Question

Choose one of the four(4) fat-soluble vitamins to talk about. List what vitamin you chose, what food sources are best for this vitamin, discuss the importance of this vitamin in the body, and any consequences that occur in the body if this vitamin is not consumed in adequate amounts or if this vitamin is consumed in excess.

Answer 1

Ans) Vitamin A:

- Fat soluble, helps with skin/ vision and reproduction & makes white blood cells, sources= dairy, liver, dark fruits and vegies

Forms of Vitamin A
Preformed- Retinol, Retinal, Retinoic acid, Proformed (provitamins)- Cerotenoids

Preformed vitamin- do not have to be converted, biologically active (animal sources)

Proformed vitamin- must be converted to retinoid form ( biologically active)

Food sources for vitamin A (retinol):
liver, fish, fish oil, milk, cheese, eggs

food sources for vitamin A (Carotenoids):
sweet patatoes, carrots, dark green, deep yellow, orange fruit and veggies

Men RDA vitamin A: 900 micrograms

women RDA vitamin A: 700 micrograms

Absorption of vitamin A- packaged with chylomicrons, transported via lymphatic system to liver.

Transportation of vitamin A
- transported by the blood stream for body use. Retinoids bound to retinol binding protein.

- Carotenoids carried by very low density lipoproteins

Excretion of vitamin A- in a small amount in the urine

Function of Vitamin A (retinoids):
- Growth and development. makes specialized cells in the eye (cornea, retina) fetal development: eyes, limbs, cardiovascular, and nervous system.

Lack of vitamin A (pregnancy)- birth defects, fetal mortality

Rhodopsin (made up of): retinal + opsin=

Rhodopsin is used for- to see in the dark, black/white images. (rods/cones that absorb light)

Deficiency causes:

Night blindness- can be caused by deficient in Vitamin A. Can not see in dim light.

Xerophthalmia- eye disease dryness of cornea, eye membrane, major cause of blindness

follicular hyperkeratosis- skin disorder with rough , sandy texture skin

hypervitaminosis A- vitamin A toxicity generally caused by long term supplement use

Acute vitamin A toxicity- short period of large dose of vitamin A

Chronic vitamin A toxicity- large dose of vitamin A overtime repeatedly

teratogenic- can cause birth defects.

conjuctival dryness- roughness, wrinkles in white part of eye

corneal lesions- clear part of eye is damaged- blindness, irreversible.