May 14: Fat Soluble Vitamins Flashcards
Vitamin D function
Calcium metabolism:
Calcium absorption
Regulation of blood calcium levels (kidneys)
Bone mineralization by maintaining calcium concentrations
What are some possible additional functions of vitamin D?
Possibly cancer prevention?
(Low circulating vitamin D linked to increased cancer risk)
Protection against cardiovascular disease and hypertension
Prevention of autoimmune diseases
Where is vitamin D deficiency a problem?
It is a problem in areas with reduced exposure to sunlight
What can vitamin D deficiency cause?
Rickets in children
Overgrowth of cartilage
Enlarged head
Rickets
Soft bones
How can vitamin D need be met?
Through 30 minutes to 2 hours of daily sunlight exposure
RDA for vitamin D
600 IU (international units) for ages 1-70
800 IU for 70+ age
Food sources of vitamin D
Fatty fish, fortified milk, mushrooms (grown under UV light)
Vitamin D toxicity
2-3 times the RDA is toxic to children
Vitamin A function
Vision cycle - ability to perceive black/gray/white/night vision
Maintenance of epithelial tissue (“covering tissue”)
Vitamin A deficiency
Can cause night blindness, xerophthalmia, infection
Xerophthalmia
Cornea sloughs off, causing blindness
500,000 children < 5 years old go blind yearly due to vitamin A deficiency
Food sources of vitamin A
Animal sources, beta carotene (any green, orange, or red fruit/veg. This is converted to vitamin A)
What if you eat too much beta carotene or vitamin A?
Beta carotene isn’t toxic so this isn’t a problem; it acts as an antioxidant
However, vitamin A can be toxic. It is stored in the liver and excess can lead to birth defects, enlarged liver
Vitamin E function
Antioxidant: protects cell membranes from oxidation
Prevents lipid “peroxidation”
Vitamin E deficiency
Hemolytic anemia: red blood cells break
Takes about 7 years to become deficient
RDA for vitamin E
Male/female: 15 mg (22 IU)
Tolerable upper limit: 1000 mg
Food sources for vitamin E
Vegetable oils, nuts, seeds, whole grains
Which nutrients function as antioxidants in the body?
Vitamin E, Vitamin C, beta carotene
Why might one need a vitamin/mineral supplement?
If calorie intake is <1,500 kcal/day (female, older age)
If alcohol is heavily consumed
If pregnant (iron)
If they have irregular eating habits and limited selection of food
Dietary Supplement Health and Education Act 1994
Label statements may describe effects of ingredients on body as “structure” or “function” but can’t state a “drug-like” effect or “disease cure”
For accurate supplement info
Look for sites operated by the government, health organizations, or universities
Check the Office of Dietary Supplements website
