Water Soluble Vitamins Flashcards
Generally not “stored” in body
(_____ = exception)
Chronic intakes do alter tissues levels
Toxicity usually low (B6 = exception)
B12
Generally not “stored” in body (B12 = exception) Chronic intakes do alter tissues levels Toxicity usually low (\_\_\_\_ = exception)
B6
Energy Releasing
B Complex Vitamins are
Energy Releasing
Thiamin (B1) /Riboflavin (B2) /Niacin (B3)
Beriberi
- nervous & cardiovascular systems
“Dry:” peripheral neuropathy; muscle tenderness (esp legs), weakness & atrophy; foot drop- more common
“Wet:” edema, circulatory collapse, congestive heart failure
Thiamin (B1) Deficiency
All involved in glycolysis/Krebs cycle
TPP, FAD, NAD; decarboxylation, oxidation-reduction
Thiamin (B1) /Riboflavin (B2) /Niacin (B3)
Wernicke-Korsakoff
confusion, ophthalmoplegia, ataxia, memory loss (complete correction 25%; partial 50%)
thiamine def
Thiamin Deficiency – Who’s at Risk
Alcoholics bariatric surgery TPN w/o thiamin-- deficiency occurs w/in 2-3 wk Anorexia nervosa Endemic in Asia- from rice
Peripheral neuropathy
Muscle weakness/atrophy
Foot drop
Eventual inability to walk w/o falling
Thiamin Deficiency:
Dry beri-beri
Ophthalmoplegia
Memory loss
Confusion
Ataxia
Thiamin Deficiency:
Cerebral beri-beri
Pellagra
Niacin (B3) Deficiency
4 Ds Diarrhea Dermatitis Dementia Death
Riboflavin (B2) Deficiency
Mouth findings:
cracked lips= Cheilosis
Angular stomatitis
B2 In dairy
Niacin (B3) Deficiency risks
Malabsorption syndromes
Alcoholism
Metabolic “shunting” (carcinoid tumor depletes tryptophan)
refined cornmeal or rice diet
Dermatitis w/ pellagra
symmetric, scaling w/ areas depigmentation & hyperpigmentation
aggravated by sun exposure (“Casal’s necklace”)
B Complex Vitamins: Hematopoietic
Folate
Vitamin B-12
single C transfers
nucleic acid synthesis
amino acid metabolism
DNA Methylation - epigenetics
Folic Acid
folate= foliage= comes from green leaf veggies
*Macrocytic anemia
*Hypersegmented neutrophils
*Glossitis, irritability
*Homocysteinemia
Neural tube defects
Signs/symptoms ofFolate Deficiency
Folate (& Vit B-12) Deficiencies in blood
Macrocytic Anemia (↑ MCV) + Hypersegmented Neutrophils
Women of child bearing age advised to have intake of 400-800 ug/day* to prevent _______
neural tube defects (spina bifida, anencephaly)
Neural tube closes by _____ gestation - before most women realize they are pregnant
4-6 wk
Methylation
Catabolism of odd chain length fatty acids
lipid & CHO metabolism
Vitamin B-12 (cobalamin) fx
Vit B12 Absorption
not easy like other water vits
Cleave vitamin from dietary protein in stomach
Requires Intrinsic Factor from stomach
Cobalamin-IF absorbed in distal ileum
Transport in circulation: Transcobalamin II
Vitamin B-12:Dietary Sources & Requirements
only in animal products- Synthesized by soil bacteria
Vegans should take a supplement
Vitamin B-12: Deficiency risk factors
Inadequate IF secretion or antibodies to IF
Gastric atrophy/gastrectomy
Ileal resection
Breastfed infant of B12 deficient vegan mother
Vitamin B-12: Deficiency
Same as folate:
Macrocytic anemia & hypersegmented neutrophils
These are unique:
Neurologic disturbances: depression, paresthesias, gait disturbances, burning tongue, dizziness
Vitamin B-12 seriousness
Hematological effects are reversible w/ B12 or folate Rx
Neurological effects eventually irreversible
_______________ should not be treated w/ folate unless have ruled out Vitamin B-12 deficiency
Megaloblastic anemia
Reversible antioxidant, Vitamin E sparing
Provides reducing equivalents to enzymes: Reduction of iron absorption
Leukocyte function (↑ [AA] wbc)
Ascorbic Acid (Vitamin C)
Functions & Physiologic Roles
Vit C
Co-substrate in hydroxylation:
Collagen synthesis: hydroxylation of proline & lysine; cross-links for tropocollagen
Hydroxylation of tryptophan serotonin
Vitamin C – Food Sources
f/v
potato
Vitamin C Deficiency s/s
Classic: Bleeding gums
Hemorrhagic signs
Hyperkeratosis of hair follicles + perifollicular hemorrhages
Hypochondriasis: depression, weakness
Hematologic abnormalities
Progression: weakness, aching joints/bones/muscles, hemorrhagic signs
Ecchymoses, petechiae Hyperkeratosis of hair follicles,
Scurvy
6 mo old breastfed infant, vomiting, ophthalmoplegia, congestive heart failure
beri beri
5 yr old child only eats burgers (w/ bun) & milk, now limping & refusing to walk, ~ rash
needs vit c
Alcoholic, “found down”, altered mental status, anemic
needs b12, thiamine, folate
15 mo old breastfed infant, growth faltering, no longer walking
needs b12
Adult, low SES, chronic diarrhea/malabsorption, rash on arms, hands, neck
pellagra
