Vitamin D is referred to as a fat-soluble vitamin when in fact it is a pre-hormone, necessary for many body functions. It is stored in fatty tissue for longer periods of time.
Vitamin D is often considered the “sunshine” vitamin since production is stimulated through exposing the skin of your face, arms, back, or legs (without sunscreen) in the sun. It is said that 10-15 minutes of sunshine three times weekly is enough to produce the body’s requirement of Vitamin D.
Unfortunately, many people live in regions where days are predominantly cloudy, or have high pollution, or live in countries where full clothing is necessary, leaving the individuals with Vitamin D deficiencies.
Most of the positive effects of solar radiation are linked to ultraviolet-B (UVB) rays which are responsible of Vitamin D production in skin.
Some foods contain high amounts of Vitamin D, such as fatty fish (salmon & mackerel), grain cereals, oysters, caviar, fortified daily products, as well as soy products, but it is almost impossible to receive sufficient vitamin D from the diet. Be aware that some of these food sources may also be high in heavy metals; i.e. fish.
Vitamin D plays a vital role in the calcium & phosphorous absorption. A lack of Vitamin D in early age can cause bone and tissue malformation. Vitamin D-deficient children are known to suffer from rickets and osteoporosis later in life. Vitamin D also helps to keep the immune system strong and provides a protection from autoimmune diseases, hypertension, and infectious disease. Low vitamin D levels have been associated with an increased risk of developing cancer. Vitamin D deficiency has been linked to depression.
Kjaergaard M, Waterloo K, Wang K etc al. Effects of Vitamin D supplement on depression scores in people with low levels of serum 25-hydroxyvitamin D: nested case-control study and randomised trial. Br J Psychiatry. 2012 Jul 12.
A Vitamin D deficiency is a common occurrence, though often overlooked, which can result from:
- Lack of exposure to sunlight as outlined above and a lack of enough vitamin D in the diet
- Liver and kidney diseases
- Poor food absorption
- Use of certain medicines, including phenytoin, phenobarbital, and rifampin
Higher-than-normal levels of Vitamin D may be due to, a condition called Hypervitaminosis D, also known as Vitamin D toxicity. It is a rare but potentially serious condition that occurs when too much vitamin D is supplemented.
Vitamin D is easily measured in Serum, and the 25-hydroxy vitamin D test is considered the most accurate.
The test is simple and inexpensive.
Optimum Value in Serum is 40-60 µg/l.
Test material: 3ml Serum
- 25-Hydroxy-Vitamin D (25-OH-D), Calcifediol, Total
- 1,25-Dihydroxy-Vitamin D (1,25-(OH)2D3), Calcitriol