Vitamin D - The Sunshine Vitamin

Vitamin D is known as the "sunshine vitamin" because the sun helps the body generate its own supply.  The amount of sun exposure that is needed for the body to generate a sufficient supply of this vitamin depends on your skin color and pigment. The time required can range from half an hour to more than three hours.  Interestingly, with the heightened awareness of skin cancer, doctors have begun to see documented cases of deficiencies as more and more people are staying out of the sun. 

 Vitamin D helps to regulate the balance of phosphorus in the body. In addition, it is valuable in maintaining the heart muscle and protecting the nerves from damage and deterioration. It increases the absorption of calcium, thereby assisting in the maintenance of proper bone density. It also has import effects in thyroid stimulation and blood clotting.

Those seeking a higher level of fitness will appreciate the ability of vitamin D to protect bone mass and prevent exercise related injuries caused by brittle bones.

Food Sources
Tuna, salmon, mackerel, sardines and kipper, as well as egg yolks, liver, and butter.

Recommended Dosage
The Reference Daily Intake (RDI) is 400 IU.

Supplements
There are two forms of vitamin D:  vitamin D2 (ergocalciferol) and D3 (cholecalciferol).  D3 is the preferred form since it is the naturally occurring form.  Vitamin D supplements are generally taken in doses of 400 IU.

Vitamin D combines well with Vitamin A, calcium, and phosphorus.

Vitamin D supplements should be stored in a cool, dark location out of direct sunlight.

Side Effects & Toxicity
The established toxicity rate has been established at 5000 IU, but experts recommend not exceeding a daily dose of 600 IU. Excessive amounts can lead to too much calcium in the blood, low appetite, increased thirst, nausea, vomiting and abdominal pain. In addition, excessive concentrations can lead to calcium deposits in soft tissues. This can be a severe health concern, particularly for older people.

Symptoms of Deficiency
Deficiency can result in softening of bone, muscle cramps, convulsions and loss of calcium and other minerals. Common symptoms of deficiency include a burning sensation in the throat, diarrhea, insomnia and problems with vision. Deficiencies can also cause a disease known as rickets. Rickets results in brittle bones in children; for this reason milk is fortified with vitamin D.