Ch. 8 (Edited): Vitamins and Phytochemicals Flashcards
What is a vitamin?
Essential organic (carbon-containing) substances needed in small amounts in the dietary pattern for normal function, growth, and maintenance of the body.
What are the two types of vitamins?
Fat-soluable and water-soluable
What are the fat-soluable vitamins?
Vitamins A, D, E, and K
How are fat-soluable vitamins stored and transported?
They are stored mostly in the liver and fatty tissues. They travel with dietary fats as part of chylomicrons to reach body cells.
How are fat-soluable vitamins absorbed?
They are absorbed in the presence of dietary fat. About 40-90% of these vitamins are absorbed.
How are water-soluable vitamins absorbed?
After being ingested, B vitamins are broken down into free vitamins, absorbed (about 50-90% of them), transported to the liver via the hepatic portal vein, and distributed to body tissues. Once inside cells, they are resynthesized into their coenzyme forms.
Fat-soluable vitamins are not readily excreted from the body. Because of this, what can happen from having too much fat-soluable vitamins?
There may be an issue of toxicity.
How are water-soluable vitamins excreted?
When the tissue vitamin stores are full (tissue saturated), the rate of excretion increases sharply. This prevents toxication. (Except B-6 and B-12)
What are the two types of vitamin A?
Retinoids and carotenoids
Which type of vitamin A has antioxidant effects?
Carotenoids
Where is vitamin A found in the diet?
Preformed vitamin A is often found in protein and animal foods, while carotenoids are mainly found in dark-green and yellow-orange vegetables and some fruits
What are the functions of vitamin A?
They help improve vision, assist with growth/development of the cell structure, and help with the immune system.
How does vitamin A deficiency effect the body?
There is impaired vision, weakened immune function, and stunted growth
How does vitamin A toxicity effect the body?
There is increased risk of birth defects and liver toxicity
Where is vitamin D found in the diet?
Although sunlight is the best source of vitamin D, you can find some in high protein foods, fortified milk, and breakfast cereals
How is vitamin D synthesized?
The sunlight converts 7-dehydrocholesterol in your skin to vitamin D3. The vitamin D3 then enters the bloodstream and goes to the liver and kidney
What function does vitamin D have on the body?
It maintains the normal range of calcium and phosphorus in the blood.
How does latitude effect vitamin D deficiency?
The amount of sunlight one gets can change depending on your latitude. It’s possible for people near the poles to barely get any sunlight, resulting in a vitamin D deficiency.
What are vitamin D deficiency diseases?
Rickets and osteomalacia
What are the functions of vitamin E?
It mainly serves as an antioxidant, but it can also play a role in formation during early human development.
Where is vitamin E found in our food?
Mostly in plant products (especially the oils)
What is the deficiency disease related to vitamin E?
Hemolytic anemia
Where is vitamin K found in the diet?
Mostly vegetables; particularly green leafy vegetables and peas
What is the function of vitamin K in the body?
It synthesizes blood clotting factors and helps with bone health
What are some factors that make foods lose vitamins, and what can be done to limit this?
Factors that influence vitamins are heat, oxygen, light, water and storage time. Using gentle cooking methods like microwaving can help minimize losses.
What is the main role of B-Vitamins?
They help enable the metabolism processes for all macronutrients by interacting with enzymes.
What do coenzymes do?
They interact with enzymes to enable the enzymes to function.
What is the difference between enrichment and fortification?
Enrichment means adding back the original nutrients that were lost during food processing, while fortification means adding vitamins to a food that weren’t originally in the food.
What 4 B-vitamins are required to be enriched in milled grains?
Thiamin, riboflavin, niacin, and folic acid
What function does thiamin (B1) have, and which foods can it be found in?
It helps with metabolism of carbohydrates and branched-chain amino acids; it can be found in small amounts in a wide variety of foods.
What function does riboflavin (B2) have, and which foods can it be found in?
It helps with many metabolic pathways, such as the breakdown of fatty acids and metabolism of vitamins and minerals; mostle foods from the grains, dairy, and protein groups
What function does niacin (B3) have, and which foods can it be found in?
Its coenzymes participate in oxidation-reduction reactions; foods from the protein group
What function does B-6 have, and which foods can it be found in?
Helps with activity of numerous enzymes involved in macronutrient metabolism; mostly animal products and breakfast cereals
What function does pantothenic acid (B5) have, and which foods can it be found in?
Helps create a coenzyme that allows the release of energy from macronutrients; meat, milk, and vegetables
What function does biotin (B7) have, and which foods can it be found in?
Helps cozymes add CO2 to various compounds; found in many foods, especially foods from protein group
What function does folate (B9) have, and which foods can it be found in?
It supplies or accepts single carbon compounds, which helps with DNA synthesis and metabolism of amino acids; green leafy vegetables are great sources of folate
What function does vitamin B12 have, and which foods can it be found in?
Helps folate do its job; animal products are filled with vitamin B12
What is unique about riboflavin exposure to light?
Although it is stable, it can be destroyed via exposure to light.
What function does vitamin C have, and which foods can it be found in?
It functions as an electron donor, which also helps with deoxyfication. (This helps prevent certain cancers!) Can be found in fresh, ripe fruits and vegetables
Which deficiency disease is associated with thiamin?
Beriberi (“I can’t, I can’t) (Weakness, loss of appetite, irritability)
Which deficiency disease is associated with riboflavin?
Ariboflavinosis (Inflammation of mouth, eye disorders, confusion)
Which deficiency disease is associated with niacin?
Pellagra (“Rough or painful skin”) (Dementia, diarrhea, dermatitis)
Which deficiency disease is associated with folate?
Macrocytic anemia (There is fewer mature red blood cells present)
Which deficiency disease is associated with vitamin B-12?
Pernicious anemia (Sore mouth, depression, severe nerve degeneration)
Which deficiency disease is associated with vitamin C?
Scurvy (Bleeding gums, tooth loss, bruising)
What group of people should ensure adequate folate in their diet?
People with limited financial resources or physical problems, and people with an alcohol use disorder
How does folate relate to neural tube defects?
Low maternal plasma folate and vitamin B-12 levels are risk facotrs for neural tube defects.
What are the two types ofneural tube defects?
Spina bifada (spinal cord or spinal fluid bulge through back) and anencephaly (absence of major part of the brain)
