vitamin
essential" nutrients; organic compounds. needed in small amount
water-soluble vitamins
B vitamins, vitamin C
fat-soluble vitamins
vitamins A, D, E, K
where are vitamins found
naturally
another source of vitamins
fortification
voluntary fortification
not mandated by the government
How vitamins get 'released' from food
mechanical digestion (chewing) in the mouth. chemical digestion in the stomach (some) but more in the small intestines (pancreatic digestive enzymes)
vitamin absorption occurs
mainly in the small intestine
micelle
a particle that is formed in the small intestine when the products of fat digestion are surrounded by bile. facilitates the absorption of fats and fat soluble vitamins via simple diffusion
chylomicrons
a lipoprotein comprised of newly reassembled TGs, cholesterol, and fat-soluble vitamins that are packaged with phospholipids and protein.
Bacteria can do what in large intestines
make a small amount of some vitamins, some of which are absorbed
Bioavailibility
extent to which the body can absorb and use a nutrient
Bioavailability is influenced by...
composition of the diet, conditions of the GI tract, and overall health of the body
Diet very low in fat...
impair fat-soluble viatmin absorption
Low concentration of blood proteins...
impair water-soluble vitamin absorption
Provitamin/vitamin precursor
compound in its inactive form that is converted to the active form once in the body
Coenzyme
organic non-protein substance that binds to an enzyme to promote the activity of the enzyme with which it is bound
Active enzyme
enzymes that require coenzymes
Vitamin needs can be met by
meeting calorie needs, consuming nutrient-dense foods, and eating a diet pattern suggested by MyPlate and Dietary Guidelines for Americans
Food labels on packaged foods are currently required to list what vitamins as a % daily value
vitamins A and C
water-soluble vitamins are generally
easily absorbed
are water-soluble vitamins stored in the body to a large extent
no, excess excreted in urine. Therefore, must be consumed regularly
B vitamins
thiamin, riboflavin, niacin, folate, B6, B12, biotin, and pantothenic acid "Tender romance never fails with 6 or 12 beautiful pearls
do B vitamins provide us with energy?
no
Thiamin
B vitamins, part of a coenzyme needed in energy metabolism, aids in breakdown of glucose to provide us with energy.
*
TEST Q
* All OF B VITAMINS ACT AS WHAT
1 OR MORE COENZYMES
Deficiency of thiamin
beriberi, glucose can't be used normally, nerve impulses can't be transmitted normally
Symptoms of beriberi
loss of sensation in the hands and feet, muscle weakness and poor coordination; advancing paralysis, poor short-term memory and confusion, and changes to the heart
Riboflavin is a part of how many coenzymes
2
Main functions of riboflavin
forms two active coenzymes that act as electron carriers functioning in reactions needed too produce ATP from CHO, fat, and proteins
A deficiency of riboflavin...
rarely occurs, and if it does it usually occurs in conjunction with other B vitamin deficiencies
Symptoms of a riboflavin deficiency
cheilosis (cracking and redness of the lips and corners of the mouth), glossitis (inflammation of the tongue, red and swollen) and the eyes have an increased sensitivity to light, burning, tearing and itching of the eyes
Niacin is a part of two coenzymes that are involved in...
metabolism of glucose, fat, and alcohol, and synthesis of fatty acids and cholesterol
Niacin can be made in the body from
tryptophan (essential amino acid)
Niacin-deficiency disease
Pellagra
Pellagra symptoms
start as fatigue, decreased appetite and indigestion. As it progresses symptoms become the 4 'D's --> diarrhea, dermatitis, dementia, death
Those at risk for pellagra
poorly nourished, alcohol addicts
Biotin functions
plays an important role in energy metabolism, needed in synthesis of glucose from non-carb sources, needed in synthesis of fatty acids (a deficiency is rare)
Pantothenic Acid
component of coenzyme A (CoA)
Pantothenic Acid is involved in
the breakdown of CHO, amino acids, fatty acids. Assists with the making of acetyl CoA. Involved in the modification of proteins. Also needed in the synthesis of lips and neurotransmitters.
Vitamin B6
role in amino acid and protein metabolism. needed to convert tryptophan into niacin. needed to break down glycogen. needed for synthesis of hemoglobin and in the conversion of homocysteine to cysteine
folate
needed for the metabolism of some amino acids
Adequate intakes of what before and during early pregnancy can greatly reduce the risk of having a baby being born with a neural tube defect such as spina bifida and anencephaly
folic acid
Vitamin b12
required for the making of new cells. needed for the making of ATP from certain fatty acids, needed for the maintenance of myelin sheath.
Vitamin B12 in food is bound to what
food proteins
*
TEST Q
* Absorption of B12
a protein made in the stomach, needed for B12 to be absorbed, binds to b12 in upper small intestines
Deficiency of B12
pernicious anemia
Pernicious anemia
characterized by large immature RBCs that can cause nerve damage - vegans and older adults are at risk
*
TEST Q
* Vitamin C
(ascorbin acid) MANY FUNCTIONS -
1. Assists enzymes in the synthesis and maintenance of collagen
2. It is an antioxidant, which protects substances from oxidation by free radicals; sacrifices itself by donating electrons.
3. Helps to protect circulating v
Vitamin C deficiency
scurvy
Choline
NOT a vitamin but considered an essential nutrient - water-soluble "substance". needed for synthesis of neurotransmitter, making of cell membranes, involved in transportation of lipids, needed in the metabolism of homocysteine
Choline deficiencies
during pregnancy: interfere with brain development of the fetus
in adults: fatty liver and muscle damage
Vitamin A
fat-soluble. Two forms: retinoids (preformed Vitamin A) and carotenoids (active form of Vitamin A). Beta-carotine = type of carotenoid
Functions of Vitamin A
Role in gene expression (regulates the expression of certain genes, deficiency hinders the making of protein).
Helps to keep the cornea healthy.
Helps with the growth and replenishment of epithelial tissue.
Aids in our ability to smell, hear, and taste.
K
Vitamin D
fat-soluble. Obtained from both food and UV light of the sun
Functions of Vitamin D
Regulation of calcium and phosphorus in the bones and teeth
Vitamin D deficiency
Rickets in children (unable to mineralize newly formed bone, legs become "bowed" because of not being able to support body weight
Osteomalacia in adults (loss of bone minerals, increased risk for fractures)
Vitamin E
an antioxidant, protects the body against oxidative damage, donates electrons to highly reactive free radicals.
Absorption of vitamin E
with fat in the small intestine via micelles
Vitamin K
main function = clotting of blood. needed in two of the 14 steps in the formation of a blood clot
free radical
an atom or molecule that has one or more unpaired electrons. This makes them highly reactive and potentially destructive
At birth, newborns do not possess bacteria to make vitamin K so...
they are given an oral dose of it