Properties of vitamin K

Vitamin K comprises derivatives of 1,4-naphthiquinone. Naturally occurring forms are equipped with structures possessing the unsaturated isoprenoid side chain linked to naphthoquinones at crabon-3.

Vitamin K also fat soluble. It is essential for the synthesis of prothrombin a compound involved in the clotting of blood.

Vitamin K is mostly needed to help to stop bleeding, but it has some other jobs as well.

It is a cofactor specific to the formation of –carboxyglutamyl residues from specific glutamate residues in certain proteins.

The most important is the crucial role vitamin K, plays building bones. Vitamin K is needed to help hold onto the calcium in bones and make sure it’s getting to the right place.

It actually comes in three different forms: First, there’s vitamin K1, or phylloquinone. This is the form of vitamin K found in plant foods.

Vitamin K1 is quite stable to oxidation and most food processing and food preparation procedures. It is unstable to light and alkaline conditions.

Next, there’s Vitamin K2, also called menaquinone. This the form friendly bacteria in the intestines make. 

The last form would be called vitamin K3. It is also called menadione. Menadione is the only formed isolated from Staphylococcus aureus and also chemically synthesized. It is a synthetic compound that can be converted into K2 in the gastrointestinal tract.

All  vitamin K ends up in liver, where it’s used to make some of the substance that make blood clot.
Properties of vitamin K

Roles of vitamin A in human body

Vitamin A, a fat soluble nutrient has an important role in embryonic growth, vision and resistance to infection.

It is also involved in the regulation of various physiological functions such as gene expression, maintenance of immune system and red blood cell production.

Vitamin A is a generic term for all retinoids that qualitatively exhibit the biological activity of all-trans retinol. It has a clearly defined role in vision: when retinal tissue is deprived of vitamin A, rod and cone function is impaired.

It is also required for the integrity of epithelial cells throughout the body, via the regulatory action of retinoic acid at the level the gene.

A main dietary source of vitamin A are the carotenoids from fruits and vegetables. These carotenoids seem to have separate function as antioxidants in addition to their provitamin A function.

Active vitamin A is found only in animal sources. It is especially high in the fish liver oil from cod, halibut, salmon and shark. It is also found in beef and chicken liver and in eggs and dairy products.

Beta carotene, the vitamin A precursor, is found only in green and yellow orange fruits and vegetables, such as carrots, kale, kohlrabi, parsley, spinach turnip green and cantaloupe.

Vitamin A deficiency is rare in the US, but it is still a major public health problem in the developing world. It is most often associated with protein/calorie malnutrition and affects over 120 million children worldwide.

As early as 1500 BC, clinical symptoms of vitamin A deficiency such as night blindness were described by the Egyptians. Furthermore, the importance of vitamin A for resistance to infectious disease has been known for almost hundred years.

Extremely dry skin, dry hair, sloughing off of skin, and broken fingernails are other common signs of vitamin A deficiency. Vitamin A deficiency also decreases resistance to infections, and may contribute to the pneumonia associated with vitamin A deficiency.
Roles of vitamin A in human body

Water soluble Vitamins

Vitamin are chemically unrelated organic substances that are grouped together because each is essential in the diet in minute amounts and is required for specific metabolic reactions within the cells. Traditionally they are classified according to their solubility water and fat solvents and, from a physiological standpoint; this property determines the pattern of transport excretion and storage within the human body.

Several of the vitamins, while conveniently considered as a single substance, actually are a group of structurally related compound that tend to behave alike physiologically. In general however, physiologically function tends to be limited to one active form to which the related forms are converted.

Whether a substance must be supplied intact to the cell or can be synthesized by the cell depends on the assortment of enzymes peculiar to the cell species. A substance, therefore, may be a vitamin for one species but not for another. The difference lies whether the substances is required in the diet or whether it can be synthesized by human body.
Vitamin