Questions and Answers
What are the four fat-soluble vitamins, and what are some good dietary sources for each?
The four fat-soluble vitamins are vitamins A, D, E, and K. Good dietary sources of vitamin A include sweet potatoes, carrots, and dark leafy greens. Vitamin D can be found in fatty fish, fortified dairy products, and sunlight exposure. Vitamin E is abundant in nuts and seeds, such as almonds and sunflower seeds. Vitamin K is found in leafy greens, such as spinach and kale.
What are the major functions of vitamin A in the body, and what health problems are associated with its deficiency?
Vitamin A is essential for vision, immune function, and gene transcription. A deficiency in vitamin A can lead to night blindness, impaired immune function, and skin problems.
What is the primary function of vitamin K in the body, and how does it interact with calcium?
Vitamin K is necessary for blood clotting and bone health. It helps to activate proteins that bind to calcium, which is essential for bone mineralization.
What are the consequences of excessive intake of fat-soluble vitamins, and how do they differ from water-soluble vitamins?
Signup and view all the answers
How do the recommended dietary allowances (RDAs) for fat-soluble vitamins vary across different age groups and populations?
Signup and view all the answers
What is the function of vitamin A in the production, maturation, and maintenance of epithelial cells?
Signup and view all the answers
What is the consequence of vitamin A deficiency on mucus-secreting epithelial cells?
Signup and view all the answers
What is the adult RDA for vitamin A, and what is the unit of measurement?
Signup and view all the answers
What is the role of vitamin A in the immune system?
Signup and view all the answers
What are the major dietary sources of vitamin D?
Signup and view all the answers
What is the adult Upper Level (UL) for vitamin E?
Signup and view all the answers
What is the function of vitamin K in the body?
Signup and view all the answers
What role does vitamin A play in bone growth and development?
Signup and view all the answers
What is the consequence of vitamin E deficiency on the immune system?
Signup and view all the answers
What is the function of rods in the retina?
Signup and view all the answers
What are the major signs and symptoms of vitamin D deficiency in children and adults?
Signup and view all the answers
What is the result of the visual process shown in Figure 8.8?
Signup and view all the answers
What is night blindness, and what causes it?
Signup and view all the answers
What is the importance of vitamin A in reproductive health?
Signup and view all the answers
What is the benefit of consuming dark green leaves of lettuce, cabbage, or broccoli?
Signup and view all the answers
What are some animal foods that are good sources of preformed vitamin A?
Signup and view all the answers
How much retinol does the body obtain from beta-carotene in a food?
Signup and view all the answers
What is the function of cones in the retina?
Signup and view all the answers
What is the role of vitamin A in the immune system?
Signup and view all the answers
What are some plant-based foods that are rich sources of beta-carotene?
Signup and view all the answers
What happens to plant cells when they are exposed to heat?
Signup and view all the answers
What is the purpose of lutein and zeaxanthin in the human body?
Signup and view all the answers
Why do darkly pigmented fruits and vegetables contain more beta-carotene and other provitamin A carotenoids?
Signup and view all the answers
Who is at risk for vitamin A deficiency?
Signup and view all the answers
What happens to epithelial cells in a person suffering from chronic vitamin A deficiency?
Signup and view all the answers
What is the consequence of untreated xerophthalmia?
Signup and view all the answers
Why is vitamin A deficiency a significant public health concern in developing nations?
Signup and view all the answers
What is the recommended dietary allowance (RDA) for vitamin A?
Signup and view all the answers
What is the source of data for Table 8.3?
Signup and view all the answers
What is the purpose of fortifying commonly eaten foods with vitamin A?
Signup and view all the answers
What is the risk of taking vitamin A supplements during pregnancy without consulting a physician?
Signup and view all the answers
What is the recommended daily intake of vitamin A for adults to prevent toxicity?
Signup and view all the answers
What is the purpose of Golden Rice, and what nutrient does it contain?
Signup and view all the answers
What is carotenodermia, and what is its cause?
Signup and view all the answers
Why should women of childbearing age avoid pregnancy while using medications derived from vitamin A?
Signup and view all the answers
What is the historical significance of cod liver oil in relation to vitamin D?
Signup and view all the answers
What is the primary symptom of rickets, and how does it affect the bones?
Signup and view all the answers
What is the classification of vitamin D, and why is it considered a hormone?
Signup and view all the answers
How does vitamin A toxicity affect the liver, and what are the resulting symptoms?
Signup and view all the answers
Why are women of childbearing age advised to limit their intake of vitamin A-rich foods, such as liver and fish liver oils?
Signup and view all the answers
What is the main drawback of using sunscreen to protect against skin cancer, in terms of vitamin D synthesis?
Signup and view all the answers
Why do breastfed infants with dark skin and minimal sunlight exposure need vitamin D supplements?
Signup and view all the answers
What are the characteristic symptoms of osteomalacia, the adult form of rickets?
Signup and view all the answers
How does aging affect the production of vitamin D3 in skin?
Signup and view all the answers
What type of skin cancer is often linked to UV radiation exposure?
Signup and view all the answers
Why are adults who are confined indoors or almost fully covered during the day at risk of osteomalacia?
Signup and view all the answers
How much vitamin D do breastfed infants need to consume daily to prevent rickets?
Signup and view all the answers
Why is vitamin D a 'nutrient of public health concern' in the United States?
Signup and view all the answers
What is the recommended daily intake of vitamin D for adults under 70 years of age?
Signup and view all the answers
What is the benefit of exposing skin to sunlight for about 15 minutes before applying sunscreen?
Signup and view all the answers
Why did Amanda's doctor prescribe her a daily supplement of vitamin D?
Signup and view all the answers
What is the primary source of vitamin D for people who live north of the 33rd parallel during the winter months?
Signup and view all the answers
Why is it important to check the ingredient lists and Nutrition Facts panels of food products for vitamin D?
Signup and view all the answers
What is the potential consequence of not taking vitamin D supplements if you have a deficiency, like Amanda?
Signup and view all the answers
Why is it not recommended to take vitamin D supplements unless you have a deficiency?
Signup and view all the answers
What is the reason Amanda 'crisps' when she gets exposed to the sun?
Signup and view all the answers
What is the role of UV radiation in vitamin D synthesis?
Signup and view all the answers
Why do people living north of the 33rd parallel need to take vitamin D supplements during the winter?
Signup and view all the answers
What is the effect of clouds, shade, window glass, and air pollution on vitamin D synthesis?
Signup and view all the answers
Why was cod liver oil traditionally given to children to prevent rickets?
Signup and view all the answers
What is the effect of taking vitamin D supplements that provide more than 400 IU per day on the risk of hip fracture?
Signup and view all the answers
How does vitamin D deficiency contribute to osteoporosis?
Signup and view all the answers
What is the consequence of excess vitamin D consumption?
Signup and view all the answers
What is the role of vitamin E in the body?
Signup and view all the answers
What are some dietary sources of vitamin E?
Signup and view all the answers
Why is it important to store vegetable oils properly?
Signup and view all the answers
What is the consequence of vitamin D toxicity on the body?
Signup and view all the answers
Why is it important to consume vitamin E-rich foods?
Signup and view all the answers
What is the effect of vitamin D deficiency on older adults?
Signup and view all the answers
Why is vitamin E an important antioxidant?
Signup and view all the answers
What factors influence the amount of vitamin E retained in food?
Signup and view all the answers
Why may premature infants have low vitamin E stores?
Signup and view all the answers
What is the primary function of vitamin K in the body?
Signup and view all the answers
What is the UL for vitamin E in healthy adults?
Signup and view all the answers
Why may taking vitamin E supplements interfere with blood clotting?
Signup and view all the answers
What is the effect of vitamin E deficiency on the nervous and immune systems?
Signup and view all the answers
Why is vitamin K necessary for blood clotting?
Signup and view all the answers
What is phylloquinone, and where is it found?
Signup and view all the answers
What is the effect of vitamin E deficiency on premature infants?
Signup and view all the answers
Why is fat necessary for the absorption of vitamin K?
Signup and view all the answers
What is the role of vitamin K in bone mineralization and which protein is involved in this process?
Signup and view all the answers
Why do people who take warfarin need to maintain consistent dietary intakes of vitamin K?
Signup and view all the answers
What is the consequence of vitamin K deficiency in infants, and how is it prevented?
Signup and view all the answers
What are some reliable food sources of vitamin K?
Signup and view all the answers
What is the Adequate Intake (AI) for vitamin K in adult men and women?
Signup and view all the answers
What are some conditions that can contribute to a deficiency of vitamin K?
Signup and view all the answers
What is the most reliable sign of vitamin K deficiency?
Signup and view all the answers
What is the importance of vitamin K in blood clotting?
Signup and view all the answers
What is the chemical structure of vitamin K like, and how does it respond to cooking?
Signup and view all the answers
What is the consequence of excessive intake of vitamin K?
Signup and view all the answers
What was the mistake that Douglas Mawson and Xavier Mertz made during their expedition that led to severe illness and death?
Signup and view all the answers
What is the primary source of vitamin D for the body?
Signup and view all the answers
What is the role of the kidneys in the production of active vitamin D?
Signup and view all the answers
What is the percentage of calcium absorption in the small intestine when the body lacks vitamin D?
Signup and view all the answers
What is the effect of vitamin D deficiency on bone health?
Signup and view all the answers
What is another role of vitamin D in the body besides bone health?
Signup and view all the answers
Why did Amanda Croker's family doctor prescribe her vitamin D supplements?
Signup and view all the answers
What is the relationship between sunlight exposure and vitamin D production in the body?
Signup and view all the answers
What is the consequence of severe vitamin D deficiency in the body?
Signup and view all the answers
Why is vitamin D often called the 'sunshine vitamin'?
Signup and view all the answers
Study Notes
Fat-Soluble Vitamins
- There are four fat-soluble vitamins: vitamins A, D, E, and K
- These vitamins are essential for various bodily functions and can be obtained from dietary sources or supplements
Vitamin A
- Vitamin A is a family of compounds that includes retinol, a key form of the vitamin in the body
- Functions of vitamin A:
- Involved in vision, particularly in dim light
- Necessary for epithelial cell development, growth, and maintenance
- Important for immune system function and fertility
- Plays a role in bone growth and development
- Food sources of vitamin A:
- Preformed vitamin A: liver, milk, fortified cereals
- Provitamin A (beta-carotene): yellow, orange, and dark green fruits and vegetables
- Deficiency symptoms:
- Night blindness
- Dry skin
- Poor growth
- Reduced immune system function
- Xerophthalmia (dry eye)
- Toxicity symptoms:
- Nausea and vomiting
- Headaches
- Bone pain and fractures
- Hair loss
- Liver damage
Vitamin D
- Vitamin D is actually a hormone that can be synthesized in the skin upon exposure to sunlight
- Functions of vitamin D:
- Necessary for calcium and phosphorus metabolism
- Essential for bone health and development
- Involved in immune system function and regulation of cell growth
- Food sources of vitamin D:
- Fatty fish, fish liver oils, and fortified dairy products
- Deficiency symptoms:
- Rickets in children
- Osteomalacia in adults
- Soft bones
- Depressed growth
- Reduced immune system function
- Toxicity symptoms:
- Poor growth
- Calcium deposits in soft tissues### Vitamin D
- Vitamin D is also known as the "sunshine vitamin" because the body synthesizes it when skin is exposed to sunlight.
- Limited sun exposure can lead to vitamin D deficiency, which can cause soft and weak bones (osteomalacia) and increase the risk of skin cancer.
- Vitamin D is essential for bone health, as it helps the body absorb calcium.
- Dark-skinned individuals, older adults, and people who live in areas with limited sunlight are at a higher risk of vitamin D deficiency.
- The RDA for vitamin D is 15 mcg/day for adults under 70 years old, and 20 mcg/day for adults over 70 years old.
- Food sources of vitamin D include fatty fish, fortified milk, and cereals.
- Vitamin D supplements can be toxic in high doses, and can cause calcium deposits in soft tissues, leading to cellular death.
Sunlight Exposure and Vitamin D
- Sunlight exposure is necessary for vitamin D synthesis, but excessive exposure increases the risk of skin cancer.
- The amount of time needed to spend in the sun to form adequate amounts of vitamin D depends on location, time of day, and skin color.
- People living north of the 33rd parallel may not get enough vitamin D from sunlight during the winter months.
- Clouds, shade, window glass, and air pollution can reduce UV radiation and limit vitamin D production.
Vitamin D Deficiency and Osteomalacia
- Vitamin D deficiency can cause osteomalacia, a condition characterized by soft and weak bones.
- Breastfed infants, especially those with dark skin, are at a higher risk of vitamin D deficiency and osteomalacia.
- Adults who are confined indoors, have kidney or liver disease, or have intestinal disorders are also at risk of osteomalacia.
- Vitamin D supplements can help prevent osteomalacia in high-risk individuals.
Vitamin E
- Vitamin E is an antioxidant that protects cell membranes from damage caused by free radicals.
- Food sources of vitamin E include sunflower seeds, almonds, plant oils, fish, whole grains, and nuts.
- Vitamin E deficiency is rare, but can occur in people with diseases that interfere with fat absorption.
- Vitamin E deficiency can cause nerve damage, loss of neuromuscular control, and blindness.
Vitamin K
- Vitamin K is necessary for blood clotting and bone health.
- Food sources of vitamin K include green leafy vegetables, broccoli, and soybean oil.
- Vitamin K deficiency is rare, but can occur in people with liver disease, conditions that impair fat absorption, and those taking long-term antibiotics.
- Newborns are generally given a vitamin K injection to prevent deficiency.
- Vitamin K deficiency can cause bleeding disorders and increased risk of osteoporosis.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Description
Explore the importance of fat-soluble vitamins, specifically vitamin A, and their roles in vision, epithelial cell development, and immune system function.