Vitamin D is a group of fat-soluble compounds that consist of vitamin D2 (or ergocalciferol) and vitamin D3 or cholecalciferol the term vitamin D can also be used for the specific groups. When the skin is exposed to sunlight, it produces vitamin D, especially when there are ultraviolet rays involved. It greatly helps the immune system by producing such things like anti tumor bacteria that help fight disease.

Although several forms of vitamin D have been found and researched, the two major forms used today and vitamin D2 and vitamin D3. Vitamin D1 is a molecular compound of ergocalciferol with lumisterol. Vitamin D2 is an ergocalciferol or calciferol made from ergosterol. Vitamin D3 is a cholecalciferol made from 7-dehydrocholesterol in the skin. Vitamin D4 is a dihydrotachysterol and Vitamin D5 is a sitocalciferol made from 7-dehydrositosterol.

The different forms of vitamin D are in the form of broken up steroids. The side chains of the different vitamin Bs are different which makes them structurally different too. The skin produces vitamin D3 photochemically in the skin from 7-dehydrocholesterol. The way in which you can tell whether the vitamin is nutritional or not is through the interaction it has in the blood stream of humans.

Since there are not many natural sources of food for vitamin D, there exist many fortified foods that are vitamin D enriched. Natural sources include shitake mushrooms, fish liver oils, eggs and fatty fish.

A deficiency in vitamin D would mean it could lead to one of several bone diseases either now or in later life such as osteoporosis, ostemomalacia and rickets. As one gets older, the need for vitamin D becomes higher since it is harder for the body to produce its own from skin exposed to sunlight. Darker skinned individuals may need a higher dosage than lighter skinned people as the pigment may stop or slow down the production of vitamin D. it acts as a type of sun block. Overdose of vitamin D is also possible and the toxins of it are treated with a limitation or even an elimination of the vitamin.

Nowadays it is very common to see vitamin D in other manufactured products. Apart from obvious capsules that are there for supplementary purposes, there exist many other products such as vitamin D enriched cereals and other foods. These are helpful because natural sources of vitamin D are crucial, but cooking it in any fashion destroys the goodness of it. It is therefore important that enriched foods exist so humans can still acquire their RDA of vitamin D.

Because this vitamin is cheap to harvest and is grown and cultivated all around the world, especially through seafood, it is easy to see why it has become so popular. Used for medicinal and health benefits, it shows how much it has become part of our lives. It is recommended to take a certain amount of vitamins and minerals everyday to help our immune system stay working at 100%. It is also advised not to overdose on certain vitamins and minerals as they may cause serious side effects and affect certain bodily processes.

If you are unsure about taking supplements, contact your doctor or pharmacist. He or she can advise you on the best plan of action and give you more information about specific vitamins and minerals. It is advised to seek consultation especially if you are pregnant or currently taking any medication as this can affect the intake of supplements. Go to a registered pharmacy and make sure you read all the instructions on dosage and follow them strictly. More information can be found on the Internet too.