NUSCTX 10, Midterm 2 - UC Berkeley UPDATED ACTUAL
Questions and CORRECT Answers
Fat-Soluble Vitamins Vitamin A
Vitamin D
Vitamin E
Vitamin K
Water-Soluble Vitamins B complex plus vitamin C
Required in diet
Act as enzyme cofactors
Deficiencies used to be common
People on poor diets often deficient in multiple vitamins
B Vitamins Thiamin (B1)
Riboflavin (B2)
Niacin (B3)
Biotin
Pantothenic Acid
Vitamin B6
Folate
Vitamin B12
Dietary Reference Intakes Adequate Intake
Tolerable Upper-Intake Level
Estimated Average Requirement
Recommended Dietary Allowance
Properties of Water Soluble Vitamins Dissolve in water
No real stores
Readily excreted
Function: coenzymes and antioxidants
Absorbed by portal system
Not required daily
High doses can be toxic
Subject to cooking and food storage losses
Properties of Fat Soluble Vitamins Fat soluble
Stored in tissues
Remain in adipose and liver
Function: hormones, blood clotting, antioxidants
Absorbed by lymphatic system with fats (chylomicrons)
Not required daily
High doses can be toxic
, Digestion of fat soluble vitamins Require bile acids for absorption
Require digestive enzymes for absorption
Absorbed in the similar manner of fats
Little vitamin K production by gut bacteria
Retinol Vitamin A
Retinal Visual Cycle
Retinoids Support development, growth, reproduction
Epithelia (skin, respiratory, and digestive systems)
Immune System
Nervous System
Vitamin A in the Liver Liver breaks down some vitamin A into retinoic acid and saves the rest for storage
Retinoic Acid Reproduction
Nervous System
Epithelia (skin)
Immune Function
Recommended Dietary Allowance of Vitamin A 0.3 mg to 1.3 mg: age, sex, pregnancy, lactation
Toxic Intake 100 fold > RDA in adults
20 fold > in children
Vitamin K Koagulation
Mechanism of Vitamin K Action i) Targeted Protein (e.g. prothrombin)
ii) Vitamin K-dependent enzyme
iii) Modified Protein Binds Ca++(e.g. thrombin)
Vitamin K-Dependent Enzymes Activate specific target proteins by enabling them to bind to calcium.
Vitamin K Functions Essential for activating proteins required for:
Blood clotting
Blood vessel repair
Bone density
Preventing soft-tissue calcification
Warfarin A vitamin K antagonist that retards blood coagulation
Questions and CORRECT Answers
Fat-Soluble Vitamins Vitamin A
Vitamin D
Vitamin E
Vitamin K
Water-Soluble Vitamins B complex plus vitamin C
Required in diet
Act as enzyme cofactors
Deficiencies used to be common
People on poor diets often deficient in multiple vitamins
B Vitamins Thiamin (B1)
Riboflavin (B2)
Niacin (B3)
Biotin
Pantothenic Acid
Vitamin B6
Folate
Vitamin B12
Dietary Reference Intakes Adequate Intake
Tolerable Upper-Intake Level
Estimated Average Requirement
Recommended Dietary Allowance
Properties of Water Soluble Vitamins Dissolve in water
No real stores
Readily excreted
Function: coenzymes and antioxidants
Absorbed by portal system
Not required daily
High doses can be toxic
Subject to cooking and food storage losses
Properties of Fat Soluble Vitamins Fat soluble
Stored in tissues
Remain in adipose and liver
Function: hormones, blood clotting, antioxidants
Absorbed by lymphatic system with fats (chylomicrons)
Not required daily
High doses can be toxic
, Digestion of fat soluble vitamins Require bile acids for absorption
Require digestive enzymes for absorption
Absorbed in the similar manner of fats
Little vitamin K production by gut bacteria
Retinol Vitamin A
Retinal Visual Cycle
Retinoids Support development, growth, reproduction
Epithelia (skin, respiratory, and digestive systems)
Immune System
Nervous System
Vitamin A in the Liver Liver breaks down some vitamin A into retinoic acid and saves the rest for storage
Retinoic Acid Reproduction
Nervous System
Epithelia (skin)
Immune Function
Recommended Dietary Allowance of Vitamin A 0.3 mg to 1.3 mg: age, sex, pregnancy, lactation
Toxic Intake 100 fold > RDA in adults
20 fold > in children
Vitamin K Koagulation
Mechanism of Vitamin K Action i) Targeted Protein (e.g. prothrombin)
ii) Vitamin K-dependent enzyme
iii) Modified Protein Binds Ca++(e.g. thrombin)
Vitamin K-Dependent Enzymes Activate specific target proteins by enabling them to bind to calcium.
Vitamin K Functions Essential for activating proteins required for:
Blood clotting
Blood vessel repair
Bone density
Preventing soft-tissue calcification
Warfarin A vitamin K antagonist that retards blood coagulation
