The Fat-Soluble Vitamins A, D, E, and K Copyright 2005 Wadsworth Group, a division of Thomson Learning

The Fat-Soluble Vitamins Copyright 2005 Wadsworth Group, a division of Thomson Learning

Vitamin A And Beta-Carotene Other names –Retinol –Retinal –Retinoic acid –Precursors are carotenoids such as beta-carotene Retinoids and carotenoids –Vitamin A activity Copyright 2005 Wadsworth Group, a division of Thomson Learning

Vitamin A And Beta-Carotene Copyright 2005 Wadsworth Group, a division of Thomson Learning

Vitamin A And Beta-Carotene Retinol-binding protein (RBP) –Because it is fat soluble, Vitamin A cannot travel by itself in the blood –Picks up Vitamin A from the liver and carries it in the blood There are receptors for the various forms of Vitamin A on cells that use it Each form of Vitamin A has its own receptor with Retinol having multiple receptors Copyright 2005 Wadsworth Group, a division of Thomson Learning

Roles in the body –Vitamin A in vision Copyright 2005 Wadsworth Group, a division of Thomson Learning Vitamin A And Beta-Carotene

Roles in the body –In vision Helps maintain Cornea Active component of Retina –In protein synthesis and cell differentiation Maintains skin and mucus membranes –Promotes differentiation of epithelial and goblet cells (which synthesize and secrete mucus on the various internal surfaces of the body) –In Reproduction and growth Pariticipates in sperm development Supports normal fetal development –As antioxidant Betacarotene an antioxidant protects body against disease –In Immunity Copyright 2005 Wadsworth Group, a division of Thomson Learning Vitamin A And Beta-Carotene

Copyright 2005 Wadsworth Group, a division of Thomson Learning Recommendations –Retinol activity equivalents (RAE) –1ug (microgram) of retinol = 12 micrograms of dietary beta carotene Sources –Retinol: fortified foods milk, cheese, cream, butter, fortified margarine, eggs, liver –Beta-carotene: Brightly colored fruits and vegetables Spinach and dark green leafy vegetables, broccoli cantaloupe apricots, squash carrots, sweet potatoes NOT celery, cabbage, beets, corn –Liver extremely high amounts chances of toxic overdose

Vitamin A And Beta-Carotene Deficiency disease: hypovitaminosis A Deficiency symptoms –Night blindness (slow recovery of vision after bright light or inability to see in dim light) –Blindness (xerophthalmia) corneal degeneration and blindness corneal drying (xerosis) and softening of the cornea (keratomalacia) –Impaired immunity (infections) –Plugging of hair follicles with keratin, forming white lumps (hyperkeratosis) –Keratinization (rough skin) –Decline in mucus cells lining the GI and elsewhere Copyright 2005 Wadsworth Group, a division of Thomson Learning

Vitamin A And Beta-Carotene Excess betacarotene from natural sources turns skin yellow but ok But supplements can be dangerous Toxicity disease: hypervitaminosis A Copyright 2005 Wadsworth Group, a division of Thomson Learning

Vitamin A And Beta-Carotene Chronic toxicity symptoms –Increased activity of osteoclasts causing reduced bone density –Liver abnormalities –Birth defects Acute toxicity symptoms –Blurred vision –Nausea, vomiting, vertigo –Increase of pressure inside skull, mimicking brain tumor –Headaches Copyright 2005 Wadsworth Group, a division of Thomson Learning

Vitamin D Is actually a hormone Other names –Calciferol –1,25-dihydroxy vitamin D (calcitriol) –Animal version: vitamin D 3 or cholecalciferol –Plant version: vitamin D 2 or ergocalciferol –Precursor is the body’s own cholesterol Copyright 2005 Wadsworth Group, a division of Thomson Learning

Vitamin D Chief functions in the body –Mineralization of bones (raises blood calcium and phosphorus by increasing absorption from digestive tract, withdrawing calcium from bones, stimulating retention by kidneys) –May also be important for immune system, nervous system, skin and reproductive organs –May protect against multiple sclerosis Copyright 2005 Wadsworth Group, a division of Thomson Learning

Vitamin D Significant sources –Synthesized in the body with the help of sunlight –Fortified milk, margarine, butter, cereals, and chocolate mixes –Veal, beef, egg yolks, liver, fatty fish (herring, salmon, sardines) and their oils Copyright 2005 Wadsworth Group, a division of Thomson Learning

Vitamin D Deficiency diseases –Rickets –Osteomalacia Copyright 2005 Wadsworth Group, a division of Thomson Learning

Vitamin D Deficiency symptoms: rickets in children –Inadequate calcification, resulting in misshapen bones (bowing of legs) –Deformities of ribs (bowed, with beads or knobs) –Lax muscles resulting in protrusion of abdomen –Muscle spasms Copyright 2005 Wadsworth Group, a division of Thomson Learning

Vitamin D Deficiency symptoms: rickets in children (continued) –Delayed closing of fontanel, resulting in rapid enlargement of head Copyright 2005 Wadsworth Group, a division of Thomson Learning

Vitamin D Deficiency symptoms: osteomalacia in adults –Loss of calcium, resulting in soft, flexible, brittle, and deformed bones –Progressive weakness –Pain in pelvis, lower back, and legs Copyright 2005 Wadsworth Group, a division of Thomson Learning

Vitamin D Toxicity disease: hypervitaminosis D Toxicity symptoms –Elevated blood calcium –Calcification of soft tissues (blood vessels, kidneys, heart, lungs, tissues around joints) –Frequent urination Copyright 2005 Wadsworth Group, a division of Thomson Learning

Vitamin E Other name: alpha-tocopherol Chief function in the body –Antioxidant (stabilization of cell membranes, regulation of oxidation reactions, protection of polyunsaturated fatty acids and vitamin A) Copyright 2005 Wadsworth Group, a division of Thomson Learning

Vitamin E Copyright 2005 Wadsworth Group, a division of Thomson Learning

Vitamin E Significant sources –Polyunsaturated plant oils (margarine, salad dressings, shortenings) –Leafy green vegetables, wheat germ, whole grains, liver, egg yolks, nuts, seeds Copyright 2005 Wadsworth Group, a division of Thomson Learning

Vitamin E Easily destroyed by heat and oxygen Deficiency symptoms –Red blood cell breakage –Nerve damage Toxicity symptoms –Augments the effects of anticlotting medication Copyright 2005 Wadsworth Group, a division of Thomson Learning

Vitamin K Other names –Phylloquinone –Menaquinone –Menadione –Naphthoquinone Copyright 2005 Wadsworth Group, a division of Thomson Learning

Vitamin K Chief functions in the body –Synthesis of blood-clotting proteins and bone proteins that regulate blood calcium –Given to newborns to prevent hemorrhaging (bleeding) Copyright 2005 Wadsworth Group, a division of Thomson Learning

Vitamin K Significant sources –Bacterial synthesis in the digestive tract –Liver –Leafy green vegetables, cabbage-type vegetables –Milk Copyright 2005 Wadsworth Group, a division of Thomson Learning

Vitamin K Deficiency symptoms –Hemorrhaging Toxicity symptoms –None known Copyright 2005 Wadsworth Group, a division of Thomson Learning

The Fat-Soluble Vitamins - In Summary Interactions with each other Interactions with minerals Copyright 2005 Wadsworth Group, a division of Thomson Learning