B2.027 Nutritional Deficiencies Flashcards
what are some major causes of malnutrition?
altered taste/smell nausea/vomiting diarrhea/malabsorption poor food quality/availability self imposed restrictions metabolic disturbances alcoholism cytokine effects liver disease unpalatable diets
how can alcohol intake cause malnutrition?
decreasing calorie intake interfering with nutrient digestion and absorption reduce protein synthesis and secretion causing breakdown of gut proteins increasing excretion of nutrients
what are physical exam findings of malnutrition?
weight loss, low BMI, loss of subcutaneous fat, loss of muscle mass, reduced handgrip strength
what is another name for vitamin A?
retinol
what are dietary sources of vitamin A?
preformed: liver, fish, eggs, milk
carotenoid precursors: yellow and leafy green veggies
what are signs of vitamin A deficiency?
night blindness, eye dryness, corneal ulceration, , perifollicular hyperkeratosis (small bumps on skin), and immune deficiency
can vitamin A build up to toxic levels?
yes
what are symptoms of acute vitamin A toxicity?
headache, vomiting, stupor, death
what are symptoms of chronic vitamin A deficiency?
weight loss, vomiting, dry lips, bone and joint pain
what is carotenemia?
excessive vitamin A precursors
is carotenemia associated w toxicity?
no
what are sources of vitamin D?
sunlight, fortified dairy products
what can cause vitamin D deficiency?
diets lacking in Ca and vitamin D, limited exposure to sunlight
what are signs of vitamin D deficiency?
rickets in children, osteomalacia in adults, bone pain, weakness of proximal muscles, hypocalcemia
what are important functions of vitamin C?
antioxidant and important in hydroxylation of procollagen
which disease is associated with vitamin C deficiency?
scurvy
characterized by bone disease in growing children and hemorrhages and healing defects in both children and adults
what are sources of vitamin C?
fruits and veggies
what are signs and symptoms of vitamin C deficiency?
weakness/fatigue aching bones/joints/muscles at night acne hair deformities easy bruising loss of teeth
what are functions of vitamin A?
component of visual pigment
maintenance of epithelia
maintenance of resistance to infection
what is the primary function of vitamin D?
facilitates intestinal absorption of calcium/phosphorous and mineralization of bone
what is the primary function of vitamin E?
major antioxidant
what is the primary function of vitamin K?
cofactor in hepatic carboxylation of procoagulants
what are the b-complex vitamins?
b1 (thiamine) b2 (riboflavin) b3 (niacin) b5 (pantothenic acid) b6 (pyridoxine) b7 (biotin) b12 folate
what are general properties of B vitamins?
water soluble, function as coenzymes (needs are tied to energy intake), present in fortified foods
what are signs of a b1 (thiamin) deficiency?
dry beriberi (CNS), wet beriberi (circulation), high output heart failure w tachy, elevated peripheral venous pressure, edema, peripheral neuropathy, WK syndrome
what are sources of b1?
whole grains
what are sources of b3 (niacin)?
grain, legumes, seed oils, made endogenously from tryptophan
what are signs of a b3 deficiency?
3 D’s dermatitis (skin affected by sun), dementia (atrophy of neurons), diarrhea (atrophy of columnar epithelium in GI)
what are sources of b2 (riboflavin)?
meat, dairy, veggies
what are signs of a b2 deficiency?
cheliosis/chelitis (cracks at angles of mouth)
glossitis (shiny tongue)
corneal opacities and ulcerations
dermatitis
what is a characteristic of populations affected by b6 (pyroxidine) deficiencies?
rare in nonalcoholics, present in over half of alcoholics
what is megaloblastic anemia?
anemia with abnormally large RBC, increased mean corpuscular volume
due to impairment of DNA synthesis which leads to ineffective hematopoiesis (blood cell formation)
what are the 2 types of megaloblastic anemia?
pernicious (b12 deficiency)
folate deficiency
what can cause b12 deficiency?
vegetarianism impaired absorption intrinsic factor def gastrectomy ileal resection competition from tapeworms
what is a major sign of b12 def?
pernicious anemia
caused by autoimmune gastritis that impairs production of intrinsic factor , which is required for b12 uptake from the gut
what secretes intrinsic factor?
parietal cells
what are sources of folic acid?
whole wheat flour, beans, green leafy veggies
what creates a folic acid def?
inadequate intake
malabsorption
increased losses
what is the difference between folate deficiency anemia and pernicious (b12) anemia?
indistinguishable but develops much more rapidly
body has less folate stores than b12
what is the relationship between folate and pregnancy?
requirements increase during pregnancy
deficiency can predispose to neural tube defects
what is the most common nutritional disorder in the world?
iron deficiency
inadequate hemoglobin synthesis
what are sources of iron?
meats (heme iron)
plants (non heme iron, require acid for absorption)
fortified flour/grains
what are signs of iron def?
pallor increasing fatigue exertional dyspnea, tachycardia pale mucous membranes spoon shaped nails
depict iron deficiency from a histology perspective
small RBC containing narrow rim of peripheral hemoglobin
normal RBC should be fully red
