24) Nutrition & vitamins Flashcards
Major components of energy output
Resting Energy Expenditure (REE)
physical activity
Average energy intake
American women is approximately 1800 kcal/d
American males is approximately 2600 kcal/d
Recommended dietary allowance (RDA) for protein
approximately 0.6 g/kg body mass per day
Dietary requirements for a healthy diet are ——% of calories from protein.
10-15
Contribution of carbohydrates to total caloric intake should be at least ——–%.
45-55
Brain requires approximately —– g/dL carbohydrate in order to function properly.
100
Benchmark recommendations for nutrient intakes developed to guide clinicians.
Replaced RDA
Dietary Reference Intakes (DRI)
DRI includes ———— for protein, fat, and carbohydrates
acceptable macronutrient distribution ranges (AMDRs)
Science of measuring the human body
Anthropometry
Anthropometry includes…
Craniometry
Osteometry
Skin-fold evaluation for subcutaneous fat estimation
Height and weight measurements
BMI
Body mass index < ——– and/or recent loss of ≥ ——- of usual body mass puts pt at risk for nutritional deficiency
18.5
10%
Hypermetabolic states
sepsis, protracted fever, extensive trauma or burns
serum albumin RR
3.5-5.0 g/dL
Serum prealbumin (transthyretin) RR
20-40 mg/dL
TIBC RR
240-450 ug/dL
Prolonged shows Vitamin K deficiency
PT
>15.5 sec
—– mg/dL serum creatinine reflects muscle wasting
< 0.6
24hr urine creatinine RR
500-1200 mg/d
reflects catabolism
Levels of >15 g/d severe catabolism
24 hr urinary urea nitrogen (UUN)
Protein Balance = Protein Intake - Protein Loss, where protein loss (protein catabolic rate) =
[24h UUN (g) + 4] x 6.25
——- mg/dL BUN = inadequate protein intake
< 6 mg/dL
adequate intake: 12-20 mg/dL
2 reasons for providing specialized nutrition support (SNS)
- Provide appropriate nutritional substances to maintain or replenish the nutritional status of patients unable to voluntarily ingest or absorb sufficient amounts of food
- Maintain the nutritional and metabolic status of sufficiently nourished patients who may have a health issue such as severe inflammation, injury, or infection
TPN
Direct infusion of complete mixtures of crystalline amino acids, dextrose, triglyceride emulsions, and micronutrients into the circulatory system through a central venous catheter.
TPN should be considered if…
energy intake has been or is anticipated to be inadequate for more than 10 days and enteral feeding is not feasible
3 techniques for functional/indirect vitamin assays
- Increased or decreased activity of reactions
- Cell response to inhibitors
- Activators that will reflect alteration in vitamin concentrations
direct vitamin assays
Immunoassays, colorimetric, fluorescent, separation techniques, spectrophotometers, fluorometers, gas and liquid chromatographs, and mass spec.
Erythrocyte transketolase activation
B1/thiamine
Thiamine concentration in blood as thiamine pyrophosphate
B1/thiamine
Measure F A D-dependent glutathione reductase activity in freshly lysed erythrocytes
B2/riboflavin
(1) Measure two urine metabolites, Nmethyl nicotinamide and ‘N-methyl-2-pyridone-5’carboxyamide
(2) Determine ratio of
N A D/N A D P in erythrocyte and plasma tryptophan
B3/niacin
Measure activity of erythrocytes
B6/pyridoxine
Measure plasma levels of pyridoxal-5-phosphate
B6/pyridoxine
(1) Urine and serum concentration of methylmalonic acid
(2) Plasma homocysteine
(3) Deoxyuridine suppression test
(4) Vitamin absorption test
B12
(1) Plasma vitamin level
(2) Retinol binding protein using radial immunodiffusion or nephelometry
vitamin A
(1) Protection of erythrocyte hemolysis on addition of peroxides
(2) Inhibition of lipid peroxidation products
vitamin E
(1) Serum alpha-tocopherol
(2) In tissue (lymphocytes, platelets, or red blood cells)
vitamin E
(1) Prothrombin clotting time
(2) Immunoassay of γ-carboxy prothrombin or undercarboxylated prothrombin
(3) Plasma undercarboxylated osteocalcin
vitamin K
Plasma phylloquinone
vitamin K
Urine samples are not useful in some conditions because most vitamins are not…
under homeostatic control
Coenzyme for cleaving carbon-carbon bonds
B1/thiamine
Beriberi
B1/thiamine
Cofactor for oxidation, reduction reactions
B2/riboflavin
B3/niacin
Seborrhea, magenta tongue
B2/riboflavin
Pellagra: pigmented rash of sun-exposed areas, reddish tongue
B3/niacin
Component of Acetyl CoA
B5/pantothenic acid
Cofactor for enzymes of amino acid metabolism
B6/pyridoxone
Hypophosphatasia, glossitis, seborrhea, neuropathy, microcytic anemia
B6/pyridoxone
Coenzyme for several carboxylases
B7/biotin
Scaly dermatitis, glossitis, hair loss, anorexia, depression, and hypercholesterolemia
B7/biotin
Coenzyme for methionine synthase and l-methylmalonyl CoA mutase
B12
Megaloblastic anemia, dementia, increased homocysteine and methylmalonic acid
B12
folate
Coenzyme for one carbon transfer in nucleic acid and amino acid metabolism
folate
Participation as a redox ion in several biological oxidation and hydrogen transfer reactions
vitamin C
petechiae, ecchymosis, inflamed and bleeding gums
vitamin C
scurvy
Formation of rhodopsin and glycoproteins
vitamin A
Nightblindness, follicular hyperkeratosis, xerophthalmia
vitamin A
Hormone that controls calcium and phosphorus metabolism
vitamin D
Antioxidants
vitamin E
Peripheral neuropathy, skeletal muscle atrophy, retinopathy
vitamin E
Cofactor for posttranslational carboxylation of many proteins and clotting factors
vitamin K
Mostly found in yellow to orange pigmented fruits and veggies
carotene/previtamin A
Most active form of carotenoid found in plants
B-carotene
Nyctalopia
night blindness
vitamin A deficiency
Bitot’s spots
small gray plaques with foamy surfaces
vitamin A deficiency
rickets
vitamin D
A peroxyl radical scavenger that protects LDL and polyunsaturated fats in membranes from oxidation
vitamin E
- Enhancing immune function
- Blocking formation of nitrosamine (known carcinogen)
- Delaying the development of coronary artery disease
Vitamin E
(controverial, not proven)
causes of vitamin E deficiency
- Premature birth
- Malabsorption of dietary fat
- Rare disorders of fat metabolism
may reduce platelet aggregation and thus interfere with Vitamin K metabolism
patient on ——— should not over-supplement
vitamin E
warfarin
Green vegetables, plant oils, margarines, cheese, eggs, and other milk products
vitamin K
causes of vitamin K deficiency
May develop from taking anticoagulants and antibiotics
Early deficiency: Anorexia and nonspecific symptoms
B1/thiamine
Wet beriberi:
Dry beriberi:
Cardiovascular symptoms
Peripheral neuropathy
Wernicke-Korsakoff Syndrome
Central nervous system complication that develops in alcoholics with thiamine deficiency
lesions of the mucocutaneous surface of the mouth and skin
B2/riboflavin
Occurs in individuals whose diets consist mainly of corn-based foods in China, Africa, and India
In the United States, occurs in alcoholics and in patients with carcinoid tumors
pellagra (niacin def)
Bright red tongue, Casal’s necklace (skin rash), loss of appetite, generalized weakness and irritability
pellagra (niacin def)
Tetrapyrrole ring surrounding cobalt atoms.
B12
Progressive swelling of myelinated neurons, demyelization, and neuronal cell death in the spinal column and cerebral cortex
B12 def
Kidney stones made of oxalic acid
vitamin C overdose
