Water Soluble Vitamins Flashcards
1
Q
Beriberi
A
- Thiamin B1 Deficiency
- “Dry” = peripheral neuropathy; muscle tenderness, weakness & atrophy; foot drop
- “Wet” = edema, circulatory collapse, CHF
- Wernicke-Korsakoff (cerebral beriberi): confusion, opthalmoplegia, ataxia, memory loss
2
Q
Food sources for thiamin riboflavin, and niacin
A
Thiamin: pork, legumes
Riboflavin: dairy, eggs, meats
Niacin: meat/poultry; tryptophan = precursor
- All involved in glycolysis/Krebs cycle
- TPP, FAD, NAD; decarboxylation, oxidation-reduction
3
Q
Risk for thiamin deficiency
A
- Alcoholics
- s/p bariatric surgery
- TPN
- Anorexia nervosa
- re-feeding
- endemic in So Asia
4
Q
What physical symptoms do you get from B2 deficiency?
A
Riboflavin deficiency
- Cheilosis
- Angular stomatitis
5
Q
What does B3 deficiency lead to?
A
Pellagra
- Malabsorption syndromes
- nutritional/dietary restriction
- Alcoholism
- Metabolic shunting (carcinoid tumor)
6
Q
4 D’s of Pellagra
A
- Diarrhea
- Dermatitis (scaling w/ areas of depigmentation and hyperpigmentation; aggravated by sun exposure - Casal’s necklace)
- Dementia
- Death
7
Q
Folic Acid
A
Function: Single C transfers for DNA methylation
Food sources:
- foliage, deep green veg
- orange juice
- whole grains
8
Q
Situations with risk of folate deficiency
A
- inadequate intake or increased destruction in food
- alcoholics
- pregnancy
- hematopoietic conditions
- drug/nutrient interactions
9
Q
Signs of folate deficiency
A
- macrocytic anemia (inc. MCV)
- hypersegmented neutrophils
- glossitis, irritability
- homocysteinemia
- NTD
10
Q
How much folate should be taken to prevent NTD
A
400-800 micrograms/day
11
Q
Vitamin B-12
A
- Forms tetrahydrafolate from methylfolat (synthesis of methionine)
- catabolism of odd chain length fatty acids
- catalyze isomerization of methylmalonyl Co-A to succinyl Co-A (lipid and CHO metabolism)
- methylation
- interactions essential for homocysteine –> methionine, protein synthesis, nucleic acid synthesis
12
Q
Absorption of B12
A
- Cleave vitamin from dietary protein in stomach
- Requires IF from stomach
- Cobalamin-IF complex absorbed in distal ileum
- Transport into circulation with transport protein transcobalamin II
13
Q
Food sources for B12
A
- soil bacteria
- animal products
vegans should take a supplement
14
Q
Risk factors for B12 deficiency
A
- Inadequate IF secretion or antibodies to IF
- gastric atrophy/gastrectomy
- ileal resection
- breastfed infant of B12 deficient vegan mother
15
Q
Effects of B12 deficiency
A
- macrocytic anemia & hypersegmented neutrophils
- neurologic disturbances (depression, paresthesias, gait disturbances, burning tongue, dizziness)
