Vitamins "vital amine," are organic molecules (C, H, N, or O) that are needed in trace amounts to help catalyze

many of the biochemical reactions in the body.Generally obtained from dietary sources.

Thirteen vitamins have been shown to be

essential for normal growth and health in

humans

What are the important differences between fat and water soluble vitamins?

Fat-soluble vitamins that we need include vitamins A, D, E and K. Fat-soluble vitamins

dissolve in fat and therefore can be stored in the fatty tissues of the body.

As a consequence, we do not need to ingest fat-soluble vitamins daily.

The body can use these stores when the intake of fat-soluble vitamins is low.

Vitamin D is necessary for the proper formation of bones

A metabolic bone disease from vitamin D deficiency. It is called rickets in children and osteomalacia in adults. Both cause softening and weakening of bones because of

defective or inadequate bone mineralization.

Vitamin D3 (cholecalciferol)

Testosterone (a steroid hormone)

Cholesterol (a sterol)

Cholesterol is produced by the liver – found in all body tissues –

Helps organize cell membranes & control their permeability. Cholesterol derivatives in the skin are converted to vitamin

D when the skin is exposed to sunlight. Vitamin D3 mediates intestinal calcium absorption and bone

calcium metabolism

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Beta-carotene is the provitamin for vitamin A, that is, it can be converted to vitamin A.

Vitamin A is an unsaturated alcohol, which maintains good eyesight. A deficiency in the diet leads to a degeneration of the structure of the eye.

Vitamin A (also called retinol) is fat-soluble, and as such, can be stored in the fatty tissues of the body. We obtain vitamin A either directly from foods that are substantial in vitamin A (beef liver, fish liver oils, egg yolks and butter, for example) or by converting a substance called beta-carotene into vitamin A.

Physiological Aspects of Vitamin E

Vitamin E is absorbed in the intestines.

The majority of the absorbed vitamin E is delivered to the liver, where it is then secreted into the circulation for delivery to tissues.

Anti-oxidant activity of Vitamin E:H on the hydroxyl group of the Vitamin E ring can be

donated to neutralize a free radical (creating a more stabile tocopheroxyl radical).

Polar ring stays near edges of plasma membrane.When a phospholipid tail becomes peroxidized by a free radical, the tail becomes more polar and migrates to the

edge where it gets neutralized by the vitamin E.

Vitamin E is present in animal fats, cereal grains and nuts.

Alpha-tocopherol is found in a number of oils, including safflower and sunflower.

It is also found in wheat germ. Soybean and corn oils contain mainly gamma-tocopherol.

The Anti-Hemorrhagic Vitamin: Vitamin K

Present in green leafy vegetables was required for normal coagulation of the blood.

The "K" in vitamin K comes from the German word "koagulation" (coagulation).

Vitamin K is essential for the functioning of several proteins involved in normal blood clotting.

When a cut occurs, complex series of

events acts to stop the bleeding.

Blood clotting is body's response to

tissue injury.

Constriction of ruptured vessel - proteins soon start "coagulation cascade:" Interaction of coagulation factors, platelets and the damaged vessel itself. Clot forms = protective barrier.Clot breaks down as wound heals

There are several forms of vitamin K, namely: 1.Vitamin K1 (phylloquinone) 2.Vitamin K2 (menaquinone) 3.Vitamin K3 (menadione)

Vitamin K1 or "phylloquinone”

Major dietary source of vitamin K:Green leafy vegetables like lettuce, kale, parsley, spinach and various greens (turnip, beet and mustard). Broccoli is also a good source of vitamin K1 as are certain vegetable oils (soybean, cottonseed, canola, and olive).

Vitamin K2 is actually a group of compounds called the "menaquinones" distinguished by the# of isoprene residues in side chain of the vitamin K2 molecule or by # of C in the side chain. e.g. menaquinone-8 (MK-8) has 8 isoprene units in side chain