Nutrients Flashcards
Vitamin C function
- antioxidant
- protein/NT metabolism
- absorption of non-heme iron
Post-translational stages of collagen synthesis
Vitamin C deficiency
Scurvy -poor wound healing bleeding gums perifollicular hyperkeratosis petechial hemorrhage coiled hair
Tooth loss Impaired bone growth/bowing Impaired bone healing CNS Infection
Risk fx vitamin C deficiency
intestinal disease
malabsorption
EtOH
Vitamin C toxicities
bloating
diarrhea
Enhanced iron absorption
inc risk of oxalate kidney stones
Risk fx vitamin C toxicity
supplement use
fortified diets
Thiamine B1 function
Cofactor for many enzymes:
- transketolase (PPP)
- pyruvate DH (lactate)
- synthesis of Ach, GABA
Thiamine deficiency
Beriberi
- peripheral neuropathy
- HF/edema
Wernicke Korsakoff
- progressive CNS disorder
- ataxia
- confusion
- amnesia
- confabulation
Risk fx for thiamine deficiency
alcohol use,
persistent vomiting, GI disease, HIV/AIDS, refeeding syndrome, hyperemesis gravidarum
Niacin (B3) function
Synthesis of NAD and NADP
Niacin (B3) deficiency
Pellagra (4 D’s)
- dermatitis
- diarrhea
- dementia
- death
Risk fx for Niacin deficiency
lower SES, primarily corn diet
- malabsorption
- Hartnup’s (AR, tryptophan transport)
- carcinoid tumor
Niacin toxicity
flushing
high doses
- GI symptoms heartburn, nausea, vomiting.
- Hepatotoxicity.
- Hyperuricemia and gout (niacin competes with uric acid for excretion).
- Dec insulin sensitivity and glucose intolerance.
Folate function
- nucleotide synthesis
- methylation
Folate deficiency
pregnancy: neural tube defects
- megaloblastic anemia, dec regen of tissue
Risk fx of Folate deficiency
- generalized poor diet via illness/limited food ability
- EtOH use
- malabsorption disorders
- anticonvulsant drugs
Risk fx of Folate toxicity
upper limit is based on amount of folic acid likely to mask macrocytic anemia occurring due to vitamin B12 defciency
Vitamin B12 function
Cofactor of
- homocysteine –> methionine
- methylmalonyl CoA –> sucCoA
B12 deficiency
Megaloblastic anemia, neuropathies, changed mental status, glossitis, diarrhea and malabsorption
Risk fx of B12 deficiency
- vegans
- decreased IF
- bacterial overgrowth consuming B12
- impaired ileal absorption
- pernicious anemia
B12 toxicity
no upper limit/toxicity
B6 function
- enzyme cofactor (aa metabolism)
- porphobilinogen synthesis
- glycogenolysis
- gene expression
- supplemental tx for some sideroblastic anemias
B6 deficiency
- Seborrheic rash on face and extremities
- Weakness and fatigue
- Confusion
- Glossitis and cheilitis/angular stomatitis
- Peripheral neuropathy
- Seizures in infants
- Microcytic hypochromic anemia
Risk fx B6 deficiency
- poor intake
- EtOH (impairs conversion to PLP)
- malabsorption syndromes
- theophylline, cycloserine, penicillamine, valproic acid, carbamezpine, phenytoin, corticosteroids steroids
B6 toxicity
neurologic problems (peripheral nerves and dorsal columns (paresthesias and ataxia))
Risk fx B6 toxicity
via diet supplements, not food
supplements for
- hyperemesis gracidarum
- carpal tunnel
- premenstrual syndrome
*interactions w/ levodopa/phenytoin/phenobarbital/amiodarone/tetracyclines
Risk fx Vitamin A deficiency
- poor diet
- malabsorption
- liver disease
Vitamin A deficiency
Night blindness Abnormal epithelialization E.g. Xeropthalmia Impaired reproduction Infection E.g. respiratory, viral, diarrhea Stunting
Risk fx Vitamin A toxicity
- supplements
- renal disease
- not carotenoids
Vitamin A Toxicity
- anorexia
- HA
- abd pain
- liver disease
- teratogenicity
- osteoporosis
Risk fx Vitamin D Deficiency
Dietary -Exclusively breastfed infants -Fat malabsorption -Poor intake Limited sun Renal and liver disease Obesity
Vitamin D Deficiency
Children: Rickets
Adults: Osteomalacia
Myopathy and weakness
Long-term is contributor to osteoporosis risk
Risk fx Vitamin D toxicity
Supplements and Rx
Not sun
Rarely food
Vitamin D toxicity
Manifestations
- Hypercalcemia
- Nephrolithiasis
Risk fx Vitamin E deficiency
Very low birth weight/preterm infants
Fat malabsorption
α-tocopherol transfer protein defects (rare)
Vitamin E deficiency
Neuropathy
Myopathy
Retinopathy
RBC hemolysis
Risk fx Vitamin E toxicity
supplement use
Vitamin E toxicity
bleeding
mortality risk >400 IU/day
inhibitors of gastric acid
impaired digestion of food-bound vitamin B12
folic acid
masking of vitamin 12 deficiency
metformin
vitamin B12 deficiency
zinc supplements
copper deficiency
isoniazid
B6 deficiency with neuropathy
orlistat
fat soluble vitamin deficiency
high dose loop diuretics
thiamine deficiency
Risk fx Fe deficiency
Growth Menstruation Pregnancy Dietary inhibitors Malabsorption syndromes Intestinal parasites Vegetarians/vegans Athletes Blood loss
Fe deficiency
-anemia
-fatigue and lethargy
-cold intolerance
↓ psychomotor development
↓ intellectual performance
Impaired immunity
↑ risk of lead poisoning
Risk fx Zn deficiency
Acrodermatitis enteropathica
Malabsorption
Chronic diarrhea
Vegetarian diet
Zn deficiency
Rash Alopecia Diarrhea Infection Hypogeusia Hypogonadism Mental slowing Growth retardation
