Vitamins

Question 1

what are vitamins?

Answer 1

Vitamins are organic molecules essential to human metabolic and cellular function that cannot be produced (or in sufficient quantities) within the body and must be obtained through external sources, often the diet.

Question 2

vitamins can act as ___ cofactors

Answer 2

metabolic

Question 3

vitamins act as precursors for ___

Answer 3

specialized cellular molecules

Question 4

vitamin deficiency leads to ___

Answer 4

severe health problems; deficiencies are rare in western countries

Question 5

T or F:

vitamin toxicity may occur with excessive consumption of certian vitamins

Answer 5

true

Question 6

what are the 4 fat soluble essential vitamins? which ones can cause toxicity?

Answer 6

• vitamin A, D, E, and K
• vit. A and D can be toxic

Question 7

decribe fat-soluble vitamins

Answer 7

• fatty acyl chains
• ingested as esters
• require cholesterol esterase for uptake
• integrated into micelles and chylomicrons
• chronic and subacute toxicity

Question 8

what are the 9 essential water soluble vitamins? which ones can be toxic?

Answer 8

• vitamins B1, B2, B3, B5, B6, B7, B9, B12, and C
• vit. B3, B6, and C can be toxic

Question 9

describe water-soluble vitamins

Answer 9

• acute use
• urinary excretion
• little toxicity
• only vitamin B12 is stored for long periods
• absorbed by Na+ cotransporters, except B9 and B12

Question 10

what are vitamers?

Answer 10

• compounds grouped under the umbrella of a single vitamin
• vitamers are often structurally similar, related, and may be converted

Question 11

what is the general function of vitamin A?

Answer 11

required for normal vision, adaptive immunity, bone growth, and cell membrane stability

Question 12

what is the general function of vitamin B1? what do chronic vit B1 deficiencies cause?

Answer 12

• aka thiamine
• function: essential coenzyme
• chronic deficiencies can cause beriberi and/or wernicke-korsakoff syndrome

Question 13

what is the general function of B2?

Answer 13

• aka riboflavin
• essential for carbohydrate and lipid metabolism

Question 14

what is the general function of vitamin B3? what is caused by a deficiency?

Answer 14

• aka niacin
• necessary for NAD+
• deficiency can cause pellagra

Question 15

what is the general funciton of vitamin B5?

Answer 15

• aka patothenic acid
• major component in coenzyme A synthesis

Question 16

what is the major funciton of vitamin B6?

Answer 16

• aka pyridoxine
• necessary for neurotransmitter synthesis, and function as coenzymes

Question 17

what is the general function of vitamin B7?

Answer 17

• aka biotin
• cofactor for carboxylases involved in energy production, fatty acid synthesis, and amino acid catabolism

Question 18

what is the general function of vitamin B9? what are the daily adequate intakes?

Answer 18

• aka folate
• essential for amino acid metabolism
• 400 micrograms/day DFE for adults, 600 micrograms/day FE for pregnant women

Question 19

what is the general function of vitamin B12?

Answer 19

• aka cobalamins
• cofactor for fatty acid synthesis

Question 20

what is the general function of vitamin C? what does a deficiency cause?

Answer 20

• antioxidant
• deficiency can cause scurvy

Question 21

what is the general function of vitamin D? what can a deficiency cause?

Answer 21

• control of calcium and phosphate metabolism and integration into bone
• deficiency can cause rickets

Question 22

what is the general function of vitamin E?

Answer 22

• antioxidant that protects against LDL oxidation

Question 23

what is the general funciton of vitamin K?

Answer 23

required for the produciton of clotting factors and the carboxylation of osteocalcin in bone

Question 24

what are the 13 essential vitamins?

Answer 24

• vit A
• vit B1, B2, B3, B5, B6, B7, B9, B12
• vit C
• vit D
• vit E
• vit K