What is vitamin D?

The term "vitamin D" refers to several different forms of this type of vitamin. Two forms are important to the human body:  Vitamin D2 (ergocalciferol) and, Vitamin D3 (cholecalciferol).  Vitamin D2 is synthesized by plants. Vitamin D3 is synthesized by humans in the skin when it is exposed to ultraviolet-B (UVB) rays from sunlight. Foods may be fortified with vitamin D2 or D3.

Where is vitamin D found?

Vitamin D is found in many dietary sources such as fish, eggs and fortified milk. The sun also contributes significantly to the daily production of vitamin D, and as little as 10 minutes of exposure is thought to be enough to prevent Vitamin D deficiency.

What are the benefits of vitamin D?

The major biologic function of vitamin D is to maintain normal blood levels of calcium and phosphorus. Vitamin D aids in the absorption of calcium, helping to form and maintain strong bones.

What are the symptoms of vitamin D deficiency?

•  In children, severe vitamin D deficiency causes rickets (softening of the bones because of lack of calcium), which results in skeletal deformities.

• Other milder symptoms include muscle aches, bone pain & weakness.

•  In adults, vitamin D deficiency can lead to osteomalacia, which results in muscular weakness in addition to weak bones.

•     Low blood calcium levels (hypocalcemia).

•     High Levels of Parathyroid hormone.

•    People vulnerable to Vitamin D deficiency including elderly individuals, Obese individuals, people less exposed to sunlight, babies dependent on breast milk without supplements.

Diseases and symptoms linked to Vitamin D deficiency:

Low levels of Vitamin D have been linked to increased risk of cancers such as colon, breast and prostate cancer. Low Vitamin D levels also contribute to muscle weakness, increased risk of multiple sclerosis, congestive heart failure, lung function, autoimmune diseases, diabetes, schizophrenia, depression and osteoporosis. Hence, understanding the true levels of Vitamin D within the body is of real importance to all.

Populations who may be at a high risk for vitamin D deficiencies include the elderly, obese individuals, exclusively breastfed infants, and those who have limited sun exposure. Also, individuals who have fat malabsorption syndromes (e.g. cystic fibrosis) or inflammatory bowel disease (e.g. Crohn's disease) are at risk.

What are the tests performed to detect vitamin D deficiency?

•     Vitamin D2 & D3 (Total Vitamin D) test by LC-MS/MS Tandem Mass Spectrometry

•     Parathyroid hormone (PTH)

•     Alkaline phosphatase

•     Phosphorus, serum

•     Calcium, urine

• ‏    Calcium, serum