vitamins from "fat soluble vitamins" lecture Flashcards
Which vitamin is important for vision?
Vitamin A
Vitamin A can be found as ____ or ____
Pre formed or pro vitamin
In Canada, dairy products are fortified with vitamin A. T or F
t
Does vitamin A have toxicity, if so what are the symptoms?
Headache, vomiting, hair loss, liver damage, skin changes, bone and muscle pain, fractures and birth defects
How much of the preformed vitamin A is absorbed?
70-90%, pro vitamin A is less absorbed
How is vitamin A used in the body?
Stored in the liver
Must be transported in the blood by a carrier protein (retinol binding protein)
Acts as an antioxidant
Critical to vision and the conversion of light to signals in the brain
Control of gene transcription and cell differentiation
What is the bioavailability for vitamin A?
Must be released from food by acidity and enzymes
Stable when heated, but destroyed by exposure the light and oxygen
Combines with bile and fats to be absorbed
What are signs of deficiency in vitamin A?
Impaired vision including night blindness Impaired cell differentiation (increased keratin production, impaired immunity and impaired growth and development)
In what countries is a vitamin A deficiency most common?
India, Africa, Latin America and Caribbean (not in developed countries)
When can vitamin A become toxic?
At extreme dosage
What is the function/purpose of vitamin A?
Retinoic Acid (Rein A, Accutane) used to treat acne, wrinkles due to sun damage (increased turnover of cells and can have side effects) Carotenoids (pro vitamin A) are less toxic as our body will stop absorbing them when levels are high Golden rice
What is golden rice?
A strain of rice genetically modified to produce B-carotene
What is the purpose of golden rice?
Has potential to reduce the impact of vitamin A deficiency in low income regions Caught up in the pushback against GMO foods
How is vitamin D produced?
in the skin using radiation from the sun- known as the sunshine vitamin
When exposure to the sun is low, how is vitamin d obtained?
diet
In Canada, foods are fortified with Vitamin D including dairy products. T or F
t
Is there toxicity in vitamin D, if so what are the symptoms?
Calcium deposits in soft tissues, growth retardation and kidney damage
What is the bioavailability for vitamin D?
Major source is exposure to sunlight Animal products contain Cholecalciferol (vitamin D3)
How is vitamin D used in the body?
Made from cholesterol and converted into vitamin D3 in the skin Vitamin D3 is consumed in the diet from animal products Vitamin D3 circulates in the blood but is still inactive Processing in the liver and kidney produces the active form of Vitamin D Vitamin D levels work with parathyroid hormone to control calcium levels in the body
What condition is a manifestation in adults for vitamin d deficiency?
Osteomalacia - results in a greater risk of bone fractures, muscle and bone pain
People on what diet have a greater risk of vitamin D deficiency?
Individuals who follow a vegan or vegetarian dietary pattern appear to be at greater fracture risk
Vitamin D deficiency in children results in what condition?
Rickets, supplementation is recommended
Those living in what environmental conditions receive insufficient UV radiation for vitamin D synthesis?
Those living about 40 degrees latitude N and 40 degrees south
Calcium absorption is inadequate without which vitamin?
vitamin D - therefore bones form poorly
It is estimated that how many people in the world have a vitamin D deficiency?
1 billion
who is vitamin D supplementation recommended for?
Breastfed infants
Those living in northern Canada during the winter
All Canadians over 50
Vitamin D supplements do not appear to reduce fracture risk in adults with no other risk factors for fractures
what is vitamin E identified as?
a fat soluble vitamin required for fertility in lab rats
Anti oxidant
does vitamin E have toxicity, if so what is the result?
NON TOXIC BUT can inhibit vitamin K activity
what is the bioavailability for vitamin E?
Destroyed by oxygen, metals, light and heat
Much is lost during processing
how is vitamin E used in the body?
- converted to chylomicrons, transported throughout the body
- incorporated into VLDL particles for delivery
- Scavenges free radicals before damage, protects proteins and DNA from damage
- regenerated by Vitamin C
what are the signs and symptoms of vitamin E deficiency?
- poor muscle coordination, weakness and impaired vision
Newborns and infants born premature have low vitamin E
Most vitamin E transfer occurs in the last weeks of pregnancy
risk of hemolytic anemia because RBC membranes are less stable
what is vitamin E purpose/function?
promote hair growth
increase sexual potency and fertility
Alleviate fatigue
Maintain immune function
Enhance athletic performance
Reduce the symptoms of PMS and menopause
Slows aging
chickens who were fed a fat free diet developed what disorder?
bleeding disorder
is there toxicity for vitamin k, if so what is the result?
Can interfere with anticoagulant drugs
what is the bioavailability for vitamin K?
destroyed by light and low or high acid conditions
can be produced by bacteria in the human gut
- but not enough for dietary needs
how is vitamin K used in the body?
Vitamin K is necessary to enable blood clots to form
require carboxylase modification of clotting factors to function
required for the formation of fibrin
what are the signs of a vitamin K deficiency?
Abnormal blood coagulation (blood does not clot)
may occur due to fat malabsorption or long term use of antibiotics
Most common in newborns
what is the function/purpose of vitamin K?
Pre op injection to aid in blood clotting
vitamin K ANTAGONISTS are used to prevent blood clots
