CHAPTER 10 HUMAN NUT - Sheet1 Flashcards
(40 cards)
What are the potential hazards associated with supplement use, according to the passage?
Supplement users may face excessive intakes of certain nutrients, and the extent and severity of supplement toxicity remain unclear. Large doses may be toxic, as seen in the example of selenium supplements.
Why is chronic supplement toxicity often unrecognized and unreported?
Chronic supplement toxicity often goes unrecognized because the effects develop subtly and progress slowly. Only a few health-care professionals can recognize it.
What are the life-threatening consequences of overdoses of iron supplements in children?
Iron supplements (30 milligrams of iron or more per tablet) are especially toxic and can cause fatalities among children. Even mild overdoses cause GI distress, nausea, and black diarrhea, reflecting gastric bleeding.
According to the passage, why might people with illnesses turn to high doses of vitamins or minerals, and what risks are associated with this behavior?
People with illnesses might believe that high doses of vitamins or minerals can be therapeutic, potentially leading them to avoid seeking medical help. However, high doses can be toxic, and there are no guarantees that the supplements will be effective.
What are some arguments against the use of supplements mentioned in the passage?
Arguments against supplement use include the lack of standards for formulating the “ideal” supplement, a false sense of security leading to irresponsible eating, and the belief in invalid reasons such as inadequate nutrients in the food supply.
What is the role of antagonistic actions in the context of supplement use? Give examples mentioned in the passage.
Antagonistic actions involve factors that counteract the action of another factor. Examples include zinc hindering copper and calcium absorption, iron hindering zinc absorption, and vitamin A precursor beta-carotene interfering with vitamin E metabolism.
What criteria does the passage suggest for selecting a vitamin-mineral supplement?
The criteria for selecting a supplement include looking for a single, balanced vitamin-mineral supplement with a USP verification logo, indicating testing for ingredient accuracy, contaminant levels, and disintegration time.
What are some misleading claims and marketing tricks associated with supplement products, as discussed in the passage?
Misleading claims include high potency claims, the idea that natural supplements are more effective, and claims that supplements can relieve stress. Marketing tricks involve “green” pills and the use of nanotechnology.
How are dietary supplements regulated, and what limitations exist in their regulation according to the passage?
Dietary supplements are regulated by the FDA under the Dietary Supplement Health and Education Act of 1994. However, the act resulted in deregulation, as supplements do not need to be proved safe and effective before marketing.
Why does the passage argue that foods are a better source of nutrients than dietary supplements?
The passage argues that foods offer a variety of nutrients in complex combinations, along with water, fiber, and phytochemicals. Foods stimulate the GI tract, provide energy, and meet human health needs better than dietary supplements.
What are the three forms of Vitamin and how are they converted to the active coenzyme PLP?
Three forms of Vitamin : Pyridoxal, Pyridoxine, Pyridoxamine. They are converted to the coenzyme PLP (pyridoxal phosphate) by the body.
Describe the role of PLP in various metabolic reactions mentioned in the passage.
Role of PLP: PLP is active in more than 100 reactions, including carbohydrate, fatty acid, and amino acid metabolism.
Explain how PLP is involved in the synthesis of nonessential amino acids and the conversion of tryptophan to niacin or serotonin.
PLP’s Role in Amino Acids: PLP is used to transfer amino groups, enabling the body to make nonessential amino acids. It is crucial in the conversion of tryptophan to niacin or serotonin.
What are the early symptoms of Vitamin deficiency, and how does alcohol contribute to its destruction in the body?
Early Symptoms of Vitamin Deficiency: Depression, confusion. Alcohol contributes to Vitamin destruction by producing acetaldehyde, which dislodges PLP from its enzymes.
Discuss the major report on Vitamin toxicity in the early 1980s and the consequences of consuming large doses.
Vitamin Toxicity: Neurological damage reported with doses exceeding 2 grams daily for 2 months or more.
Identify the food sources of Vitamin , and explain the impact of heating on its bioavailability.
Vitamin Food Sources: Meats, fish, poultry, potatoes, fruits. Heat leads to the loss of Vitamin .
Define folate, its coenzyme forms, and its primary role in metabolism according to the passage.
Folate and Coenzyme Forms: Folate, also known as folic acid, has coenzyme forms DHF and THF, essential for amino acid conversions and DNA synthesis.
Describe the process of folate absorption, activation, and its relationship with Vitamin .
Folate Absorption and Activation: Folate is absorbed, activated by removing a methyl group with Vitamin , and stored in the liver. GI tract injuries can lead to folate loss.
Explain the vulnerability of the folate-handling system in the GI tract, especially in cases of alcohol abuse.
GI Tract Vulnerability: Folate deficiency develops in alcohol abuse, damaging the GI tract and affecting cell multiplication.
Why is folate supplementation crucial for women of childbearing age, and what role does it play in preventing neural tube defects?
Folate in Pregnancy: Folate prevents neural tube defects. Pregnant women need higher folate intakes.
Discuss the safety concerns related to folate fortification and its potential impact on masking vitamin deficiencies.
Folate Fortification Concerns: Safety concerns due to masking vitamin deficiencies. Debates on risks and benefits of folate fortification.
Explore the connection between folate, heart disease, and cancer based on the information in the passage.
Folate and Heart Disease: Folate breaks down homocysteine, linked to heart disease. However, its impact on reducing heart attack risk is debated.
What are the symptoms of folate deficiency, and how does it affect cell division and protein synthesis?
Symptoms of Folate Deficiency: Macrocytic or megaloblastic anemia, GI tract deterioration.
Highlight the interactions between folate and certain drugs, and how they can lead to a secondary deficiency.
Folate-Drug Interactions: Certain medications, like anticancer drugs, can displace folate and interfere with normal metabolism.
