Nutritional Deficiencies Flashcards
How does acute and chronic alcohol intake cause malnutrition?
- Decrease calorie intake
- Interfere with nutrient digestion and absorption
- Reduce protein synthesis and secretion
- Breakdown of gut proteins
- Increasing excretion of nutrients
Causes of malnutrition
Nausea, vomiting Diarrhea Poor food availability/quality Dietary restriction (anorexia, etc.) Metabolic disturbances (hypermetabolism/catabolism) Alcoholism Cytokine effects Complications of liver disease
Vitamin A (retinol)
Dietary Source: liver,fish,eggs,milk
Carotenoids (yellow and leafy green veggies)
Functions:
Visual pigment
Specialized epithelia
Resistance to infection
Vitamin A toxicity
Too much vitamin A
Acute: headache, vomiting, stupor, death
Chronic: weight loss, vomiting, dry lips, bone and joint pain
Congenital malformations: why accutane (synthetic retinoids) are contraindicated during pregnancy
Carotenemia
Excessive vitamin A precursors Eating too many carrots or leafy veggies Orange skin (palms and soles) Sclera remain white Not associated with toxicity
Vitamin D (sources, causes of deficiency, function, signs of deficiency)
Sources:
Endogenous: We make from sunlight
Diet: Most dairy products are fortified
Causes of deficiency:
No calcium or vitamin D
No sunlight (veiled women, northern latitudes)
In children with mothers who have frequent pregnancies (lactation)
Functions: intestinal absorption of calcium and phosphorus and mineralization of bone
Signs/symptoms of deficiency:
Rickets in children (bone has not closed)
Osteomalacia
Weakness of proximal muscles (closest to midline)
Bone pain and tenderness
Hypocalcemia
Osteomalacia vs. Rickets
Osteomalacia: epiphyses have closed in adults
Rickets: epiphyses have not closed (bowing)
Epiphyses: end part of the long bone, initially growing separately from the shaft
Vitamin C (functions and sources)
Water soluble vitamin
Functions: antioxidant and formation of collagen (important for hydroxylation of procollagen)
Sources: fruits and veggies
Scurvy
Disease of vitamin C deficiency
Bone disease in growing children and by hemorrhage and healing defects in children and adults
People at risk: elderly who live alone, alcoholics, infants fed only processed milk
Ex. thin, elderly woman, bad diet; boy who ate only cookies
Vitamin C (signs/symptoms)
Weakness, easy fatigue
Aching bones, joints, muscles, esp. at night
Acne
Defects of hairs on body (corkscrew hairs, swan neck deformities)
Easy bruising
Loss of teeth
Fat soluble vitamins
Vitamin A, D, E, K
Water soluble vitamins
Vitamin B1, B2, B6, B12 Niacin Vitamin C Folate Zinc Iron
Vitamin A (signs/symptoms of deficiency)
Night blindness
Xerosis (eye dryness)
Keratomalacia (loss of functional keratin)
Corneal ulceration and blindness
Perifollicular hyperkeratosis (accumulation at Hyperkeratonized skin around hair follicles, seen on upper arms and thighs)
Squamous metaplasia: benign change of epithelia
Vulnerability to infection
Vitamin E
Function:
Major antioxidant
Scavenges free radicals
Deficiency syndromes: spinocerebellar degeneration
Vitamin K
Function:
Cofactor in hepatic carboxylation of procoagulants: factors II (prothrombin), VII, IX, X, and protein C and S
Deficiency syndromes: Bleeding diathesis (too much bleeding)
Vitamin B1 (Thiamine)
Function:
Pyrophosphate, coenzyme in decarboxylation reactions
Deficiency:
Dry and wet beriberi
Wernicke syndrome (encephalopathy)
Korsakoff syndrome (psychosis)
Causes mito dysfunction and oxidative toxicity in brain
Brainstem, pons, midbrain occulomotor dysfunction
Cerebellum: ataxia (body movements)
Diancephalon, medial thalamus, amygdala- amnesia and confusion
Vitamin B2 (riboflavin)
Source: meat, dairy, veggies
Function:
Converted to coenzymes flavin mononucleotide and flavin adenine dinucleotide, cofactors for many enzymes in intermediary metabolism
Deficiency:
Economically deprived developing countries
Alcoholism, chronic infections, adv. cancer, anorexia, avoid milk
symptoms:
Ariboflavinosis, cheliosis, stomatitis, glossitis, dermatitis, corneal vascularization
Niacin (vitamin b3)
Source: grain, legumes, seed oil; unabsorbable in corn; endogenously from tryptophan
Function: Incorporated into NAD and NAD phosphate, involved in redox reactions
Deficiency:
Pellagra: Dementia, dermatitis (bilateral, symmetrical, skin exposed to sun), diarrhea (atrophy of columnar epithelium in GI tract)
Vitamin B6 (pyridoxine)
Occurs in over half of alcoholic patients, rare in non-alcoholics
Function:
Derivatives serve as coenzymes in many intermediary reactions
Deficiency: cheilosis (cracks at angle of mouth), glossitis (atrophic tongue), dermatitis, peripheral neuropathy
Maintenance of myelinization of spinal cord tracts
Vitamin B12 (cobalamin) function deficiency causes symptoms eti
Function: Normal folate metabolism and DNA synthesis
Deficiency causes:
Megaloblastic pernicious anemia and degeneration of posterolateral spinal cord tracts
Symptoms:
Areflexia
Neuropathy
Causes: Impaired absorption Gastrectomy (stomach removed) Ileal resection Competition from tapeworms Vegetarianism
Folate (B9) source, function, cause, deficiency causes:
Source: whole wheat, beans, leafy, fortified in flour
Function:
Transfer and use of one-carbon units in DNA synthesis
Cause: Inadequate intake malabsorption increased losses hemodialysis (kidney failure)
Deficiency:
Megaloblastic anemia (more rapid than b12), neural tube defects (increase requirements in pregnancy)
Acute and chronic glossitis
Zinc
Function:
Components of enzymes, principally oxidases
Deficiency: inadequate supplementation in artificial diets
Interference with absorption by other dietary factors
Inborn error of metabolism
Rash around eyes, mouth, anus Anorexia and diarrhea Growth retardation in children depressed mental function Depressed wound healing/immune Impaired night vision Infertility
Iron
Most common nutritional disorder (inadequate hemoglobin synthesis)
Sources: meats, fortified flours and grains
Function
Essential component of hemoglobin as well as metalloenzymes
Deficiency:
Inadequate diet
Chronic blood loss
Hair loss Pallor Increasing fatigue Exertional dyspnea, tachycardia Pale mucous membranes Spoon shaped nails (koilonychia) Hypochromic microcytic anemia
Wernicke encepaholapthy
Acute thiamine deficiency
Generally reversible with large doses of thiamine
Confusion, nystagmus (uncontrolled eye movements), opthalmoplegia (paralysis), ataxia, short term memory loss, death
Korsakoff Psychosis
Permanent brain damage
Supplementing with thiamine will not affect
Loss of memory for distant events, inability to form new memories, loss of insight, intuition
Demyleination of limbic system
Megaloblastic Anemia
Abnormally large RBCs
Impairment of DNA synthesis
2 types: pernicious anemia (major form of B12 deficiency anemia)
Folate deficiency anemia (B9)
Body usage of Thiamine
Body has 18 days of thiamine stores
Thiamine is converted to active form in glial and neuronal cells
coenzyme for biochem pathways in brain
glucose metabolism
Enzymes:
A ketoglutarate dehydrogenase
pyruvate dehyrdrogenase
transketolase
