Water soluble vitamins

Question 1

Biochemical function of Thiamin

Answer 1

PDH cofactor

Question 2

Sources of Thiamin

Answer 2

legumes, rice bran, grains

Question 3

Biochemical function of Riboflavin

Answer 3

Involved in Glycolysis/TCA cycle

Question 4

Sources of Riboflavin

Answer 4

dairy, eggs, meat

Question 5

Biochemical function of Niacin

Answer 5

Involved in Glycolysis/TCA cycle

Question 6

Sources of Niacin

Answer 6

meat/poultry. Tryptophan is a precursor. Corn with alkaline treatment

Question 7

What is dry Beri-Beri

Answer 7

Thiamin Deficiency- neuropathy, muscle tenderness weakness and atrophy

Question 8

What is wet Beri-Beri

Answer 8

Thiamin Deficiency- edema, circulatory collapse, congestive heart failure

Question 9

What is Wernicke-Korsakoff

Answer 9

Thiamin deficiency- confusion, ophthalmoplegia, ataxia, memory loss (complete correction 25%; partial 50%); peripheral neuropathy

Question 10

Risk for deficiency

Answer 10

Alcoholics
Vomiting (e.g. s/p bariatric surgery (esp 1st 6 mo post-op)
TPN (total parenteral nutrition), w/o thiamin(deficiency occurs w/in 2-3 wk)
Anorexia nervosa
Re-feeding
Endemic in So Asia (maternal & BF infant) – polished rice diet;

Question 11

What happens with riboflavin deficiency

Answer 11

cheilosis and angular stomatitis

Question 12

What happens with Niacin deficiency

Answer 12

Pellagra:
Diarrhea
Dermatitis
Dementia
Death

Question 13

Risk for niacin deficiency

Answer 13

Nutritional/dietary restriction
Cornmeal (w/o germ) based diet (esp w/o alkaline/lime treatment)
Food faddism / restriction
Malabsorption syndromes
Alcoholism
Metabolic “shunting” (carcinoid tumor  ↑ serotonin   tryptophan)

Question 14

Biochemical function of folic acid

Answer 14

single C transfers-
nucleic acid synthesis
amino acid metabolism
DNA Methylation

Question 15

Dietary sources of folic acid

Answer 15

“foliage,” deep green veg, orange juice, whole grains

Question 16

Risk for deficiency of folic acid

Answer 16

Inadequate intake or increased destruction in food
Alcoholics
Pregnancy – globally, high rates deficiency; WHO: routine supplementation, women of reproductive age

Hematopoietic conditions
Drug/nutrient interactions

Question 17

Symptoms of folic acid deficiency

Answer 17

*Macrocytic anemia
*Hypersegmented neutrophils
*Glossitis, irritability
*Homocysteinemia
Neural tube defects (occurrence/recurrence)

Question 18

Biochemical function of B12

Answer 18

Reform tetrahydrafolate from methylfolate (synthesis of methionine)
Catabolism of odd chain length fatty acids
Catalyze isomerization of methylmalonyl Co-A  succinyl Co-A (lipid & CHO metabolism)

Question 19

Dietary sources of B12

Answer 19

Animal products

Question 20

B12 absorption

Answer 20

Cleave vitamin from dietary protein in stomach
Requires Intrinsic Factor from stomach
Cobalamin-IF absorbed in distal ileum
Transport in circulation: Transcobalamin II
Large liver stores

Question 21

Risk factors for B12 deficiency

Answer 21

Inadequate IF secretion or antibodies to IF
Gastric atrophy/gastrectomy
Ileal resection
Breastfed infant of B12 deficient vegan mother

Question 22

B12 deficiency symptoms

Answer 22

Macrocytic anemia & hypersegmented neutrophils

Neurologic disturbances: depression, paresthesias, gait disturbances, burning tongue, dizziness

Question 23

What is the water soluble vitamin you can overdose on?

Answer 23

B6

Question 24

What is the biochemical function of Vit C

Answer 24

Reversible Antioxidant- Vit E sparing
Provides reducing equivalents to enzymes:
Reduction of iron    absorption
Leukocyte function ( [AA] wbc)
Co-substrate in hydroxylation: 
Collagen synthesis: hydroxylation of proline & lysine; cross-links for tropocollagen
Hydroxylation of tryptophan  serotonin
 Conversion dopamine  norepinephrine

Question 25

Dietary Sources of Vitamin C

Answer 25

Fruits and vegetables

Question 26

What happens with vit C deficiency?

Answer 26

Scurvy-
Hemorrhagic gums
Hyperkeratosis of hair follicles + perifollicular hemorrhages
Hypochondriasis: depression, weakness
Hematologic abnormalities
Anemia: iron &/or folate deficiencies, bleeding
Progression: weakness, aching joints/bones/muscles, hemorrhagic signs