Vitamin D

What is Vitamin D

Vitamin D is not just a singular vitamin, it actually refers to a group of similarly structured molecules known as vitamers. These are primary involved in bodily functions such as calcium homeostasis and bone metabolism. This vitamin is somewhat unique in the human body in that it is one of the few nutrients that it is able to produce internally. It does however require some level of help from external factors. Vitamin D is made in the skin due to a reaction between ultraviolet light and cholecalciferol. Cholecalciferol is also called vitamin D3. It is not produced naturally in the body and must be ingested through the food you eat. Since pure vitamin D is actually not ingested but produced in the body, it is technically a hormone, or a chemical that your body produces. Cholecalciferol is most efficiently used when it is ingested with a lipid, or a fat. It is then sent to the liver where it is turned into a form that can be used to create vitamin D3.

Types of Vitamin D

• Vitamin D1 - Ergocalciferol
• Vitamin D2 - Ergocalciferol made from ergosterol
• Vitamin D3 - Cholecalciferol
• Vitamin D4 - 22-dihydroergocalciferol
• Vitamin D5 - sitocalciferol

Function of Vitamin D

The function of Vitamin D in the body is quite important. It plays a vital role in a process known as calcium and phosphorus homeostasis. It regulates bone growth and repair be affecting how much calcium is absorbed by the small intestine and by regulating how much calcium is lost during urination. It does this in the kidney, why filters the blood for substances to re released in urine, by working with the hormone estrogen in order to regulate the reabsorption of calcium and phosphorous back into the blood stream. It also works in the blood stream to determine how much calcium get sent to the bone system.

Vitamin D also appears to play an important role in human genetics as well. Its presence has been confirmed in over 50 human genes whose functions actually go beyond mineral absorption rates. Studies have shown that vitamin D can also have direct effects on nuclear receptors in the cells of the liver, thyroid, prostate and brain. Vitamin D has also been shown to work closely with the formation of white blood cells, which are the driving cell of the immune system.

Vitamin D Deficiencies

Unfortunately, vitamin D deficiencies are quite common in the United States today. Recent studies have shown that if you are above the age of 65, you have a 70% chance of having some sort of vitamin D deficiency. On top of this, studies have also shown that the average intake of vitamin D among Americans of any age is actually 30% below the recommended level. This can cause the disease called Rickets in children and osteomalacia in adults. These both result in weak bone structures that allow bones to bend and break. The bending of bones can be very painful, and if not treated it can become permanent. This can cause issues in mobility and overall health. Vitamin D deficiencies can result in insufficient intake, lack of exposure to sunlight or dysfunctions with the kidney or liver.

Vitamin D Sources

The most effective source of vitamin D is actually the sun. In order to get a daily dose of vitamin D, it is recommended that you get at least 20 minutes of sun exposure every day. The ultraviolet light reacts with the vitamin D3 in your body to create vitamin D. The most popular dietary source of vitamin D3 is vitamin D enriched milk and dairy products. It can also be found in soy products, cod liver, cereal and other fatty fish oils.