Chapter 8 Flashcards
What is a vitamin?
an organic compound essential in small quantities for normal metabolism and must be obtained from the diet because the body cannot synthesize enough of it.
What is a coenzyme?
A non-protein compound necessary for the functioning of an enzyme, helping enzymes catalyze reactions.
Water-soluble
(e.g., B-vitamins, Vitamin C) dissolve in water and are excreted in urine
Fat-soluble vitamins?
(A, D, E, K) are stored in fat tissue and the liver.
What is enrichment? Give an example.
process of adding back nutrients lost during food processing, like adding B vitamins to refined flour.
What is fortification? Give an example
process of adding nutrients to foods that weren’t originally there, like adding Vitamin D to milk.
What is bioavailability?
the proportion of a nutrient that is absorbed and used by the body.
What are the food sources of thiamin (Vitamin B1)?
Whole grains, enriched cereals and breads, pork, organ meats, legumes, and some green leafy vegetables.
What is the active form of thiamin and its function?
thiamin pyrophosphate (TPP), which is involved in energy production and nerve function.
What are the symptoms of thiamin deficiency?
muscle wasting, nerve damage, cardiovascular problems, and neurological symptoms, leading to beriberi.
What is the significance of polished/white rice in relation to thiamin?
Polished rice has the bran removed, leading to thiamin loss, which historically caused beriberi in populations reliant on white rice.
What is the coenzyme form of riboflavin (Vitamin B2)?
FAD (Flavin adenine dinucleotide) and FMN (Flavin mononucleotide)
What are the functions of riboflavin?
involved in energy production, fatty acid breakdown, and activating other vitamins like niacin, folate, and B6.
What are the symptoms of riboflavin deficiency (ariboflavinosis)?
Inflammation of eyes, lips, mouth, tongue; scaly skin; cracks in the corners of the mouth; confusion.
Why is the clear milk bottle significant for riboflavin?
Riboflavin is sensitive to light and can be destroyed if exposed, so opaque containers are recommended.
What are the forms of niacin (Vitamin B3)?
Nicotinic acid and nicotinamide.
How is niacin synthesized in the body?
from the amino acid tryptophan if dietary tryptophan levels are adequate.
What is the coenzyme form of Vitamin B6?
Pyridoxal phosphate (PLP).
What is the deficiency disease associated with niacin?
Pellagra, characterized by dermatitis, diarrhea, and dementia (the 3 D’s).
What are the functions of Vitamin B6?
Involved in amino acid metabolism, neurotransmitter synthesis, hemoglobin production, and conversion of tryptophan to niacin.
What are the food sources of Vitamin B6?
Meat, fish, poultry, legumes, nuts, enriched cereals, and some fruits and vegetables.
What is folate’s role in the body?
necessary for DNA synthesis, cell production, and the synthesis of amino acids.
What are the symptoms of folate deficiency?
Macrocytic anemia, increased risk of neural tube defects in pregnancy, and increased risk of heart disease and cancer.
What are the sources of folate in the diet?
Green leafy vegetables, oranges, legumes, seeds, organ meats, eggs, and enriched flour.
What is the function of Vitamin B12 (cobalamin)?
It is essential for nerve function, DNA synthesis, and red blood cell formation.
How is Vitamin B12 absorbed?
requires stomach acid and intrinsic factor for absorption in the small intestine.
What are the symptoms of Vitamin B12 deficiency?
Megaloblastic anemia, nerve damage, and neurological symptoms.
What are the functions of Vitamin C?
Collagen synthesis, antioxidant activity, immune function support, and iron absorption.
What is scurvy?
deficiency disease of Vitamin C, leading to poor wound healing, bleeding gums, and joint pain.
What is an antioxidant?
A compound that neutralizes free radicals, preventing cellular damage.
Does Vitamin C prevent colds?
Vitamin C may reduce the duration and severity of colds, but it doesn’t prevent them.
What are the food sources of choline?
Milk, liver, eggs, legumes, and peanuts.
What are high food sources of water-soluble vitamins?
Whole grains, enriched cereals, meats, fish, poultry, leafy greens, legumes, and fresh fruits (especially for Vitamin C).
What populations are at risk for water-soluble vitamin deficiencies?
Vegans, elderly, pregnant women, alcoholics, and individuals with certain medical conditions (e.g., gastrointestinal disorders)
