Chapter 9 nutrition and nutraceuticals Flashcards
Influences of food on bioavailability
- presence of food influences absorption (no food slows, too much food slows, fatty foods increase)
- gastric pH influences absorption
- chemical interactions between drug and specific foods ( i.e. Tetracycline, phenytoin)
Bioavailability
Percentage of drug available to produce pharmacological effect
CYP450
major grp. responsible for metabolizing foreign chemicals
-rate of drug metabolism influenced by nutrient intake
adverse reaction of grapefruit juice on CYP3A4
-can increase levels of: calcium channel blk cyclosporins tacrolimus statins
Drug-induced nutrient depletion
- drugs can induce or inhibit metabolic processes affecting nutrient metabolism/bioavailability
- i.e. loop diuretic leading to depletion of electrolytes and eventually malabsorption
- i.e. phenytoin inhibits intestinal enzymes absorbing folic acid
Populations needing nutritional supplementation per ADA:
infants/children-400IU vit D/day
women 400 mcg/day folic acid
pregnant women 600 mcg/day folic acid, multi-vitamin, iron,B12
pt.>50y B12, vit D, calcium
Nutraceuticals
foods claiming to have medicinal effects on health
5 categories; dietary fiber, vitamins and minerals, biactive substances, fatty acids, pre-pro-and symbiotics
Vitamin A
- role in vision, bone growth, reproduction, immune function
- deficiency seen in developing countries and chronic ETOH abuse
- supplement decreases bronchopulmonary dysplasia in low birth weigh infants
Vitamin B1 thiamine
deficiencies lead to beriberi and Wernicke’s encephalopathy
-ETOH abusers at higher risk for encephalopathy
vitamin B2 riboflavin
- deficiency rare but ETOH abusers, anorexics, and those who are lactose intolerant at risk
- can decrease head aches and migraines
Vitamin B3 niacin
- deficiency aka pellagara due to inadequate intake
- can be treatment for hyperlipidemia
Vitamin B6 pyridoxine
- needed for protein, red blood cell metabolism, glucose regulation
- deficiency may be drug induced by isoniazid, cycloserine, or hydrazine-can be given prophylactically if on these meds to prevent neuropathy
- intake can be increased by fortified cereals, potatoes, bananas, meat
Vitamin B12
- essential in red blood formation and neurological function
- deficiency leads to megaloblastic anemia, fatigue, loss of appetite, neurological changes
- recommended dose: 2.4 mg/day for older adults
vitamin C ascorbic acid
- deficiency causes scurvy
- decreased in smokers
- populations at high risk are infants fed evaporated milk or boiled milk, those with malabsorption disorders and end stage renal patients on dialysis
Vitamin D
- available in some food-egg yolks and fatty fish
- needed for calcium absorption and regulates calcium and phos levels (calcitriol)
- deficiencies lead to rickets (kids) and osteomalacia (adult)
- recommended dose: 400 IU daily
vitamin K
- component of blood clotting
- new borns high risk of deficiency-usually give IM injection within 24 hours of birth-2 weeks
- warfarin interferes with vit. K
Folate
- needed for production and maintenance of new cells
- found in foods-green leafy veggies, citrus fruits, dried legumes
- increased demand for pregnant women
- meds that interfere with absorption: antiepileptics, metformin, methotrexate, barbiturates, oral contraceptives, isoniazid
- deficiencies lead to macrocytic-normochromic anemia
- recommended dose: 400 mcg/day females of child bearing age; 600 mcg/day for pregnant women; 500 mcg/day for lactating women
calcium
- needed for muscle contractions, blood vessel health, bone health, and nerve conduction-decreased amounts leads to tetany
- at risk populations-postmeno women, amenorrheic women, women with female athlete triad, lactose intolerant
iron
- needed for regulation of cell growth and differentiation, and o2 transport
- deficiency leads to microcytic-hypochromic anemia (IDA)
- recommended dose: 27 mg/day for pregnant women
fatty acids
- needs to be consumed (body can not produce)-nuts, veg. oils, leafy greens, and meats
- fish oil-reduces mortality in CAD pts.
- omega 3 decreases triglyceride levels in DM pts, and essential in central nervous development in infants-may have link to autism and ADHD
plant sterols
- associated reduction of LDL especially in conjunction with low-chol. diet and medication
- present in edible oils, seeds, nuts and added to margarine, orange juice,
pre-,pro, symbiotics
probiotics nonpathogenic bacteria found in intestinal microflora-lactobacillus acidophilus and bifidobacterium
prebiotics-nondigestable food ingredients that stimulate growth of probiotic organisms
symbiotics are combination of both
-probiotics reduce antibiotic-assoc. diarrhea in adults, improves IBS or necrotizing enterocolitis, prevents NEC and death in preterm infants
foods and CYP1A2
- can lead to therapeutic failure
i. e. low potassium and high carbohydrates effect metabolizing enzymes
influence on diet on drug excretion
- some foods can change urinary pH drug excretion
i. e. foods that make more alkaline: milk, veggies, citrus fruits
i. e. foods that make more acidic: meats, fish, eggs
