Vitamins and Nutrition

Question 1

Vitamins

Answer 1

Small molecules important as cofactors in many biological/enzymatic reactions

Question 2

Deficiency

Answer 2

Due to either inadequate diet, inadequate GI absorption, competing organisms (e.g., parasites)

Question 3

Insufficiency

Answer 3

Due to increased metabolism that mandates intake and absorption of greater than normal levels

Question 4

Toxicity

Answer 4

Abnormally high intake that can lead to pathology (mostly leading to either hepatic or kidney damage)

Question 5

Vitamin B1 other name and function

Answer 5

• Thiamine
• Coenzyme for energy metabolism

Question 6

Vitamin B2 other name and function

Answer 6

• Riboflavin
• Precursor for coenzymes FMN or FAD, redox reactions

Question 7

Vitamin B3 other name and function

Answer 7

• Niacin
• Precursor to coenzyme NAD, dehydrogenase reactions

Question 8

Vitamin B5 other name and function

Answer 8

• Pantothenic acid
• Component of Coenzyme A

Question 9

Vitamin B6 other name and function

Answer 9

• Pyridoxine
• Aa metabolism and transport, heme synthesis

Question 10

Vitamin B7 other name and function

Answer 10

• Biotin
• Coenzyme for carboxyl unit transfer

Question 11

Vitamin B12 other name and function

Answer 11

• Cyanocobalamin
• Hematopoiesis, fatty acid metabolism

Question 12

Folate/folic acid (vit B9) function

Answer 12

Coenzyme for one-carbon transfer reactions and aa metabolism

Question 13

Vitamin C (ascorbic acid) function

Answer 13

• hydrogen ion transfer
• redox reactions
• aa metabolism
• collagen synthesis

Question 14

Vit A (retinol) function

Answer 14

• Vision
• Cell differentiation
• Growth
• Reproduction
• Immune system function

Question 15

Vitamin D function

Answer 15

controls calcium and phosphate metabolism

Question 16

Vitamin E function

Answer 16

• Antioxidant
• Peroxide breakdown
• Cellular integrity

Question 17

Vitamin K function

Answer 17

Cofactor for post-translational carboxylation of many proteins and clotting factors. Give Vit K shots to newborns to aid clotting

Question 18

Biochemically, vitamins are most easily studied within groups defined by ___

Answer 18

hydrophobicity

Question 19

List fat-soluble vitamins

Answer 19

A, D, E, K

Question 20

Water soluble-vitamins

Answer 20

Vit C
B1, B3, riboflavin, B5, B6, B7, B12

Question 21

Fat soluble vitamin solubility properties

Answer 21

• Dissolve in fat before bloodstream absorption
• Process requires bile acids from the liver
• Carried by lipoproteins

Question 22

Vit E carried by which lipoprotein?

Answer 22

LDL

Question 23

Fat soluble vitamins mainly stored where? Where do they go if not stored?

Answer 23

• Intestines, liver, and fatty tissues
• Greater risk of toxicity due to storage
• Excreted in feces if not stored

Question 24

Water soluble vitamin storage and elimination

Answer 24

• Not stored in body, so less chance of toxicity
• Regularly eliminated in urine and feces
• Constant re-supply needed

Question 25

Water soluble vitamin toxicity

Answer 25

Less chance of toxicity BUT impaired secretion in renal damage

Question 26

Major site of vitamin absorption

Answer 26

Small intestine

Question 27

Vitamin metabolism pathway

Answer 27

1. Nutrients enter at cellular level 2. Picked up and absorbed by blood capillaries and lymph fluids thru active transport/diffusion/osmosis

Question 28

Where are Vitamin B12 and Vitamin K metabolized?

Answer 28

Large intestine

Question 29

List most commonly assayed vitamines

Answer 29

- Folate (Vit B9) - Vit B12 - Vit D

Question 30

**ID the vitamin** Most common vitamin deficiency Can lead to megaloblastic anemia

Answer 30

Folate (Vit B9)

Question 31

Which pathologies depend on normal folate levels (feature folate deficiency)?

Answer 31

- Megaloblastic anemia - Neural tube defects - Increased levels of atherosclerosis related to homocysteine turnover on appropos vitamin levels

Question 32

Folate tested on which sample types?

Answer 32

Serum and RBC hemolysate

Question 33

**ID the vitamin** Absorption dependent on Intrinsic Factor Associated with megaloblastic anemia/pernicious anemia Transcobalamins transport this vitamin

Answer 33

Vit B12 (cyanocobalamin)

Question 34

Vit B12 testing

Answer 34

Serum or plasma Similar to folate assays

Question 35

**T/F** Lots of foods contain Vit D

Answer 35

False

Question 36

Vit D important for assessing what?

Answer 36

- parathyroid function - bone development - chronic renal failure - monitoring vit D therapy - vit D toxicity - small bowel disease - pancreatic insufficiency - drug-related hypovitaminosis

Question 37

Vit D from the diet or skin synthesis is biologically ___

Answer 37

inactive

Question 38

What is required for Vit D activation?

Answer 38

Enzymatic conversion in liver and kidney

Question 39

Marasmus

Answer 39

- Diet deficient in both **protein and calories** - Most severe -> general wasting

Question 40

Kwashiorkor

Answer 40

- Diet adequate in calories but **deficient in protein** - Less severe than marasmus - Visceral muscle protein loss but no skeletal muscle loss

Question 41

Negative outcomes of malnutrition

Answer 41

- Increased mortality/morbidity - Impaired wound healing - Increased rate of infection - Increased length of hospital stay

Question 42

Lab methods to assess nutritional status

Answer 42

- selected protein markers most useful - hematology assays (Hgb, Hct, WBC, lymphs) - immunology assays (increased TDT, cytokine levels) - non-protein chemistry (vitamin analysis, BUN/creatinine, cholesterol/triglyceride, mineral levels)

Question 43

List protein markers used to assess nutritional status

Answer 43

- transferrin - pre-albumin (transports T4 and retinol) - retinol-binding protein (RBP) (vit A transport) - albumin/aa/IGF-1/leptin

Question 44

**T/F** One single protein marker can assess overall nutritional status

Answer 44

False, need more

Question 45

Protein markers may provide info on:

Answer 45

- metabolic status - determining prognosis - monitoring of nutrition support

Question 46

Useful protein combo to assess nutritional status

Answer 46

Plasma markers (usually pre-albumin/transthyretin) + acute phase reactant like CRP

Question 47

What does the following indicate: Normal CRP Low pre-albumin

Answer 47

Protein malnutrition

Question 48

What does the following indicate: Significantly increased CRP Low pre--albumin

Answer 48

There may be false decrease in pre-albumin

Question 49

What CRP and pre-albumin lab results indicate improving protein nutrition status?

Answer 49

Decreasing CRP and increasing pre-albumin

Question 50

Total parenteral nutrition (TPN)

Answer 50

Necessary if GIT not properly functioning or when patient cannot take anything by mouth

Question 51

TPN complications

Answer 51

- fluid/electrolyte imbalance - acid-base imbalance - glycosuria - hyperglycemia - liver/hematologic abnormalities - vitamin/mineral deficiencies