immune Impairment: Vit A treatment with measles reduces morbidity and mortality

Question 4

circumstances at risk for deficiency of Vitamin A

Answer 4

Low Vit A intake- Autism
Fat malabsorption
Protein Malnutrition

Question 5

circumstances at risk for toxicity of Vitamin A

Answer 5

Only with preformed Vit A (retinyl palmitate)
Vomiting, increased ICP, headache, bone pain, osteopenia/porosis
liver damage hepatitis, fibrosis, failure, death
birth defects e.g. isotretinoin (Accutane)

Question 6

Biochemical function of Vitamin D

Answer 6

Maintains intra/extracellular Ca++
Intestinal absorption Ca and Phos, renal reabsorption, and mobilization from bone
Immune function – Innate: antimicrobial peptide generation (cathelicidin and defensins) in macrophages
Adaptive: modulation of cytokines
Regulates cell growth and differentiation

Question 7

Major dietary sources of Vitamin D

Answer 7

Conversion in skin
UVB light, Dehydrocholesterol, Cholecalciferol D3 in skin 
Dietary
Fish liver oils, fatty fish, egg yolks
Fortified milk and formula
Sources
Plant algae, yeast+UV =D2 ergocalciferol
Animal D3 cholecalciferol, more potent? larger AUC than D2, similar peak plasma 25OH

Question 8

Vitamin D Absorbed

Answer 8

Absorbed in chylomicrons.

Hydroxyls added in liver and kidney

Question 9

Deficiency findings of Vitamin D

Answer 9

Childhood rickets -

Question 10

circumstances at risk for deficiency of Vitamin D

Answer 10

Low Sun exposure (NE winter)
Dark Pigmentation
Low dietary intake
Fat Malabsorption
Breastfed Infant  supplement
Obesity 
Fat sequestration, sedentary
Liver or Renal Disease (X-OH)
Need Calcitriol Rx supplementation

Question 11

circumstances at risk for toxicity of Vitamin D

Answer 11

Findings
Hypercalcemia, Vomiting, seizures, nephrocalcinosis, vascular and soft tissue calcinosis
Risk
Sarcoidosis (granulomas activate D)
>10,000 IU/d for wks in child or during pregnancy
50-100,000 IU daily in adult >3wks

Question 12

Biochemical function of Vitamin E

Answer 12

antioxidant, scavenges free radicals, stabilizes cell membranes

Question 13

Major dietary sources of Vitamin E

Answer 13

Polyunsaturated fat rich vegetable oils (e.g. sunflower), corn, nuts, wheat germ

Question 14

Deficiency findings of Vitamin E

Answer 14

Neurologic Degeneration IRREVERSIBLE

Hemolytic Anemia

Question 15

circumstances at risk for deficiency of Vitamin E

Answer 15

malnurishment
prematurity
fat malbsorption /
short gut

Question 16

toxicity of Vitamin E

Answer 16

Coagulopathy

Very large doses inhibit Vit K dependent clotting factors

Question 17

Biochemical function of Vitamin K

Answer 17

Carboxylation of clotting factors

Question 18

Major dietary sources of Vitamin K

Answer 18

leafy greens, brocolli, fruits, seeds, beef liver

Synthesis by Intestinal Bacteria

Question 19

circumstances at risk for deficiency of Vitamin K

Answer 19

Newborns – poor placental transport
2-12 wks breastfed untreated
Fat Malabsorption
Chronic Antibiotics

Question 20

Deficiency findings of Vitamin K

Answer 20

prolonged coagulation time
Hemorrhagic disease of the newborn
Purpura, GI bleeds, CNS bleeds