Vitamin D : Important at Every Age

                        

Vitamin D is a fat soluble vitamin that plays a vital role in the human body. It has many functions, and a lack of vitamin D can lead to many health problems.

    

The body needs vitamin D to absorb calcium. Without enough vitamin D, one can’t form enough of the hormone calcitriol (known as the “active vitamin D”). This in turn leads to insufficient calcium absorption from the diet. In this situation, the body must take calcium from its stores in the skeleton, which weakens existing bone and prevents the formation of strong, new bone.

*** How Much Vitamin D Do I Need?

• An average healthy adult between the ages of 19 and 50 should receive about 200 IU's of vitamin D a day.
• Older adults should have higher levels to ensure proper bone maintenance.
• Recommendations for those between the age of 51 and 70 is 400 IU and 600 IU for people over the age of 70. However, these numbers are low level recommendations to avoid severe deficiency.
• In most cases, higher levels are healthy. Vitamin D toxicity is possible but very unlikely.
• Vitamin D supplementation is very common to those suffering from deficiency or at risk for osteoporosis.

*** You can get vitamin D in three ways :

• Through the skin, (exposure to sunlight) 
• From the diet,
• From supplements.

                     

Experts recommend a daily intake of 600 IU (International Units) of vitamin D up to age 70. Men and women over age 70 should increase their uptake to 800 IU daily, which also can be obtained from supplements or vitamin D-rich foods such as egg yolks, saltwater fish, liver, and fortified milk.

*** Various forms of vitamin D

We know about 5 forms of vitamin D, of which vitamins D₂ and D₃ are the major forms as far as humans are concerned. They are known collectively as calciferol.

• Vitamin D₁, molecular compound of ergocalciferol with lumisterol.


• Vitamin D₂, ergocalciferol (made from ergosterol).
  
  It is produced by invertebrates (animals without a spine, vertebral column), fungus and plants in response to sunlight (UV irradiation). Humans and other vertebrates do not produce vitamin D₂.

• Vitamin D₃, cholecalciferol (made from 7-dehydrocholesterol).
  
  Vitamin D₃ is made in the skin when 7-dehydrocholesterol reacts with ultraviolet light at 270-300 nm wavelengths - peak vitamin D₃ production occurs between 295-297 nm. It is only when the UV index is greater than 3 that these UVB wavelengths are present.
  
  A human requires ten to fifteen minutes of sun exposure at least twice a week on the face, arms, hands, or back without sunscreen with a greater than 3 UV index for adequate amounts of vitamin D₃. Longer exposure results in the extra vitamin supply being degraded as fast as it is generated.


• Vitamin D₄, 22-dihydroergocalciferol.


• Vitamin D₅, sitocalciferol (made from 7-dehydrositosterol).

• Which is more important for humans, vitamins D₂ or D₃?

Both vitamins D₂ and D₃ are used in human nutritional supplements. 

Pharmaceutical forms include calcitriol (1alpha, 25-dihydroxycholecalciferol), doxercalciferol and calcipotriene. 

The majority of scientists state that D₂ and D₃ are equally effective in our bloodstream. However, some say that D₃ is more effective.

*** What do we need vitamin D for?

• It is crucial for the absorption and metabolism of calcium and phosphorous, which have various functions, especially the maintenance of healthy bones.


• It is an immune system regulator.


• It may be an important way to arm the immune system against disorders like the common cold, say scientists from the University of Colorado Denver School of Medicine, Massachusetts General Hospital and Children's Hospital Boston.


• It may reduce the risk of developing multiple sclerosis. Multiple sclerosis is much less common the nearer you get to the tropics, where there is much more sunlight, according to Dennis Bourdette, chairman of the Department of Neurology and director of the Multiple Sclerosis and Neuroimmunology Center at Oregon Health and Science University, USA.


• Vitamin D may have a key role in helping the brain to keep working well in later life, according to a study of 3000 European men between the ages of 40 and 79.


• Vitamin D is probably linked to maintaining a healthy body weight, according to research carried out at the Medical College of Georgia, USA.


• It can reduce the severity and frequency of asthma symptoms, and also the likelihood of hospitalizations due to asthma, researchers from Harvard Medical School found after monitoring 616 children in Costa Rica.


• It has been shown to reduce the risk of developing rheumatoid arthritis in women.


• A form of vitamin D could be one of our body's main protections against damage from low levels of radiation, say radiological experts from the New York City Department of Health and Mental Hygiene.


• Various studies have shown that people with adequate levels of vitamin D have a significantly lower risk of developing cancer, compared to people with lower levels. Vitamin D deficiency was found to be prevalent in cancer patients regardless of nutritional status, in a study carried out by Cancer Treatment Centers of America.


• High vitamin D doses can help people recover from tuberculosis more rapidly, researchers reported in September 2012 in the Proceeding of the National Academy of Sciences (PNAS).


• An additional study published in September 2012 suggested that low levels of vitamin D may increase the risk of heart attack and early death.

 

*** More Functions of Vitamin D
Vitamin D has other roles in the body. It is used in the maintenance of several organ systems as well as the immune system.  Because of its important funstions, vitamin D deficiency can lead to many other health problems.  

Heart disease, arthritis, diabetes, high blood pressure, and even cancer have been associated with a lack of vitamin D. Additionally, new studies suggest that vitamin D may play a role in protecting against Alzheimer's and Parkinson's disease.

Pregnant women, at greater risk of malnutrition, should closely monitor their vitamin D intake. It has been shown that those with low levels have given birth to children with low bone density.

• How do I get tested? 

Ask your doctor for a vitamin D test. 

Be specific and ask for a 25(OH)D test. There is another type of blood test for vitamin D, called  a 1,25(OH)₂D test, but the 25(OH)D test is the only one that will tell you whether you’re getting enough vitamin D.  

This test little bit costly so If your doing this test in large group then you may get some discount from lab.