Unit 5 Flashcards
structure of vitamins and minerals
vitamins or organic individual units
minerals are inorganic individual units
Function
both do not yield energy, but can assist enzymes to release energy
- vitamins can be broken down, minerals can’t
Food contents
vitamins: micrograms (ug) to milligrams
minerals: micrograms to grams
bioavailability
includes the amount in food, amount absorbed & used by body
Factors:
- efficiency of digestion, time of travel
- nutrient status
- food preparation method
- source of nutrient
- other foods present
precursors
- available for foods in a inactive form
- precursors of provitamin
- converted to the active form in the body
- ex. Vit A,D
solubility
water-soluble: B vitamins, vit C
fat soluble: vit A,D,E,and K
vitamins destroyed
heat, UV and florescent light, oxygen
- veggies in fridge and closed container
- cook veggies for as little time with as little water as possible to keep nutrients
toxicity
more doesnt equal better
- tolerable upper intake levels
- not all have an UL, does not mean they are not harmful if consumed in excess
Nutrient interactions
- presence or absence can influence absorption, metabolism and excretion
1. folate naturally occurs as polyglumate
2. in intestine, digestion breaks down glutamates off and adds methyl group. folate is absorbed and brought to cells
3. in cells, folate is trapped in its inactive form
4. to activate folate, vit B12 removed and keep methyl groups which activated B12
5. both folate coenzyme and the vit B12 coenzyme are now active and availible for RNA synthesis
Nutrients for energy metabolism
- B vitamins
- thiamin
- riboflavin
- niacin
- biotin
- plantothenic acid
- vit B6
- folate
- Vit B12
B vitamins act as coenzymes
- vits and minerals aid enzymes in releasing energy from macronutrients
- b vitamins form part of coenzymes
food sources for B vits
veggies and fruits - folate grain products - thiamin - riboflavin - niacin - folate Milk and Alt. - riboflavinn - B12 Meat and alt - thiamin - niacin - vit B6 and B12
Minerals for energy metabolism
sulphur
iodine
manganese
chromium
the B vitamins
- individually and collectively play a major role in metabolism
- work together and often mask each others deficiency
- water-soluble
- do not contain energy, but w/o them - no energy
- various minerals also contribute to human metabolism
Antioxidant nutrients: overview
- protect cells from oxidative damage
- vitamins quench free radicals
- minerals act as cofactors for enzymes
- oxidation is part of normal metabolism
- unpaired electrons = free radical
- antioxidants neutralize free radicals
Antioxidant vitamins
A, E & C
Vitamin A and Beta-carotene
can overconsume vit A, which is toxic
cannot overconsume beta-carotene, but it can turn your skin orange
- 3 diff forms for vit a
conversion to retinoic acid is permanent
Sources of Vit A and beta-carotene
animal sources are riches - liver, fish, oil. dairy products, eggs Plant - dark leafy greens - yellow or deep orange veggies/fruits
Vit E as an antioxidant
fat soluble
- tocopherals
- primary defende against free radicals
- prevents the from producing more free radicals
- cell membranes and other lipids
reduces risk of cardiovascular disease
4 diff forms: alpha,beta,gamma,delta
primary function: prevent damage of lipids and cell membranes and prevent oxidation of LDL