Nutrition: Fat Soluble Vitamins A, D, E, K -1

General properties of fat soluble vitamins:

- Soluble in fat and fat solvents

- Contains only carbon, hydrogen, and oxygen

- May have precursors or provitamins

- Absorbed into lymphatic system

- Daily intake is not critical

- Intake in excess of daily needs are stored

- Deficiency symptoms slow to develop

- May be toxic at relatively low levels

vitamins that are able to be stored in the body:

fat soluble vitamins (stored in liver - vitamins and in fat tissues - carotenoids)

which type of vitamins can you risk toxicity when consumed in excess?

fat soluble vitamins

name the fat soluble vitamins:

A, D, E, K

What elements do fat soluble vitamins only contain?

carbon, hydrogen & oxygen

where are fat soluble vitamins absorbed?

lymphatics

T/F: daily intake of fat soluble vitamins is critical

false (intake in excess of daily needs are stored)

Retinol is very potent so it should not circulate in the blood. How does it circulate?

Retinol circulates bound to proteins

which vitamin is structurally related to the lipid alcohol retinol?

vitamin A

source of vitamin A only produced by plants & lower organism, e.g. algae. Can be converted into vit A:

provitamin A/carotenoids

The active form of Vitamin A:

Retinoids (vitamin A)

The pre-active form of Vitamin A:

Beta-carotene (body can convert to active form)

refers to retinol, its endogenous metabolites, & synthetic analog.

retinoids

derivative of vitamin A found in food, stores:

retinyl esters (vitamin A alcohol + fatty acid)

derivative of vitamin A found in blood circulation:

retinol (vitamin A alcohol)

derivative of vitamin A found in vision:

retinal (vitamin A aldehyde)

derivative of vitamin A found in gene expression:

retinoic acid (vitamin A acid)

What carotenoids do not have vitamin A activity?

Lycopene, lutein, zexanthin (>90% of the ~600 identified carotenoids)

- The rest of the carotenoids can produce vitamin A

on the food pyramid, what group gives you the highest source of vit A?

fruits and vegetables

foods high in vitamin A are associated with the color:

orange (or yellow)

What foods surpass the RDA value for Vitamin A for men and women?

Beef liver

Sweet potato

Carrots

Kale

Broccoli

liver is a good source of:

vitamin A

milk is a good source of:

vitamin A

cheese is a good source of:

vitamin A

eggs is a good source of:

vitamin A

yellow and orange veggies are a good source of:

provitamin A/carotenoids

green leafy veggies are a good source of:

provitamin A/carotenoids

which vitamin is important for vision?

vitamin A

in the presence of vitamin A, epithelial cells will produce:

mucous

in the absence of vitamin A, epithelial cells will produce:

keratin

T/F: keratinization is reversible

false (Xerosis is reversible)

What is conjunctival xerosis?

Dryness of eye membranes

headache, nausea, vomiting, drowsiness are symptoms of what type of vit A toxicity?

acute

skin and mucous membranes, musculoskeletal, and neurogenic defects are symptoms of what type of vit A toxicity?

Chronic

What part of the body has lots of signs indicating a vitamin A deficiency?

Lots of signs in the eye (night blindness, follicular hyperkeratosis, xerophthalmia, blindness)

Biological roles of vitamin A:

- Vision (not retinoic acid)

- Bone growth

- Reproduction (not retinoic acid)

- Cell division / cell differentiation (retinoic acid)

- Regulation of the immune system

- Antioxidant that protects cells from free radicals

The following is a sign of what vitamin deficiency: Night blindness

Vitamin A

The following is a sign of what vitamin deficiency: Bitot's spot: gray-white patches on surface of eye

Vitamin A

The following is a sign of what vitamin deficiency: Keratinization (hardening) of eye tissue

Vitamin A

The following is a sign of what vitamin deficiency: Keratinization of cornea --> permanent blindness

Vitamin A

The following is a sign of what vitamin deficiency: Xerosis: drying out of eye tissue

Vitamin A

The following is a sign of what vitamin deficiency: Skin changes "toad skin"

Vitamin A

How does the bone change with elevated levels of Vitamin A?

Studies suggest that elevated levels of vitamin A may cause increased bone resorption and promote development of osteoporosis

what vitamin is used in synthetic form to treat acne in the form of teratogens?

vitamin A (retinoids)

women who have used retinoid medications should not get pregnant for ______ years after cease of usage

3 years

women who used retinoids for acne treatment must use birth control for at least 6 months after stopping the treatment because of the drug being stored in the ______

liver

Patient presents with complains of visual impairment during the night time. You suspect that the patient has a deficiency in what vitamin?

Vitamin A

on the food pyramid, what group gives you the highest source of vit E?

plant oils and salad dressing

what vitamin has been deemed essential for reproduction?

vitamin E

Tocopherol: Greek for "to bear offspring", is the name for what vitamin?

vitamin E

what is the RDA for adults for a-tocopherol?

15 mg/day (typical American diet is 5-20 mg/d which is sufficient)

What foods could contribute to the RDA adult men and women for vitamin E?

Safflower oil, sunflower oil, almonds, sunflower seeds

which vitamin is used to provide antioxidants within the cell membrane and also has contributions in preventing cancer?

vitamin E

which vitamin helps prevent hemolysis of RBCs?

vitamin E

What are results of vitamin E deficiencies?

Rare in humans -->

Premature infants fed commerical formula low in Vitamin E - irritability, edema, hemolytic anemia -->

Abetalipoproteinemia - severe neurological abnormalities; prevented with Vitamin E supplementation

name three populations that need extra vitamin E?

- premature infants

- people with fat malabsorption

- individuals with rare genetic disorders

nausea, headache, fatigue, easy bruising and bleeding inhibition of platelet aggregation, diplopia (at dosages as low as 300 IU), muscle weakness, and creatinuria of what type of vit E toxicity?

Acute

Include symptoms of acute toxicity and Suppression of other antioxidants, Increased risk of hemorrhagic stroke are of what type of Vit E toxicity?

Chronic

which vitamin is a precursor for coagulation (blood clotting)?

vitamin K

What percent of vitamin K is made by bacteria in your large intestine?

~10% of daily value

what color foods are associated with being a good source of vitamin K?

green

What foods surpass the AI for Vitamin K for adult men and women?

Broccoli

Brussel sprouts

Turnip greens

Spinach

Kale

which sex needs more vitamin K?

males

what type of patients should not eat a lot of vitamin K?

patients of blood thinners (ex: Coumadin)

bacteria in the gut is able to make what vitamin?

vitamin K

a patient on antibiotics needs more of what vitamin?

vitamin K

What three populations need extra vitamin K?

- Individuals with certain medication

- Infants who are exclusively breastfed

- Individuals with fat malabsorption

vitamin K toxicity is most common in what population?

infants

Vitamin K deficiency:

- Uncommon in adults

- Newborn infants

- Antibiotic - long term use depletes the levels of vitamins K

- Associated with fat malabsorption

- Drugs interfering with vitamin K metabolism