Oxidants

What is the defining characteristic of a radical species?

Contain one or more orbital electrons with unpaired spin states

What type of compound promotes oxidation?

Pro-oxidant

What is the primary action of radical species?

Seek and 'steal' electrons from other molecules

What is the defining characteristic of a radical species?

It contains one or more orbital electrons with unpaired spin states Signup and view all the answers

What is the primary action of an oxidant?

Oxidizes other compounds Signup and view all the answers

What is the role of an antioxidant in oxidation reactions?

Inhibits/reverses oxidation Signup and view all the answers

What is the primary effect of radical species on cell proteins?

Causing damage to cell proteins Signup and view all the answers

Which condition is NOT associated with the potential roles of radical species mentioned in the text?

Common cold Signup and view all the answers

What is the impact of radical species on DNA?

Causing DNA mutations Signup and view all the answers

What is the primary function of antioxidants in the body?

Prevent oxidation by donating electrons to stabilize radical species Signup and view all the answers

Which of the following vitamins meets the definition of dietary antioxidants?

Vitamin C Signup and view all the answers

Why are carotenoids included in the discussion of antioxidants despite not meeting the definition of dietary antioxidants?

Because they influence oxidative processes Signup and view all the answers

Which of the following foods is NOT listed as a source of vitamin C in the text?

Apples Signup and view all the answers

What is the oxidized form of ascorbic acid referred to in the text?

Dehydroascorbic acid Signup and view all the answers

Why do smokers require more vitamin C according to the text?

Higher oxidative stress and metabolic turnover of vitamin C Signup and view all the answers

What is the primary function of vitamin C as an enzyme cofactor?

Regulating reactions requiring reduced metal ions and protein synthesis Signup and view all the answers

What is the impact of high concentration vitamin C intake on absorption?

Passive transport with less than 50% absorption Signup and view all the answers

What is the effect of time release dose compared to single dose on vitamin C absorption?

Higher net absorption Signup and view all the answers

What is the role of vitamin C in relation to radical species and antioxidants?

Scavenging radical species and regenerating other antioxidants Signup and view all the answers

What is the source of released vitamin C in reaction to stress?

Adrenal glands Signup and view all the answers

What is the primary role of vitamin C as an enzyme cofactor?

Assisting in collagen and connective tissue synthesis Signup and view all the answers

What is the impact of high concentration vitamin C intake on absorption?

Passive transport absorption decreases Signup and view all the answers

What is the key function of vitamin C's reducing power?

Acting as an effective antioxidant for scavenging radical species Signup and view all the answers

What is the impact of time release dose compared to a single dose on vitamin C absorption?

Higher net absorption with time release dose Signup and view all the answers

What is the role of released vitamin C in reaction to stress?

Exact role unclear, may relate to antioxidant function Signup and view all the answers

At what pool size do scurvy symptoms occur in the body?

300 mg Signup and view all the answers

What is the maximum body pool size of vitamin C in non-smokers per kg of body weight?

22 mg/kg Signup and view all the answers

What happens to the excess of water-soluble compounds like vitamin C?

It is excreted via urine Signup and view all the answers

What is the fate of large intake of water-soluble compounds like vitamin C in the body?

They are degraded in the intestine Signup and view all the answers

What is the similarity between the bioavailability of vitamin C from food and pharmaceutical forms?

It is the same Signup and view all the answers

What is a symptom of scurvy caused by vitamin C deficiency?

Inflamed, bleeding gums Signup and view all the answers

In which countries is scurvy rare, unless there is low fruit and vegetable consumption?

Developed countries Signup and view all the answers

Which species can synthesize vitamin C, unlike humans?

Most species Signup and view all the answers

What is the Recommended Dietary Allowance (RDA) of vitamin C for women 19 years and older?

75 mg Signup and view all the answers

What is the potential consequence of suddenly stopping a high dose of vitamin C intake?

Development of scurvy Signup and view all the answers

What is the Tolerable Upper Intake Level (UL) for vitamin C in adults aged 19 and older?

2000 mg/day Signup and view all the answers

Which form of vitamin E is mostly found in humans?

Alpha-tocophorol Signup and view all the answers

What is the primary concern regarding vitamin E's function in some in vivo conditions?

Pro-oxidative function Signup and view all the answers

What is the potential impact of vitamin E in protecting LDL from oxidation?

Decrease oxidative damage to LDL Signup and view all the answers

What is the primary route of vitamin E excretion?

Through feces Signup and view all the answers

What is the primary symptom of vitamin E deficiency?

Peripheral neuropathy Signup and view all the answers

What is the primary source of vitamin E in food?

Vegetable oils & spreads Signup and view all the answers

What is the primary concern regarding vitamin E toxicity?

Hemorrhagic stroke at high doses Signup and view all the answers

What is the Recommended Dietary Allowance (RDA) of vitamin E for men aged 19-50 years?

15 mg/day alpha-tocopherol Signup and view all the answers

How is vitamin E bioavailability affected by pharmaceutical forms?

Reduced due to lack of fats required for chylomicron formation Signup and view all the answers

What is the primary fate of vitamin E in the body if there is low intestinal absorption?

Excreted through feces Signup and view all the answers

What is the Tolerable Upper Intake Level (UL) for vitamin E in adults aged 19 and older?

1000 mg/day of any form of supplementary alpha-tocopherol Signup and view all the answers

What is the biologically active form of selenium found in animal tissues?

Selenocysteine Signup and view all the answers

Which food source is NOT listed as a good source of selenium in the text?

Leafy greens Signup and view all the answers

How does food content of selenium vary depending on its source?

Depends on the soil content where the plant or animal was raised Signup and view all the answers

What is the UL (Tolerable Upper Intake Level) of selenium for both males and females?

400 mcg/day Signup and view all the answers

Which symptom is linked to selenium deficiency?

Muscular discomfort and weakness Signup and view all the answers

What is the AI (Adequate Intake) of selenium for infants?

15 mcg/day Signup and view all the answers

What is the primary route of selenium excretion from the body?

Urine Signup and view all the answers

What is the Recommended Dietary Allowance (RDA) of selenium for men aged 19-50 years?

55 mcg/day Signup and view all the answers

What is the primary function of Vitamin A in relation to men's health?

Supports sperm production Signup and view all the answers

How is preformed Vitamin A absorbed in the small intestine?

It is hydrolyzed to retinol Signup and view all the answers

What is the efficiency of absorption for preformed Vitamin A?

70-90% Signup and view all the answers

What is the retinol activity equivalency (RAE) ratio for beta-carotene from food?

12:1 Signup and view all the answers

How can one calculate the amount of retinol that can be produced from dietary beta-carotene?

Divide mcg dietary beta-carotene by 12 Signup and view all the answers

Where is retinol stored in the body?

Liver Signup and view all the answers

Which of the following foods is a good source of preformed Vitamin A?

Liver Signup and view all the answers

What is the assumed conversion site of carotenoids to retinol in the body?

Intestines Signup and view all the answers

Which factor is known to reduce the absorption of Vitamin A?

Intestinal infections Signup and view all the answers

What is required for protein synthesis and is essential for Vitamin A absorption?

Zinc Signup and view all the answers

Which substance competes with retinol for enzyme pathways in the body?

Ethanol Signup and view all the answers

What are the symptoms of vitamin A toxicity?

Nausea, vomiting, headache, vertigo Signup and view all the answers

Why is vitamin A toxicity from food unlikely in developed countries?

The body regulates the absorption of vitamin A from food Signup and view all the answers

How does excess vitamin A from supplements cause cell damage?

It saturates protein carriers leading to free vitamin A which causes cell damage Signup and view all the answers

What are the symptoms of Vitamin A toxicity?

Nausea, vomiting, headache, and blurred vision Signup and view all the answers

What is the Recommended Dietary Allowance (RDA) of Vitamin A for men?

900 μg/day Signup and view all the answers

What is the average Vitamin A intake for women aged 18 to 74 years?

1169 RAE (mcg)/day Signup and view all the answers

What is the primary form of vitamin K found in fish oils and meats?

Menaquinone Signup and view all the answers

Which food source contributes significant amounts of vitamin K?

Spinach Signup and view all the answers

What is the primary function of vitamin K?

Blood clotting Signup and view all the answers

Where is Phylloquinone absorbed in the body?

Jejunum & ileum Signup and view all the answers

What is the AI for women for vitamin K?

90 mcg/day Signup and view all the answers

What is the primary cause of secondary vitamin K deficiency symptoms?

Impaired fat absorption Signup and view all the answers

What inhibits vitamin K absorption?

Antibiotics Signup and view all the answers

Why are newborns given a vitamin K injection at birth?

To last until gut microflora are developed Signup and view all the answers

Where does vitamin K toxicity primarily occur?

From excessive supplementation Signup and view all the answers

What is the primary symptom of vitamin K deficiency?

Bruising and hemorrhage Signup and view all the answers

What is the Adequate Intake (AI) of vitamin K for women?

90 mcg/day Signup and view all the answers

What is the primary cause of secondary vitamin K deficiency symptoms?

Impaired fat absorption Signup and view all the answers

What is the primary symptom of vitamin K deficiency?

Bruising and hemorrhage Signup and view all the answers

What is the source of observed vitamin K toxicity in infants?

Excessive supplementation Signup and view all the answers

What is the observed association of low vitamin K with chronic disease?

Osteoporosis Signup and view all the answers

Why are newborns given a vitamin K injection at birth?

To prevent blood clotting inhibition Signup and view all the answers

What is the approximate absorption rate of non-heme iron on average?

10% Signup and view all the answers

Which type of iron is only found in flesh foods such as meat, poultry, and fish?

Heme iron Signup and view all the answers

What is the primary factor that increases the absorption of non-heme iron?

Consumption of iron chelates like ascorbic acid Signup and view all the answers

Where is the majority of body iron found?

In hemoglobin Signup and view all the answers

What is the approximate absorption rate of heme iron on average?

10% Signup and view all the answers

Which food source contains the most iron per gram of content?

Legumes Signup and view all the answers

What is the primary form of iron in the cytochromes of oxidative phosphorylation?

Heme iron Signup and view all the answers

Which factor influences the iron content in food?

Food processing methods Signup and view all the answers

What is the primary plasma protein carrier for iron?

Transferrin Signup and view all the answers

What is the most common cause of anemia?

Iron deficiency Signup and view all the answers

What is the primary form of iron absorption inhibited by calcium and phosphorus?

Heme iron Signup and view all the answers

What is the primary symptom of iron deficiency?

Blue sclera Signup and view all the answers

What is the primary route of iron loss from the body?

Feces Signup and view all the answers

What is the primary factor contributing to increased non-heme iron absorption?

Ascorbic acid Signup and view all the answers

What is the primary contributor to iron stores in the body?

Dietary intake Signup and view all the answers

What is the primary cause of increased iron absorption in individuals with low iron stores?

Enhanced absorption efficiency Signup and view all the answers

What is the primary symptom of iron toxicity in children?

Lethargy Signup and view all the answers

What is the Recommended Dietary Allowance (RDA) of iron for premenopausal women?

18 mg/day Signup and view all the answers

What is the primary route of iron loss from the body?

Menstruation Signup and view all the answers

What is the primary form of iron absorption inhibited by calcium and phosphorus?

Non-heme iron Signup and view all the answers

What is the primary contributor to iron stores in the body?

Iron recycling from red blood cells Signup and view all the answers

What is the primary symptom of iron deficiency?

Impaired intellectual performance Signup and view all the answers

What is the Recommended Dietary Allowance (RDA) of iron for premenopausal women?

18 mg/day Signup and view all the answers

What is the primary effect of radical species on cell proteins?

Promotion of oxidation Signup and view all the answers