Vitamins, Micronutrients, and Deficiencies

Question 1

How many vitamins are necessary for health? How many are fat soluble?

Answer 1

• 13 vitamins are needed

- 4 are fat soluble (A, D, E, K); the rest are water soluble (B1, B2, B3, B5, B6, B7, B9, B12, C)

Question 2

Which two vitamins can be synthesized endogenously?

Answer 2

• vitamins D and K
• vit D can be made via UV exposure
• vit k can be made from colonic biota

Question 3

Vitamin A

Answer 3

• retinol
• function: constituent of visual pigments; essential for differentiation of epithelial cells into specialized tissue; antioxidant
• source: animal-derived foods and veggies

Question 4

Vitamin A Deficiency

Answer 4

• nyctalopia (night blindness); impaired vision; keratomalacia (corneal degeneration); dry, scaly skin and eyes; immune suppression

Question 5

Vitamin D

Answer 5

• function: increases intestinal absorption of calcium and phosphate; increases bone mineralization/formation
• source: endogenous synthesis via UV exposure; milk; plants

Question 6

Vitamin D Deficiency

Answer 6

• rickets in children and osteomalacia in adults due to excess unmineralized bone matrix leading to weakness

Question 7

Vitamin C

Answer 7

• ascorbic acid
• function: necessary for collagen synthesis; necessary for synthesis of NE; facilitates iron absorption via reduction; antioxidant
• source: fruits and veggies

Question 8

Vitamin C Deficiency

Answer 8

• scurvy: bone disease in growing children, hemorrhaging and healing defects, swollen and bleeding gums, bruising, anemia, “corkscrew hair”
• immune suppression

Question 9

What binds vitamin B12 (for protection) in the stomach before intrinsic factor? How do vitamin B12-intrinsic factor complexes get absorbed?

Answer 9

• haptocorrin

- they get absorbed in the terminal ileum via specific cubulin receptors

Question 10

What pathology results with a thiamine deficiency? A B12 deficiency? A folate deficiency?

Answer 10

• thiamine: beri-beri, Wernicke-Korsakoff syndrome (WKS)
• B12: pernicious anemia
• folate: macrocytic anemia

Question 11

Vitamin K

Answer 11

• function: cofactor for the gamma-carboxylation of glutamic acid residues on coagulation factors II, XII, IX, and X, and proteins C and S

Question 12

Iodine

Answer 12

• needed for thyroid hormones

- (thyroid stores 85% of the body’s iodine)