Food/Dietary Supplements Flashcards
What organization defined “Dietary Supplement”? (read)
DHSEA act
DHSEA Criteria for a “dietary supplement”? (read)
a. A product (other than tobacco) intended to supplement the diet that contains one or more of the following ingedients: a vitamin, mineral, herb/botanical, amino acid. b. Taken to supplement the diet by increasing total daily intake, or a concentrate, metabolite, constituent, extract, or combination of these. c. Intended for ingestion (pill, capsule, tablet, liquid) d. Not represented for use as a conventional food or as the sole item of a meal or diet. d. Labeled as a “dietary supplement”
Labeling issue w/ dietary supplements? (read)
Multiple ingredients, each containing multiple pharmacologically active components. Their composition may vary by geographical area, by season, or by method of processing.
Critical issues when considering consumption of dietary supplements? (read)
- Consult healthcare provider before taking a dietary supplement for a self-dx’d condition 2. Don’t mix supplements and prescription drugs w/out healthcare provider’s approval 3. Check w/ healthcare provider if you are scheduled to have any type of surgery 4. “Natural” does not always mean safe
Trends in consumption of vitamins and herbal products (dietary supplements)? (3)
- Supplement consumption > vitamin consumption 2. Use and sale of supplements and vitamins continues to increase each year 3. Women are more likely than men to take either
What is driving the increase in sales/use of supplements in US?
Supplements are perceived as less costly alternatives to traditional prescription drugs and doctor visits
Most common reasons consumers take supplements? (6)
Wt loss = Heart problems > Digestion > Pain > Seasonal allergies > Diabetes
This reflects the incidence of these ailments in the general population
What is a problem healthcare providers face in accurately determining the consumption of herbal products or supplements among patients? Example?
The general public may not immediately recognize that something is a supplement and assume b/c herbals are “natural” they are safe, which is a misguided belief Ex: St John’s Wort Tea– made by respected companies, found in local supermarket
DSHEA Legislation of dietary supplements?
- Good Manufacturing Process standards 2. Manufacturers, packers, and distributors MUST report serious adverse events associated w/ their product to the FDA, making it possible to identify trends in adverse effects and alert the public to safety/health issues
Fundamental difference b/t FDA regulation of drug approval and herbal products/supplements? Role of FDA vs manufacturer?
FDA requires manufacturers of drugs to prove they are effective and safe. FDA has no such controls over herbs/supplements b/c they are regulated by the FDA as foods. For herbs/supplements, the manufacturer is responsible for ensuring the product is safe before marketed. FDA is only responsible for stepping in/taking action against supplements found to be unsafe after they reach the markets.
Problems w/ herbals/supplements not seen w/ medications?
With drugs, individual components are well established and their toxicities are understood. Supplemens: - active ingredient is often unknown, there can be dozens of active compounds in one supplement. - Contamination–either accidental (microorganisms, heavy metals) or deliberate (adulteration w/ unlabeled prescription drug products used to ensure activity; ie adulterated sex pills w/ lots of viagra)
Policy on supplement standardization in US?
Supplement standardization not required in US. No legal or regulatory definition of standardization as it applies to supplements, so on a label it can mean many different things, and does not necessarily indicate product quality. The term “Standardized” on a supplement’s label carries no implications regarding the quality of the product contained within.
Why do “natural” supplements not equal safe supplements? (4)
- Supplements can cause organ damage 2. Supplements can cause medical problems, esp if taken incorrectly or in large amounts, and sometimes even at recommended doses. 3. Teratogenic/Developmental effects–caution in Pregnancy and when using in kids 4. Interactions w/ prescription and OTC drugs Proper guidance is essential
Claims allowed by DSHEA on Labels of Supplements? (3)
- Health claims–relationship b/t dietary supplement ingredient and risk of disease or health condition 2. Nutrient content claims (free, high/low, reduced, lite) 3. Structure-function claims–manufacturer responsible for accuracy/truthfulness (folic acid reduced neural tube defects) With these claims, manufacturers must also say, “This statement has not been evaluated by the FDA. This product is not intended to diagnose, treat, cure, or prevent any disease.”
What group of patients is at especial risk from supplements? Why?
Pt’s scheduled to undergo surgery– b/c many supplements affect Platelet Aggregation and can cause HTN, bleeding, herb-drug interactions. Pt’s are recommended to cease an products at least 2 weeks before surgery.
Role of biotransformation of supplements?
P450 Metabolism (primarily in liver)
- Detoxification: CYP conversion to non-toxic prodcut, decreasing toxicity and carcinogenesis
- Intoxication: increase in toxicity due to metabolism. Covalent binding of reactive intermediates to cellular proteins/DNA, leading to toxicity via multiple mechanisms.
Ephedra use? What organ system is it toxic to?
Used for wt loss; causes CV toxicity–> arrhythmias and sudden cardiac death
Licorice use? toxicity?
Used for PUD and flavoring
Toxicity: Pseudohyperaldosteronism–> metabolite (glycyrhizzin) promotes salt and water retention despite normal aldosterone levels, leading to increased BP and adverse effects in pt’s being treated for HTN or other CV diseases
Herbals affecting coagulation status? (5 types, 3 specific examples)
- Natural coumarin derivatives
- Natural salicylates: Willowbark
- Antiplatelet effects: Garlic, Ginkgo Biloba
- Fibrinolytic action
- Interxns w/ coag cascade or warfarin anticoagulant
5 Herbs/supplements that have CYP interactions w/ prescription drugs? Enzymes involved?
BEGGS-
- Bitter Orange: inhibits CYP3A4
- Echinacea: inhibits 1A2, inhibits intestinal 3A4, induces 3A4
- Ginkgo Biloba: inhibits 1A2 & 2D6
- Ginseng: inhibits 2D6
- St Johns Wort: Induces 1A2, 3A4, 2C9
Bitter orange CYP interactions–Enzyme and Drugs?
Inhibits 3A4
What are 3 supplements that antagonize the actions of medications?
- Echinacea & Ginseng: antagonize immunosuppressants like azathioprine, corticosteroids, cyclosporine, and tacrolimus.
- Caffeine: stimulant effects may oppose sedatives and produce additive actions w/ epinephrine, phentermine, pseudoephedrine, nicotine, or amphetamine.
Vitamine facts? (3)
- Essential cofactors for many essential metabolic processes needed for growth, digestion, nerve function, etc.
- Water-soluble vs fat-soluble
- Water-soluble: easily absorbed; NOT stored in the body; renally eliminated
- Fat-soluble (ADEK): absorbed w/ bile acids; can be stored and accumulate in the body
What is a common misperception among consumers about vitamins? Example?
Like herbs, vitamins are perceived as healthy, so more/larger doses must make you even even healthier. Excess amounts can be bad.
Ex: Acute renal failure due to oxalate crystal deposition resulting from excessive Vit C consumption
