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22 Cards in this Set
- Front
- Back
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-fat soluble
-several different forms are found in the body -humans can make it from a cholesterol-like compound and sunlight |
vitamin D
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generally, ______ _____ functions at a genetic level, allowing certain genes to be expressed (by indirectly making proteins that function as enzymes, hormones, etc)
-______ ____ binds to a molecule called ‘____ ___ receptor’ (VDR) -VDR found in most cell types in body (indicating that vitamin D is important for most cell processes) -complex ‘turns’ on genes that are important in homeostatic control of minerals, especially calcium and phosphorous |
vitamin D
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is a hormone that mediates calcium balance (and phosphorus) in the body
-one form increases absorption of calcium from food -one form signals the release of bone calcium to maintain blood calcium levels, which are under homeostatic control -facilitates calcium in it’s regulatory role for neuromuscular activity, like heart muscle contraction |
vitamin D
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limits proliferation of cells (increasing numbers) and promotes differentiation (increasing types)
-may play a role in cancer prevention plays role in immunity Insulin production/use blood pressure regulation new roles are still being discovered |
vitamin
d |
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we eat it
----we MAKE it -few unfortified food sources -fatty fish (salmon, sardines, herring, mackerel), liver -fortified sources include cereal, milk (but check other dairy products), some orange juice -it is difficult to get adequate dietary vitamin D |
how we get vitamin D
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a cholesterol compound changes to a form of
vitamin D in the skin during exposure to sunlight (ultraviolet B) -the vitamin D travels in the bloodstream to the liver where it is converted to a more active form of vitamin D, then travels to the kidneys where it is converted to the most active form. |
making vitamin D
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_____ _____a measure of vitamin activity-an IU for 1 vitamin can’t be translated to another vitamin
AI is 15 ug/day (600 international units-IU) for adults younger than 70 -Needs increase with age AI was increased in 2010-one of the few nutrients to be recently revised |
international unit
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-expose unclothed limbs to sun for 10-15 minutes, between 10 am and 3 pm, for 3-5 times/week
(March –Oct) -face should always have sunscreen -no sunscreen on limbs (SPF 8 diminishes production by 80-90%) -tanning booth lights produce UV A not UV B -in northern states this is enough to provide adequate amounts all year (it is stored in adipose tissue) |
vitamin
d syntesized |
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achieved vitamin status because these are deficiency diseases associated with it
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vitamin
D |
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vitamin D deficiency
in infants and children -bones fail to mineralize -weight bearing causes limbs to bow -dark-skinned children are still at risk in the US |
ricketts
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- vitamin D deficiency in adulthood
- bones are ‘remodeled’ -calcium is taken up and laid back down on bone framework -calcium can’t be absorbed if vitamin D is deficient so bones become softer with time -can contribute to osteoporosis |
Osteomalacia
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-muscle weakness and pain
-low immunity -depression And, low vitamin D status is correlated with increased risk of -cancer (breast, prostate, colon) -diabetes (both 1 and 2) -Alzheimer’s disease -depression -autoimmune diseases -multiple sclerosis |
vitamin
D deficiencies |
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-breast fed infants (human milk does not contain adequate vitamin D)
-breast fed babies need sun exposure or supplementation -dark skinned people especially if they live far from the equator -people who are not exposed to sun -Mid-eastern women -professional drivers -older adults -nursing home residents -workers on odd shifts -the obese (fat grabs and stores) -people concerned with wrinkles |
people who are at risk
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UL for vitamin D is 100 ug/day (4000 IU/day). It has been revised with upward revision of AI.
-Toxicity can be achieved only through supplementation. -Higher doses can cause calcification of organs, kidney stones, bone loss -Vitamin D is a ‘hot’ nutrient, widely researched and in the news, so weigh what you hear carefully -much is said about the vitamin D deficiency of the US, estimated t be from 30-80% of population |
toxicity
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Be aware of claims and remember
10-15 minutes, 3-5 times/week (March-October) limbs exposed, sunscreen on face toxicity can’t occur with sunlight exposure |
vitamin D
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-fat soluble
-group of chemicals called tocopherols and tocotrienols -most active is alpha-tocopherol -gamma-tocopherol may have some lesser biological role |
vitamin E
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Functions:
-antioxidant, fighting oxidation of DNA, proteins and other metabolites -lesser role in platelet aggregation and nerve development and immunity Needs: RDA for adults is 15mg/day (natural or food source) |
vitamin E
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deficiencies are rarely seen, usually in cases of severe undernutrition
-people who eat low-fat diets for years become deficient -symptoms of severe deficiency are muscle weakness, loss of coordination and balance, retinal damage -infants deprived of vitamin E in breast milk or formula show red blood cell lysis |
vitamin E deficiency
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can be difficult to assess because symptoms are so broad
-vitamin E can be recycled -in US intakes are about 50-65% of need -smokers are prone to low Vitamin E status because of the excessive oxidative damage -low intake is associated with increased risk of chronic disease but no study has shown reversal with supplementation |
deficiency disease
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UL –1000mg/day (or 1500 IU/day)
Toxicity is difficult to detect -one symptom is decreased clotting time because it interferes with vitamin K -attained only through supplementation |
vitamin E toxicity
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-nuts (hazelnuts, peanuts, almonds)
-germs of grains (wheat germ), seeds -plant oils -widespread in foods but few rich sources -fortified cereal -_____ content of foods compro mised by light, deep-fat frying and oxygen |
food sources of vitamin E
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-synthetic vitamin E is a mix of tocopherols, most of which aren’t biologically active
-if taking supplements check to see it amount of vitamin E is measured as alpha-tocopherol -consider naturally produced vitamin E |
vitamin E supplements
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