Flashcards in Nutrition Deck (48):
Th WHO definition of moderate stunting is measured through what parameter and what cut-off value?
Z-score below median HFA
severe stunting: zscore < -3
Useful for assessing the nutritional status of populations, because this measure of skeletal growth reflects the cumulative impact of events affecting nutritional status that result in stunting and is also referred to as chronic malnutrition
Height for age
What is the measure of acute malnutrition (wasting)?
weight for height (WFA)
NOT weight for age, which is an additional commonly used measurement of nutritional status (easier to measure, butcombines stature with current health conditions)
In emergencies and in some field settings, mid-upper arm circumference (MUAC) is often used for screening in lieu of weight for height.
Type of malnutrition characterized by failure to gain weight and irritability, followed by weight loss and listlessness until emaciation results
Nonedematous malnutrition (marasmus)
Syndrome that complicates the acute nutritional rehabilitation of children who are undernourished, marked by the development of severe hypophosphatemia after the cellular uptake of phosphate during the 1st week of starting to refeed
- Serum phosphate levels of ≤0.5 mmol/L can produce weakness, rhabdomyolysis, neutrophil dysfunction, cardiorespiratory failure, arrhythmias, seizures, altered level of consciousness, or sudden death
- prior to refeeding, get baseline K, Ca, Mg, PO4
How is pediatric obesity defined?
for children > 2y/o, obesity is defined as a BMI >= 95th percentile
overweight: BMI between 85-95th percentile
For obese children, when should bariatric surgery be considered?
surgery should be considered only in children with complete or near-complete skeletal maturity, a BMI ≥40, and a medical complication resulting from obesity, after they have failed 6 mo of a multidisciplinary weight management program
Name the vitamin deficiency based on the symptoms below:
poor overall growth, diarrhea, susceptibility to infections, anemia, apathy, mental retardation, and increased intracranial pressure, with wide separation of the cranial bones at the sutures
Vitamin A deficiency
night blindness - when vitamin A deficiency is more advanced, due to the absence of retinal in the visual pigment, rhodopsin, of the retina
xerophthalmia - cornea keratinizes and becomes opaque
Bitot spots - conjunctiva keratinizes and develops plaques
What are the three useful indicators of marginal vitamin A status?
conjunctival impression cytology
relative dose response
modified relative dose response
Patient was brought in with the following symptoms: headache; vomiting; anorexia; dry, itchy desquamating skin; seborrheic cutaneous lesions; fissuring at the corners of the mouth; alopecia and/or coarsening of the hair; bone abnormalities; swelling of the bones; enlargement of the liver and spleen; diplopia; increased intracranial pressure; irritability; stupor; limited motion; and dryness of the mucous membranes.
Radiographs show hyperostosis affecting several long bones, especially in the middle of the shafts
What should you consider?
acute hypervitaminosis A toxicity
Symptoms include nausea, vomiting, and drowsiness; less-common symptoms include diplopia, papilledema, cranial nerve palsies, and other symptoms suggesting pseudotumor cerebri
Rare autosomal recessive disorder characterized by megaloblastic anemia, diabetes mellitus, and sensorineural deafness, responding in varying degrees to thiamine treatment
Thiamine-responsive megaloblastic anemia (TRMA) syndrome
Patient on a diet consisting nostly of polished rice was brought in for consult due to the ff symptoms: peripheral neuritis (manifesting as tingling, burning, paresthesias of the toes and feet), decreased deep tendon reflexes, loss of vibration sense, tenderness and cramping of the leg muscles, congestive heart failure, and psychic disturbances.
What is your initial impression.
thiamine deficiency (beriberi)
Patient has the following complaints: Hoarseness or aphonia, ptosis, muscle atrophy and tenderness of the nerve trunks followed by ataxia, loss of coordination, and loss of deep sensation
What should you consider?
- Hoarseness or aphonia caused by paralysis of the laryngeal nerve is a characteristic sign
What are the two clinical types of thiamine deficiency?
dry (neuritic) type and a wet (cardiac) type
- Many cases of thiamine deficiency show a mixture of the 2 main features and are more properly termed thiamine deficiency with cardiopathy and peripheral neuropathy.
What is the classic clinical triad of Wernicke encephalopathy? What is the vitamin deficiency associated with this disorder?
mental status changes, ocular signs, ataxia
Thiamine deficiency (Vitamin B1)
What is the most common cause of death in patients with thiamine deficiency?
initial signs are slight cyanosis and dyspnea, but tachycardia, enlargement of the liver, loss of consciousness, and convulsions can develop rapidly. The heart, especially the right side, is enlarged and dilated; fatty degeneration of the myocardium is common.
What are the biochemical markers diagnostic of thiamine deficiency?
LOW erythrocyte transketolase activity (ETKA) and the HIGH thiamine pyrophosphate effect (TPPE).
What are the symptoms of dry beriberi (neuritic type)?
Irritability, peripheral neuritis, muscle tenderness, ataxia
What are the symptoms of wet beriberi (cardiac type)?
tachycardia, edema, cardiomegaly, cardiac failure
A malnourished child came in with the following symptoms: glossitis, photophobia, lacrimation, corneal vascularization, poor growth, cheilosis
What vitamin deficiency should you suspect?
riboflavin (vitamin b2)
riboflavin deficiency are mainly related to malnourished and malabsorptive states, including GI infections. Treatment with some drugs, such as probenecid, phenothiazine, or oral contraceptives, can also cause the deficiency
clinical features: cheilosis, glossitis, keratitis, conjunctivitis, photophobia, lacrimation, corneal vascularization, and seborrheic dermatitis
diagnosis is based on the clinical features of angular cheilosis in a malnourished child, which responds promptly to riboflavin supplementation
Associated vitamin deficiency with the ff symptoms: Pellagra manifesting as diarrhea, symmetric scaly dermatitis in sun-exposed areas, and neurologic symptoms of disorientation and delirium (dermatitis, diarrhea, dementia)
Niacin (vitamin B3) deficiency
- caused by predominantly maize-based diets, anorexia nervosa, carcinoid syndrome
Associated vitamin deficiency with the ff symptoms: Irritability, convulsions, hypochromic anemia, failure to thrive, oxaluria
pyridoxine deficiency (vitamin B6)
- usually caused by prolonged treatment with INH, penicillamine, OCPs
Associated vitamin deficiency: Scaly periorificial dermatitis, conjunctivitis, alopecia, lethargy, hypotonia and withdrawn behavior, usually caused by consumption of raw eggs for prolonged periods, parenteral nutrition with infusates lacking this vitamin, valproate therapy
*Avidin found in raw egg whites acts as a biotin antagonist.
Associated vitamin deficiency: irritability, fatigue, numbness, paresthesias (burning feet syndrome), muscle cramps; Isolated deficiency extremely rare in humans
Pantothenic acid (vitamin B5)
Associated vitamin deficiency: Megaloblastic anemia, growth retardation, glossitis, neural tube defects in progeny; usually caused by malnutrition, malabsorptive states, malignancies, hemolytic anemias, anticonvulsant therapy
Folic acid deficiency
Associated deficiency: Megaloblastic anemia, irritability, developmental delay, developmental regression, involuntary movements, hyperpigmentation; usually caused by vegan diets, malabsorptive states, Crohn disease, intrinsic factor deficiency (pernicious anemia)
Cobalamin (vitamin B12)
Pellagra is associated with what vitamin deficiency? Define the classic clinical triad of pellagra
Niacin deficiency (vitamin B3)
dermatitis, diarrhea, dementia
occurs chiefly in populations where corn (maize), a poor source of tryptophan, is the major foodstuff
Sharply demarcated lesions around the neck associated with niacin deficiency
The lesions first appear as symmetric areas of erythema on exposed surfaces, resembling sunburn, and might go unrecognized. The lesions are usually sharply demarcated from the surrounding healthy skin, and their distribution can change frequently.
Persons on a strict vegetarian/vegan diet, those who have pernicious anemia or Crohn's disease and pxs who underwent ileal resection are typically at risk for developing what vitamin deficiency?
Vitamin B12 (Cobalamin)
- Dietary sources of vitamin B12 are almost exclusively from animal foods
A disease of growing bone that is due to unmineralized matrix at the growth plates and occurs in children only before fusion of the epiphyses
- Osteomalacia is present when there is inadequate mineralization of bone osteoid and occurs in children and adults.
The following radiographic findings are characteristic of which vitamin deficiency?
- shafts of the long bones have a ground-glass appearance due to trabecular atrophy
- pencil outlining of the diaphysis and epiphysis
- subperiosteal hemorrhages
- white line of Frankel
- Trumerfeld zone
- Pelkan spur
Scurvy (vitamin C deficiency)
white line of Frankel - an irregular but thickened white line at the metaphysis, represents the zone of well-calcified cartilage
Trumerfeld zone- zone of rarefaction, a linear break in the bone that is proximal and parallel to the white line, represents area of debris of broken-down bone trabeculae and connective tissue
Pelkan spur- a lateral prolongation of the white line and may be present at cortical ends.
Which vitamin deficiency should be suspected with the following classic clinical signs:
enlargement at the wrists and ankles
Vitamin D deficiency (rickets)
- rachitic rosary - results from the widening of the costochondral junctions
- enlargement at the wrists and ankles - due to growth plate widening
- Harrison groove - horizontal depression along the lower anterior chest, results from pulling of the softened ribs by the diaphragm during inspiration
How is vitamin D deficiency diagnosed?
Most are diagnosed based on the presence of classic radiographic abnormalities, supported by PE findings
The child with rickets has metaphyseal fraying and cupping of the distal radius and ulna.
What is the most important source of vitamin D?
the skin (cutaneous synthesis)
What vitamin deficiency may result in children receiving anticonvulsants such as phenobarbital or phenytoin or antituberculosis medications such as isoniazid or rifampin?
Vitamin D deficiency (rickets)
- these drugs induce cytochrome P450 in the liver, which increases the degradation of vitamin D
An autosomal recessive disorder with mutations in the gene encoding renal 1α-hydroxylase, preventing conversion of 25-D into 1,25-D
Vitamin D dependent Rickets Type 1
- since 1α-hydroxylase is not present, 1,25-D cannot be produced, leading to decreased absorption of Ca in the gut
Patients with this type of rickets have mutations in the gene encoding the vitamin D receptor, preventing a normal physiologic response to 1,25-D
Vitamin D-dependent rickets, Type 2
Type 1- no enzyme that converts 25-D to 1,25-D, which promotes Ca absorption
Type 2 - receptors for 1,25-D are defective, normal response not attained
Which population is particularly at risk for vitamin E deficiency?
- Vitamin E deficiency in premature infants causes thrombocytosis, edema, and hemolysis potentially causing anemia
- risk increased by use of preterm formulas containing high PUFAs and aggressive use of iron, which can lead to further oxidative stress
What are the symptoms of vitamin E deficiency?
in patients with prolonged vitamin E deficiency, a severe, progressive neurologic disorder occurs
- symptoms occur only after 1 yr old
- may have cerebellar disease, posterior column dysfunction, and retinal disease
- initial finding : loss of DTRs
- in premature infants, vitamin E deficiency causes hemolysis usually on the 2nd month
What vitamin deficiency should be screened in children with unexplained ataxia?
consider AVED (ataxia with isolated vitamin E deficiency)
- Patients with this disorder are unable to incorporate vitamin E into lipoproteins before their release from the liver, leading to reduced serum levels of vitamin E
- no symptoms of malabsorption
- diagnose with high index of suspicion
What are the two types of vitamin K?
Vitamin K1 - phylloquinone (plant based)
Vitamin K2 - menaquinone (produced by intestinal bacteria)
What are the classic Gla-containing proteins involved in blood coagulation that are decreased in vitamin K deficiency?
(Gla - carboxyglutamate)
Factors II (prothrombin), VII, IX, X, protein C, S, and Z
3 forms of VKDB (vit K dependent bleeding) of the newborn?
1. Early VKDB, formerly classic hemorrhagic disease of the newborn (occurs 1-2 wks of age)
2. Late VKDB - 2-12 wks of age
3. VKDB due to maternal medications - occurs at birth, eg maternal use of phenobarbital, phenytoin, and warfarin may cause bleeding bec it crosses placenta and interferes with vit K function
What is the lab parameter being monitored in the correction of vitamin K deficiency?
- PT should decrease in the first 6 hrs after treatment and normalize in 24 hrs
- PTT may be prolonged, but may be normal in the early stage of the disease
- PIVKA-II (proteins induced by vitamin K absence) can be measured to detect mild vit K deficiency
What is the known effect of dietary selenium deficiency?
Cardiomyopathy (Keshan disease)
Menkes disease is associated with what trace element deficiency?
- due to a mutation in the gene coding for a protein that facilitates intestinal copper absorption
- results in severe copper deficiency
Patients with the recessive disorder acrodermatitis enteropathica will need this trace element supplementation
- the disorder is secondary to malabsorption if zinc