Exam 3 Flashcards
(148 cards)
What are the factors that affect the bioavailability of vitamins and minerals?
- Efficiency of digestion (ex; diarrhea, bariatric surgery, gallbladder disease, pancreatitis)
- Previous nutrient intake and nutritional status
- Other foods eaten at the same time
- Food processing and preparation techniques
- Source of vitamin (natural food source, synthetic source, fortified)
Are water-soluble or fat-soluble vitamins needed on a daily basis?
Water-soluble vitamins are needed on a daily basis while fat-soluble vitamins are not.
What is required for the absorption of fat-soluble vitamins?
Requires fat and bile for absorption.
What is golden rice, and how is it related to vitamins?
Golden rice is white rice that has been fortified with vitamin A. It is a genetically modified food.
How is Vitamin D from the diet activated?
Vitamin D, calciferol, from the diet is absorbed in GIT and moves through the bloodstream on its way to lymph nodes. After that, it heads to the liver, where it is converted to 25-(OH) D3/ calcidiol. This then travels to the kidneys, where 1 alpha-hydroxylase converts it to 1,25-(OH)2 D3/ Calcitriol.
How is Vitamin D from the sun activated?
Vitamin D can be made when skin cells are exposed to UV radiation because a cholesterol derivative, 7-dehydrocholesterol, is activated into cholecalciferol. This is now vitamin D3 that follows the same liver and kidney process as dietary intake situation.
What is the most active form of vitamin D?
1,25 di OH vit D/ Calcitriol is 10 times as active as cholecalciferol.
What is the most readily absorbed form of vitamin D?
Cholecalciferol
What are the best dietary sources for vitamin D?
Fish, fish oils, fortified products like milk, cereal, orange juice, and margarine
What are the primary functions of vitamin D?
Important for the metabolism of calcium and phosphorus. Calcitriol promotes the absorption of calcium through the stimulation of calcium-binding protein. CRITICAL FOR BONE HEALTH! Vitamin D also regulates neuromuscular and immune function and reduces inflammation.
What hormone is released when blood calcium levels fall?
Parathyroid hormone (PTH) is secreted from parathyroid glands. This will stimulate vitamin D activity, increase osteoclast activity (bone breakdown), increases calcium retention in kidneys and increases absorption in the small intestine.
What is the hormone secreted when blood calcium levels rise?
Calcitonin is secreted from the thyroid glands. This inhibits vitamin D activity, increases osteoblast activity (bone building), decreases calcium retention in the kidneys and decreases calcium absorption in the small intestine.
What is the RDA for vitamin D?
Males and females 18-70 years: 15 micrograms
Males and females older than 70: 20 micrograms
What is the UL of vitamin D?
100 micro grams
What does the deficiency of vitamin D cause in children?
Vitamin D deficiency causes rickets in children. This includes bowed legs, knocked knees, and pigeon chest.
It causes osteomalacia in older adults, which includes symptoms like softening of bone, bending of spine, and bow legs.
What does the deficiency of vitamin D cause in adults?
Osteomalacia. This is the softening of the bones, bending of spine, and bowed legs.
Is breastmilk a good source of vitamin D?
NO! Supplementation is needed.
How many forms of vitamin E are there, and what are they called?
There are 8 forms. 4 of them are called tocopherols, and the other 4 are called tocotrienols. Only alpha-tocopherol is maintained in the plasma and used in the body.
What is the biological activity of alpha-tocopherol?
Alpha-tocopherol has a biological activity of 1.
What form of vitamin E is found in most foods and supplements?
Alpha-tocopherol
How biologically active is gamma-tocopherol (found in some foods and supplements)?
0.1-0.3 biological activity
What are the best dietary sources of vitamin E?
Sunflower seeds, almonds, vegetable oil, wheat germ, and peanuts
Vitamin E is NOT lost during the milling process and can be restored by enrichment if lost (T/F).
FALSE! Vitamin E is lost during milling and cannot be restored via enrichment
What are the main functions of vitamin E?
ANTIOXIDANT! Vitamin E can help protect against atherosclerosis, cancer, premature cell ageing and death.