Water soluble Vitamins

Question 1

Does chronic intake alter tissue levels?

Answer 1

yes

Question 2

Toxicity?

Answer 2

usually low

B6 = exception

Question 3

Absorption

Answer 3

usually high

Question 4

Breast milk reflective of maternal status?

Answer 4

yes, except folate?

Question 5

Excretion

Answer 5

via urine

Question 6

Energy releasing

Answer 6

Thiamine
Riboflavin
Niacin

Question 7

Hematopoietic

Answer 7

folic acid

B12

Question 8

Non B complex

Answer 8

ascorbic acid vitC

Question 9

Thiamine
Riboflavin
Niacin

function

Answer 9

all involved in glycolysis / TCA

Question 10

Thiamine
Riboflavin
Niacin

sources

Answer 10

whole and enriched grains

Thiamin - legumes (decreased in polished rice)

Riboflavin - dairy, eggs, meat

Niacin: meat/poultry (tryptophan = precursor)

*corn is a poor source unless alkaline-treated

Question 11

Thiamin deficiency

Answer 11

BeriBeri - Nervous and cardiovascular systems

Dry - peipheral neuropathy - weakness and atrophy

Wet - edema, CHF

Wernicke-Korsakoff (Cerebral) - confusion, ophthalmoplegia, ataxia, memory loss

Question 12

Thiamin deficiency

who is at risk?

Answer 12

alcoholic 
voming 
s/p bariatric surgery 
TPN
AN
Re-feeding 
Endemic in So Asia - polished rice

Question 13

Infantile beriberi

Answer 13

infant formula w/o thiamin
- vomiting / infection / lethargy / ophthalmoplegia / low thiamine PPi

Prompt response to high dose (50mg/d x 2wk)

Question 14

Riboflavin deficiency

Answer 14

Cheilosis
Angular stomatitis

Low dairy, animal products, common in low resource setting

Question 15

Niacin deficiency

Answer 15

Pellagra (D4)
Dermatitis
Dementia 
Diarrhea
Death

Question 16

Dermatitis in Niacin deficiency

Answer 16

scaling with areas of depigmentation and hyperpigmentation - aggrevated by sun

Question 17

Niacin deficiency predisposing factors

Answer 17

Nutritional/dietary restriction
cornmeal based diet

Malabsorption

Alcoholism

Metabolic shuting (carcinoid tumor)

Question 18

Folic acid (Folate)
Functions

Answer 18

single carbon transfers

• nucleic acid synthesis
• amino acid metabolism
• epigenetics (methylation)

Question 19

Folic acid (folate)
sources

Answer 19

foliage -
orange juice
whole grains - enriched
easily destroyed in prolonged cooking

Question 20

risk of folate deficiency

Answer 20

inadequate intake or increased destruction of food

alcoholics

pregnancy - globally higher rates

hematopoietic conditions
drug/nutrient interactions

Question 21

folate deficiency

signs and symptoms

Answer 21

macrocytic anemia 
hypersegmented nuets
glossitis
irritability 
homocysteinemia 
(above are reversible)
neural tube defects

Question 22

folate supplementation

Answer 22

400-800microgram/day for women of child bearing age - to prevent neural tube defects
important pre-conceptus as neural tube closes 4-6wk gestation

Question 23

VitB12 cobalamin

functions

Answer 23

reforms THF from methylfolate (necessary for synthesis of methionine)

catabolism of odd chain FA

isomerization of methylmolonyl CoA to succinyl CoA (lipid and CHO metabolism)

One carbon transfers (methylation)

METABOLISM INTIMATELY RELATED TO FOLATE

Interactions essential for homocysteine –> methionine, protein synthesis, nucleic acid synthesis

Question 24

VitB12 absorption
stomach?
ilieum?

Answer 24

requires IF from stomach

Cobalamin-IF absorbed in distal ileum

Transport in circulation as transcobalaminII

Question 25

VitB12
absorption
storage
excretion

Answer 25

enterohepatic circulation

large liver stores

excretion: primarily via bile

Question 26

Vit B12 sources

Answer 26

only in animals
synthesized in soil bacteria
vegans should take supplement

Question 27

B12 deficiency at risk?

Answer 27

inadequate IF or antibodies to IF

Gatric atrophy

Ileal resection

Breasfed infant of B12 deficienct mom

Question 28

B12 deficiency effects?

Answer 28

Macrocytic anemia
Hyperseg nuets

nuerologic disturbance - depression / parasthesias / dizzy / gait

Question 29

B12 deficiency

reversible effects?

Answer 29

Hematologic effects are reversible with B12 or folate

neurological effects eventually irreversible

MEGALOBLASTIC ANEMIA SHOULD NOT BE TREATED WITH FOLATE UNLESS B12 RULED OUT!!

Question 30

Vitamin C

Functions

Answer 30

Cosubstrate in hydoxylation: collagen synthesis ; seratonin synthesis from typtophan

Converstion of Dopamine to norepinephrine

Reversible antioxidant
Reduction of iron –> increased absorption

Leukocyte function

Question 31

VitC food sources

Answer 31

Fruits and Veggies 
US
39% F
15% Potatoes 
38% other vegetables

Question 32

VitC intake/absorption

Answer 32

Saturable

If taking large doses divid into <1g/dose

Question 33

VitC absorption homeostasis

Answer 33

if you increase intake the GI will decrease absorption

Renal excretion limits plasma levels

Intakes of 400-500mg –> no increase in plasma concentration

Question 34

VitC deficiency

Answer 34

Scurvy
Hemmorhagic signs 
Hyperkeratosis of hair follicles
Hypochondriasis 
Hematologic anomalies - anemia - iron or folate deficiencies

Question 35

VitC deficiency progression

Answer 35

weakness - aching - joints - bones - muscles - hemorrhagic

Question 36

Scurvy in children

Answer 36

Autism link

Question 37

Benefits of megadoses of VitC?

Answer 37

Common cold - decrease duration of symptoms?

Wound healing -

Question 38

6 mo old breastfed infant, vomiting, ophthalmoplegia, CHF

Answer 38

Beriberi - wet - Thiamin

Question 39

5 year old eats only burgers with bun and milk, now limping and refusing to walk, with “rash”

Answer 39

Scurvy - vitamin C

Question 40

Alcoholic “found down” altered mental and anemic

Answer 40

Could be thiamin or folate

Question 41

Obese adolescent s/p bariatric surgery, can’t walk, falls down

Answer 41

Thiamin (BeriBeri)

Question 42

Adult, low SES, chronic diarrhea, malabsorption, rash on arms, hands, neck

Answer 42

Niacin