4.1 Vitamine: Vital Dietary Components: ●
Vitamins
○ Organic compounds that the body needs in small amounts
○ In diet, help regulate + support processes related to digestion, abd, metabolism,
body regulations
○ No energy but important for growth and maintenance ●
Essential vitamins
○ 13, found in plant/animal sources and can not be synthesizaed by the human body
so we must consume
○ Vitamin K, biotin
● Precursors
○ Substances in food/body that have to be converted to the active form before they
can function as a vitamin
○ Ex: vitamin A can be produced from precursor beta carotene ●
To be a vitamin an organic compound must
○ Due to inability of our body to manufacture the compound, enough of the
compound must be consumed in the diet to maintain health
○ Symptoms of deficiency occur in the absence of the compound. Health is
restored when we fix deficiency. ● Manufacturing
○ During manufacturing some nutrients are lost so some foods have been enriched
or fortified to ensure we get the nutrients we need. ● Enrichment
○ Process of taking nutrients lost in milling/processing and adding them back to final
pdt
○ Grain pdts ●
Fortification
○ Supplemenenting a product w additional vitamins rhat would not be in there to
begin with
○ Adding calcium to orange juice ●
Fat soluble vitamins
○ Dependent on dietary fat for absorption, once absorbed these vitamins are stored
in liver and adipose tissue
○ ADEK, not easily excreted from storage, eating too many can lead to toxic levels in
body
○ A and D have highest likelihood to become toxic
○ Some disease, weight loss meds interfere w fat abs and lead to deficienty ●
Vitamin A
○ 2 forms
■ Preformed vitamin A retinol
● From animal sources ■ Provitamin A
carotenoids
● Plants, pigments that can later be converted into
vitamin A
, ● Found in yellow, orange, red veggies,
sometimes considered antioxidant
○ Many functions but most profound is effect on vision
○ Retinal is form of vitamin a that helps the eye adjust from bright to dim light
■ If not enough, this is called night blindness and indicator of deficiency, if
continues eye loses ability to make mucus and keep it moist
■ Abnormal dryness due to vit a deficicny is called xeropthlamia
● Blindness if untreated
○ Eating many fruits/veggies with lots of carotonoids may treat to macular
degeneration (cause of vision loss)
○ Also important for skin health and epithelial cells of GI tract. ○
Also needed for growth, development, reproduction
■ Lack of vitamin A stuns growth in kids and cant reproduce as adults
○ Also helpful in disease prevention
■ cancer/cardiovascular disease can help be prevented w vitamin A
especially carotenoius
○ Studies show its better to consume vitamin A in pill then food
○ In liver, fish, fish oils, yogurt
○ Provitamin A carotenoids in dark leafy veggies, yellow/ orange fruits/veggie
■ No limit on this but too much can cause yellowing of hands/sole of feet if
lots yellow/orange veggies (carotenodermia)
○ Limit of vitamin A is 3000 micrograms a day levels above this would be toxic
○
● Antioxidant
○ Stop reactive substances from causing damage to cells
○ Protect cells from damage by free radicals formed during chemical reactions
■ Carotenoids including lycopene, zexanthin, lutein ●
Vitamin D
○ Vitamin and a hormone ○
Occurs in 2 forms
■ Ergocalciferol (D2): synthetic product used in supplements
■ Cholecalciferol (D3): made by human body
○ 10 minutes of sun 2 or 3 times a week provides 80-100% of vitamin D
○ If no sun then dietary intake is very important
○ In fatty fish, fortified cereal, eggs
○ Main function is to regulate calcium levels andbone metabolis
○ With PTH, vitamin D regulates calcium and phosphorus from the intestine and
deposition of calcium in bone
○ Vitamin D also important for immune, skin development, muscle health, bp control
○ In adults, inadequate ca abs and deposition causes osteomalacia which means
soft bones