Nutrition Flashcards
Fat soluble vitamins
A, D, E, K
What type of vitamins are more commonly accumulate to toxic levels
Fat soluble vitamins since accumulate in fat
Common causes of malabsorption syndromes with steatorrhea that lead to fat-soluble vitamin deficiencies
Cystic fibrosis, celiac disease, or mineral oil intake
Site of B12 storage
Liver
Duration of B12 storage before symptoms develop
3-4 years
Symptoms of B-complex deficiencies
Dermatitis, glossitis, and diarrhea
Thiamine
Vitamin B1
Function of vitamin B1
In thymine pyrophosphate (TPP), a cofactor for several dehydrogenase reactions
Enzymes that require vitamin B1
Alpha-ketoglutarate dehydrogenase, Transketolase, Pyruvate dehydrogenase (think ATP)
Consequence of vitamin B1 deficiency in alcoholics or malnourished patients
Wernicke-Korsakoff syndrome and Beriberi
Classic triad of Wernicke-Korsakoff syndrome
Confusion, ataxia, and ophthalmoplegia
Damage caused by Wernicke-Korsakoff syndrome
Damage to medial dorsal nucleus of thalamus and mammillary bodies
How is diagnosis of vitamin B1 deficiency made?
Increased RBC transketolase after giving vitamin B1
Tissues more affected first by vitamin B1 deficiency
Highly aerobic tissues like brain and heart
Disease in vitamin B1 deficiency that presents with polyneuritis and symmetrical muscle wasting
Dry beriberi
Treatment for alcoholics or malnourished patients
Give thiamine before glucose to prevent Wernicke encephalopathy
Disease in vitamin B1 deficiency that presents with dilated cardiomyopathy and edema
Wet beriberi
Inflammation of lips, scaling, and fissures at the corners of the mouth
cheilosis
FAD and FMN are derived from what vitamin
Vitamin B2
Two cofactors derived from vitamin B2 used in redox reactions
FAD and FMN
Consequence of vitamin B2 deficiency
Cheilosis and corneal vascularization
Cofactors derived from vitamin B2
FAD and FMN
Which B vitamin is niacin
Vitamin B3
Which B vitamin is riboflavin
Vitamin B2
Vitamin that is an essential component of coenzyme A
Vitamin B5
Consequence of vitamin B3 deficiency
Glossitis and pellagra
What amino acid is niacin derived from?
Tryptophan
Synthesis of niacin requires what two vitamins
Vitamin B3 and B6
Autosomal recessive disorder that can cause niacin deficiency
Hartnup disease
Causes of niacin deficiency
Hartnup disease, isoniazid, malignant carcinoid syndrome
Symptoms of Pellagra
Diarrhea, Dementia, Dermatitis
Patient who presents with dermatitis, enteritis, alopecia, and adrenal insufficiency is deficient in what vitamin
Vitamin B5
Other name for vitamin B5
Pantothenic acid
Presentation of excess nitrogen
Facial flushing, hyperglycemia and hyperuricemia
Facial flushing in niacin excess can be avoided how?
Taking aspirin with niacin
Mechanism of Hartnup disease
Not enough niacin made since not enough tryptophan is reabsorbed due to insufficient neutral amino acid transporters in proximal renal tubular cells and enterocytes
Treatment for Hartnup disease
High protein diet and nicotinic acid
What vitamin is found in NAD and NAD+
Niacin (B3)
Patient who presents with broad collar rash, hyperpigmentation of sun-exposed skin with diarrhea and dementia is deficient in what vitamin
Vitamin B3 (niacin)
What vitamin is an essential component of CoA and fatty acid synthase
Vitamin B5 (pantothenic acid)
Vitamin converted to pyridoxal phosphate, a cofactor in transamination, decarboxylation rxns, and glycogen phosphorylase
Vitamin B6
Other name for vitamin B6
Pyridoxine
Drugs that cause vitamin B6 deficiency
Isoniazid and OCPs
Symptoms of vitamin B6 deficiency
Convulsions, hyperirritability, peripheral neuropathy
Type of anemia caused by vitamin B6 deficiency
Sideroblastic anemia
Neurotransmitters that require vitamin B6
Serotonin, epinephrine, NE, dopamine, GABA
Cofactor for carboxylation enzymes
Vitamin B7 (biotin)
What can cause biotin deficiency?
Antibiotic use or eating too many egg whites
What component in egg whites causes biotin deficiency?
Avidin
Vitamin important in synthesis of nitrogenous bases in DNA and RNA
Folate (Vitamin B9)
Other name for vitamin B7
Biotin
What is folate converted to?
THF, a coenzyme for 1-carbon transfer/methylation reactions
Source of folate
Leafy green vegetables
Part of GI tract that absorbs folate
Jejunum
Type of anemia caused by folate deficiency
Macrocytic, megaloblastic anemia
Labs indicating folate deficiency
Increased homocysteine and normal methylmalonic acid
Other name for vitamin B12
Cobalamin
Most common vitamin deficiency in the U.S. and seen in alcoholism and pregnancy
Folate deficiency (B9)
Source of B12
Animal products
Neurological deficit caused by B12 deficiency
Paresthesias from degeneration of dorsal columns, lateral corticospinal tracts, and spinocerebellar tracts
Lab values seen in B12 deficiency
Increased homocysteine and methylmalonic acid and folate deficiency
Consequence of prolonged B12 deficiency
Irreversible nerve damage
Part of GI tract that absorbs vitamin B12
Terminal ileum
Vitamin B12 binding protein required for proper absorption
Intrinsic factor
Type of diet that causes B12 deficiency
Veganism
Storage site for B12 in body
Liver
Function of ascorbic acid
Antioxidant and reduces iron
Source of vitamin C
Fruits and vegetables
Consequence of Vitamin C deficiency
Scurvy
Vitamin C is required for hydroxylation of what two amino acids
Proline and lysine in collagen synthesis
Collagen synthesis defect that presents with corkscrew hair and poor wound healing
Scurvy
Symptoms of excess vitamin C
Nausea, vomiting, diarrhea, fatigue, calcium oxalate nephrolithiasis
Vitamin C excess increases the risk of what in those with transfusion or hereditary hemochromatosis
Iron toxicity
Other name for vitamin D2
Ergocalciferol
Source of ergocalciferol
Plants
Other name for vitamin D3
Cholecalciferol
Source of cholecalciferol
Sun-exposed skin and milk
Storage form of vitamin D
25-OH D3
Active form of vitamin D
1,25-(OH)2 D3
Function of vitamin D
Increased intestinal absorption of calcium and phosphate
Low levels of vitamin D increase what bone process
Increased bone mineralization
Vitamin D deficiency in children
Rickets
Vitamin D deficiency in adults
Osteomalacia
High levels of vitamin D increases what bone process
Increased bone resorption
Malnutrition not causing edema resulting in muscle wasting
Marasmus
Kwashiorkor results from deficiency of which macromolecule
Protein
Presentation of Kwashiorkor
Edema, anemia, fatty liver, and skin lesions
Cause of fatty liver in Kwashiorkor
Decreased apolipoprotein synthesis
Cause of edema in Kwashiorkor
Decreased plasma oncotic pressure
Vitamin important in transcription factor motif
Zinc
Presentation of Zinc deficiency
Delayed wound healing, hypogonadism, decreased adult hair
Vitamin K dependent clotting factors
Factors II, VII, IX, X, protein C and S
What anticoagulant inhibits vitamin K
Warfarin
Acrodermatitis enteropathica is seen in what vitamin deficiency
Zinc
Vitamin that protects RBCs and membranes from free radical damage
Vitamin E
What does vitamin D do to warfarin
Enhances its anticoagulation effects
Presentation of vitamin E deficiency
Hemolytic anemia, acanthocytosis, muscle weakness, posterior column and spinocerebellar tract degeneration
Other name for vitamin E
Tocopherol or tocotrienol
Enzyme that activates vitamin K
Epoxide reductase
Why are neonates given vitamin K injection at birth
Prevents hemorrhagic disease since cannot make vitamin K (sterile intestines)